New Assay Test Predicts That 50% of Ovarian Cancers Will Respond To In Vitro PARP Inhibition

U.K. researchers develop a new test that could be used to select ovarian cancer patients who will benefit from a new class of drugs called “PARP inhibitors.”

U.K. researchers have developed a new test that could be used to select which patients with ovarian cancer will benefit from a new class of drugs called “PARP (poly (ADP-ribose) polymerase) inhibitors,” according to preclinical research presented at the National Cancer Research Institute (NCRI) Cancer Conference held in Liverpool on November 8th.  According to the test results, approximately 50 percent of all patients with ovarian cancer may benefit from PARP inhibitors.

Dr. Asima Mukhopadhyay Discusses Her Research Into A More Tailored Treatment For Ovarian Cancer

PARP Inhibition & BRCA Gene Mutations: Exploiting Ovarian Cancer’s Inherent Defects

  • Genetics 101

DNA (deoxyribonucleic acid) is the genetic material that contains the instructions used in the development and functioning of our cells. DNA is generally stored in the nucleus of our cells. The primary purpose of DNA molecules is the long-term storage of information. Often compared to a recipe or a code, DNA is a set of blueprints that contains the instructions our cells require to construct other cell components, such as proteins and RNA (ribonucleic acid) molecules. The DNA segments that carry this genetic information are called “genes.”

A gene is essentially a sentence made up of the bases A (adenine), T (thymine), G (guanine), and C (cytosine) that describes how to make a protein. Any change in the sequence of bases — and therefore in the protein instructions — is a mutation. Just like changing a letter in a sentence can change the sentence’s meaning, a mutation can change the instruction contained in the gene. Any changes to those instructions can alter the gene’s meaning and change the protein that is made, or how or when a cell makes that protein.

Gene mutations can (i) result in a protein that cannot carry out its normal function in the cell, (ii) prevent the protein from being made at all, or (iii) cause too much or too little of a normal protein to be made.

  • Targeting DNA Repair Through PARP Inhibition

Targeting DNA repair through PARP inhibition in BRCA gene-mutated cancer cells. "DSB" stands for DNA "Double Stand Break." (Photo Credit: AstraZeneca Oncology)

Normally functioning BRCA1 and BRCA2 genes are necessary for DNA repair through a process known as “homologous recombination” (HR).  HR is a form of genetic recombination in which two similar DNA strands exchange genetic material. This process is critical to a cell’s ability to repair its DNA in the event that it becomes damaged, so the cell can continue to function.

A cell’s DNA structure can be damaged by a wide variety of intentional (i.e., select cancer treatments) or unintentional (ultraviolet light, ionizing radiation, man-made chemicals, etc.) factors.  For example, chemotherapy regimens used in the treatment of cancer, including alkylating agents, topoisomerase inhibitors, and platinum drugs, are designed to damage DNA and prevent cancer cells from reproducing.

In approximately 10 percent of inherited ovarian cancers, the BRCA 1 or BRCA2 gene is damaged or mutated.  When the BRCA1 or BRCA2 gene is mutated, a backup type of DNA repair mechanism called “base-excision repair” usually compensates for the lack of DNA repair by HR.  Base-excision repair represents a DNA “emergency repair kit.” DNA repair enzymes such as PARP, whose activity and expression are upregulated in tumor cells, are believed to dampen the intended effect of chemotherapy and generate drug resistance.

When the PARP1 protein – which is necessary for base-excision repair – is inhibited in ovarian cancer cells possessing a BRCA gene mutation, DNA repair is drastically reduced, and the cancer cell dies through so-called “synthetic lethality.”  In sum, PARP inhibitors enhance the potential of chemotherapy (and radiation therapy) to induce cell death.  Healthy cells are unaffected if PARP is blocked because they either contain one or two working BRCA1 or BRCA2 genes which do an effective DNA repair job through use of HR.

  • PARP Inhibitors: A New Class of Targeted Therapy

PARP inhibitors represent a new, targeted approach to treating certain types of cancers. PARP inhibition has the potential to overwhelm cancer cells with lethal DNA damage by exploiting impaired DNA repair function inherent in some cancers, including breast and ovarian cancers with defects in the BRCA1 gene or BRCA 2 gene, and other DNA repair molecules. Inhibition of PARP leads to the cell’s failure to repair single strand DNA breaks, which, in turn, causes double strand DNA breaks. These effects are particularly detrimental to cancer cells that are deficient in repairing double strand DNA breaks and ultimately lead to cancer cell death.

PARP inhibitors are the first targeted treatment to be developed for women with inherited forms of breast and ovarian cancer carrying faults or mutations in a BRCA gene. Early results from clinical trials are showing promise for patients with the rare inherited forms of these cancers.

Study Hypothesis: PARP Inhibitors May Be Effective Against a Large Proportion of Non-Inherited Ovarian Cancers

As noted above, PARP inhibitors selectively target HR–defective cells and have shown good clinical activity in hereditary breast and ovarian cancers associated with BRCA1 or BRCA2 mutations. The U.K. researchers hypothesized that a high proportion (up to 50%) of sporadic (non-inherited) epithelial ovarian cancers could be deficient in HR due to genetic or epigenetic inactivation of the BRCA1, BRCA2, or other HR-related genes, which occur during a woman’s lifetime. Therefore, PARP inhibitors could prove beneficial to a larger group of ovarian cancer patients, assuming a patient’s HR status can be properly identified.

To test this hypothesis, the U.K. researchers developed a functional assay to test the HR status of primary ovarian cancer cultures derived from patients’ ascitic fluid. The test, referred to as the “RAD51 assay,” scans the cancer cells and identifies which tumor samples contain defective DNA repair ability (i.e., HR-deficient) which can be targeted by the PARP inhibitor. The researchers tested the HR status of each culture, and then subjected each one to in vitro cytotoxicity testing using the potent PARP inhibitor PF-01367338 (formerly known as AG-14699).

Study Results: 90% of HR-Deficient Ovarian Cancer Cultures Respond to PARP Inhibition

Upon testing completion, the U.K. researchers discovered that out of 50 primary cultures evaluated for HR status and cytotoxicity to the PARP inhibitor, approximately 40% of the cultures evidenced normal HR activity, while 60 percent of the cultures evidenced deficient HR activity. Cytotoxicity to PARP inhibitors was observed in approximately 90 percent of the HR deficient cultures, while no cytotoxicity was seen in the cultures that evidenced normal HR activity. Specifically, the PARP inhibitor PF-01367338 was found to selectively block the spread of ovarian tumor cells with low RAD51 expression.

Conclusion

Based upon the findings above, the U.K. researchers concluded that HR-deficient status can be determined in primary ovarian cancer, and that such status correlates with in vitro response to PARP inhibition.  Accordingly, the researchers concluded that potentially 50 to 60 percent of ovarian cancers could benefit from PARP inhibitors, but they note that use of the RAD51 assay as a biomarker requires additional clinical trial testing.  Although the RAD51 assay test that was used by the U.K. researchers to examine tumor samples in the laboratory is not yet suitable for routine clinical practice, the U.K. research team hopes to refine it for use in patients.

Upon presentation of the testing results, Dr. Asima Mukhopadhyay said:

“Our results show that this new test is almost 100 percent effective in identifying which ovarian cancer patients could benefit from these promising new drugs.  We have only been able to carry out this work because of the great team we have here which includes both doctors and scientists.”

The team based at Queen Elizabeth Hospital, Gateshead and the Newcastle Cancer Centre at the NICR, Newcastle University collaborated with Pfizer to develop the new assay to test tumor samples taken from ovarian cancer patients when they had surgery.

Dr. Mukhopadhyay added:

“Now we hope to hone the test to be used directly with patients and then carry out clinical trials. If the trials are successful we hope it will help doctors treat patients in a personalised and targeted way based on their individual tumour. It is also now hoped that PARP inhibitors will be useful for a broad range of cancers and we hope this test can be extended to other cancer types.”

Dr. Lesley Walker, Cancer Research UK’s director of cancer information, said:

“It’s exciting to see the development of promising new ‘smart’ drugs such as PARP inhibitors. But equally important is the need to identify exactly which sub-groups of patients will benefit from these new treatments. Tests like this will become invaluable in helping doctors get the most effective treatments quickly to patients, sparing them from unnecessary treatments and side effects.”

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Additional Information:

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About The Researchers

Dr. Asima Mukhopadhyay is a doctor and clinical research fellow working at the Queen Elizabeth Hospital, Gateshead and the Northern Institute for Cancer Research at Newcastle University. Queen Elizabeth Hospital is run by Gateshead Health NHS Foundation Trust and is the home for gynecological oncology for the North East of England and Cumbria. She received a bursary to attend the conference, which was awarded on the merit of her work.

Key researchers on the study included Dr. Richard Edmondson, who was funded by the NHS, and Professor Nicola Curtin, who was funded by the Higher Education Funding Council. Dr Asima Mukhopadhyay is funded by the NHS.

Dr Richard Edmondson is a consultant gynecological oncologist at the Northern Gynaecological Oncology Centre, Gateshead and a Senior Lecturer at the Newcastle Cancer Centre at the Northern Institute for Cancer Research, Newcastle University, and is a member of the research team.

Nicola Curtin is Professor of Experimental Cancer Therapeutics at Newcastle University and is the principal investigator of this project.

Current and future work involves working closely with Pfizer. Pfizer developed one of the PARP inhibitors and supported this project.

About The Newcastle Cancer Centre

The Newcastle Cancer Centre at the Northern Institute for Cancer Research is jointly funded by three charities: Cancer Research UK, Leukaemia and Lymphoma Research, and the North of England Children’s Cancer Research Fund.  Launched in July 2009, the Centre is based at the Northern Institute for Cancer Research at Newcastle University.  The Centre brings together some of the world’s leading figures in cancer research and drug development. They play a crucial role in delivering the new generation of cancer treatments for children and adults by identifying new drug targets, developing new drugs and verifying the effectiveness and safety of new treatments. This collaborative approach makes it easier for researchers to work alongside doctors treating patients, allowing promising new treatments to reach patients quickly.

About the NCRI Cancer Conference

The National Cancer Research Institute (NCRI) Cancer Conference is the UK’s major forum for showcasing the best British and international cancer research. The Conference offers unique opportunities for networking and sharing knowledge by bringing together world leading experts from all cancer research disciplines. The sixth annual NCRI Cancer Conference was held from November 7-10, 2010 at the BT Convention Centre in Liverpool. For more information visit www.ncri.org.uk/ncriconference.

About the NCRI

The National Cancer Research Institute (NCRI) was established in April 2001. It is a UK-wide partnership between the government, charity and industry which promotes cooperation in cancer research among the 21 member organizations for the benefit of patients, the public and the scientific community. For more information visit www.ncri.org.uk.

NCRI members include: the Association of the British Pharmaceutical Industry (ABPI); Association for International Cancer Research; Biotechnology and Biological Sciences Research Council; Breakthrough Breast Cancer; Breast Cancer Campaign; CancerResearch UK; CHILDREN with LEUKAEMIA, Department of Health; Economic and Social Research Council; Leukaemia & Lymphoma Research; Ludwig Institute for Cancer Research; Macmillan Cancer Support; Marie Curie Cancer Care; Medical Research Council; Northern Ireland Health and Social Care (Research & Development Office); Roy Castle Lung Cancer Foundation; Scottish Government Health Directorates (Chief Scientist Office);Tenovus; Welsh Assembly Government (Wales Office of Research and Development for Health & Social Care); The Wellcome Trust; and Yorkshire Cancer Research.

Researchers Identify “Missing Link” Underlying DNA Repair & Platinum Drug Resistance

Researchers have discovered an enzyme crucial to a type of DNA repair that also causes resistance to a class of cancer drugs most commonly used against ovarian cancer.

Scientists from The University of Texas MD Anderson Cancer Center and the Life Sciences Institute of Zhejiang University in China report the discovery of the enzyme and its role in repairing DNA damage called “cross-linking” in the Science Express advance online publication of Science.

Junjie Chen, Ph.D., Professor and Chair, Department of Experimental Radiation Oncology, University of Texas M.D. Anderson Cancer Center

“This pathway that repairs cross-linking damage is a common factor in a variety of cancers, including breast cancer and especially in ovarian cancer. If the pathway is active, it undoes the therapeutic effect of cisplatin and similar therapies,” said co-corresponding author Junjie Chen, Ph.D., professor and chair of MD Anderson’s Department of Experimental Radiation Oncology.

The platinum-based chemotherapies such as cisplatin, carboplatin and oxaliplatin work by causing DNA cross-linking in cancer cells, which blocks their ability to divide and leads to cell death. Cross-linking occurs when one of the two strands of DNA in a cell branches out and links to the other strand.

Cisplatin and similar drugs are often initially effective against ovarian cancer, Chen said, but over time the disease becomes resistant and progresses.

Scientists have known that the protein complex known as FANCIFANCD2 responds to DNA damage and repairs cross-linking, but the details of how the complex works have been unknown. “The breakthrough in this research is that we finally found an enzyme involved in the repair process,” Chen said.

The enzyme, which they named FAN1, appears to be a nuclease, which is capable of slicing through strands of DNA.

In a series of experiments, Chen and colleagues demonstrated how the protein complex summons FAN1, connects with the enzyme and moves it to the site of DNA cross-linking. They also showed that FAN1 cleaves branched DNA but leaves the normal, separate double-stranded DNA alone. Mutant versions of FAN1 were unable to slice branched DNA.

Like a lock and key

The researchers also demonstrated that FAN1 cannot get at DNA damage without being taken there by the FANCI-FANCD2 protein complex, which detects and moves to the damaged site. The complex recruits the FAN1 enzyme by acquiring a single ubiquitin molecule. FAN1 connects with the complex by binding to the ubiquitin site.

“It’s like a lock and key system, once they fit, FAN1 is recruited,” Chen said.

Analyzing the activity of this repair pathway could guide treatment for cancer patients, Chen said, with the platinum-based therapies used when the cross-linking repair mechanism is less active.

Scientists had shown previously that DNA repair was much less efficient when FANCI and FANCD2 lack the single ubiquitin. DNA response and damage-repair proteins can be recruited to damage sites by the proteins’ ubiquitin-binding domains. The team first identified a protein that had both a ubiquitin-binding domain and a known nuclease domain. When they treated cells with mitomycin C, which promotes DNA cross-linking, that protein, then known as KIAA1018, gathered at damage sites. This led them to the functional experiments that established its role in DNA repair.

They renamed the protein FAN1, short for Fanconi anemia-associated nuclease 1. The FANCI-FANCD2 complex is ubiquitinated by an Fanconi anemia (FA) core complex containing eight FA proteins. These genes and proteins were discovered during research of FA, a rare disease caused by mutations in 13 fanc genes that is characterized by congenital malformations, bone marrow failure, cancer and hypersensitivity to DNA cross-linking agents.

Chen said the FANCI-FANCD2 pathway also is associated with the BRCA1 and BRCA2 pathways, which are involved in homologous recombination repair. Scientists know that homologous recombination repair is also required for the repair of DNA cross-links, but the exact details remain to be resolved, Chen said. Mutations to BRCA1 and BRCA2 are known to raise a woman’s risk for ovarian and breast cancers and are found in about 5-10 percent of women with either disease.

Co-authors with Chen are co-first author Gargi Ghosal, Ph.D., and Jingsong Yuan, Ph.D., also of Experimental Radiation Oncology at MD Anderson; and co-corresponding author Jun Huang, Ph.D., co-first author Ting Liu, Ph.D., of the Life Sciences Institute of Zhejiang University in Hangzhou, China.

This research was funded by a grant from the U.S. National Institutes of Health and the Startup Fund at Zhejiang University.

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PARP Inhibitor Olaparib Benefits Women With Inherited Ovarian Cancer Based Upon Platinum Drug Sensitivity

Olaparib (AZD2281), a new type of cancer drug known as a “PARP inhibitor,” produced promising results in patients with platinum-refractory, platinum-resistant, and platinum-sensitive ovarian cancer linked to an inherited BRCA1 or BRCA2 gene mutation.

A new type of cancer drug — known as a “PARP inhibitor” — produced promising results in patients with ovarian cancer linked to an inherited BRCA1 or BRCA2 gene mutation. The trial results were published online in the Journal of Clinical Oncology on April 19th.

Scientists at The Institute of Cancer Research (ICR) and The Royal Marsden Hospital, working with pharmaceutical company KuDOS Pharmaceuticals, now a subsidiary of AstraZeneca, found the experimental drug olaparib shrank or stabilized tumors in approximately half of ovarian cancer patients possessing BRCA1 or BRCA2 mutations.

The five-year survival rate for ovarian cancer is just 40 per cent as the majority of patients are diagnosed with an advanced form of the disease. Most patients initially respond well to radical surgery and platinum and taxane-based chemotherapy, but relapse after an average of 18 months. Subsequent treatments generally become less effective as patients build up resistance.

Professor Stan Kaye, Head of Section of Medicine, Institute of Cancer Research; Head of Drug Development Unit, The Royal Marsden Hospital; and Cancer Research UK-funded scientist

“There is an urgent need to find new drugs for women diagnosed with ovarian cancer,” says Professor Stan Kaye, Head of the Section of Medicine at the ICR and Head of the Drug Development Unit at The Royal Marsden Hospital and a Cancer Research UK-funded scientist. “Olaparib is still in early-stage testing but the results so far are very encouraging. These findings raise the possibility that carefully selected patients in future may well be offered olaparib as an alternative to chemotherapy during the course of their treatment.”

Between 2005 and 2008, about 50 women with confirmed or suspected BRCA1 or BRCA2 mutations began treatment with olaparib in a dose escalation and single-stage expansion of a Phase I trial. Twenty patients responded with their tumors shrinking or with significant falls in their ovarian cancer marker CA125, or both. The disease also stabilized in three patients. The drug was effective for an average of seven months. Notably, several patients are still taking olaparib (for nearly two years). Drug side-effects were generally mild, especially when compared to current chemotherapy treatments.

Olaparib is a new type of drug known as a PARP inhibitor that works by turning a tumor’s specific genetic defect against itself. In susceptible cells, olaparib prevents the repair of naturally occurring breaks in DNA, which healthy cells are able to repair. Susceptible cancer cells – those with an existing defect in a DNA repair pathway caused by a mutation in the BRCA1 or BRCA2 genes – are unable to repair themselves, and therefore, die.

Platinum-based chemotherapy, particularly carboplatin, is one of the main treatments used for ovarian cancer. When this treatment ceases to be effective, theoretically, olaparib might be less effective too, so the ICR scientists examined whether olaparib would still benefit patients whose response to previous platinum-based drugs was limited. Finding new drugs to treat these “platinum-resistant” ovarian cancer patients (those who relapsed within six months of previous platinum therapy) is a particularly high priority as they have a lower chance of benefiting from re-treatment with chemotherapy and a poorer prognosis.

The research team found that the clinical benefit rate with olaparib was indeed higher — 70% — among patients with “platinum-sensitive disease” (disease recurrence more than six months after previous platinum therapy). Crucially, however, the clinical benefit rate was still 46% in platinum resistant patients.

ICR Study Findings:

  • 50 patients participated in the study (13 had platinum-sensitive disease, 24 had platinum-resistant disease, and 13 had platinum-refractory disease (according to platinum-free interval).
  • 20 patients (40%) achieved complete or partial responses under RECIST (Response Evaluation Criteria in Solid Tumors) criteria and/or tumor marker (CA125) responses.
  • Overall clinical benefit rate (complete response + partial response + stable disease) = 46%.
  • Median response duration was 28 weeks.
  • There was a significant association between the clinical benefit rate and platinum-free interval across the platinum-sensitive, resistant, and refractory patient subgroups (69%, 45%, and 23%, respectively).
  • Analyses indicated associations between platinum sensitivity and extent of olaparib response.
  • CONCLUSION: Olaparib has antitumor activity in BRCA1/2 mutation ovarian cancer, which is associated with platinum sensitivity.

Up to 15 per cent of breast and ovarian cancers have known BRCA1 or BRCA2 mutations on blood testing and, importantly, laboratory data strongly suggests that olaparib may also be effective in cancers linked to DNA repair defects not caused by BRCA1 and BRCA2 mutations. This could apply in about half the cases of the most common histological type of ovarian cancer.

“We have good reason for thinking that the benefit seen with olaparib in BRCA mutation-linked ovarian cancer may well extend to a broader population of patients with this disease,” says Professor Kaye.

Randomised trials of olaparib – in which some patients receive the drug and others a placebo – are underway and results will be available later this year.

KuDOS Pharmaceuticals (a wholly owned subsidiary of AstraZeneca) was the major funder of the trial, along with Cancer Research UK and the National Institute for Health Research. Olaparib was identified and developed at KuDOS Pharmaceuticals and subsequently at AstraZeneca.

PARP Inhibitor Clinical Trials:

To view a list of open ovarian cancer clinical trials that are testing olaparib (AZD2281), click here.

To view a list of open solid tumor clinical trials that are testing olaparib (AZD2281), click here.

To view a list of open ovarian cancer clinical trials that are testing various PARP inhibitors, click here.

To view a list of open solid tumor clinical trials that are testing various PARP inhibitors, click here.

About The Institute of Cancer Research (ICR)

* The ICR is Europe’s leading cancer research centre.

* The ICR has been ranked the UK’s top academic research centre, based on the results of the Higher Education Funding Council’s Research Assessment Exercise.

* The ICR works closely with partner The Royal Marsden NHS Foundation Trust to ensure patients immediately benefit from new research. Together the two organisations form the largest comprehensive cancer centre in Europe.

* The ICR has charitable status and relies on voluntary income, spending 95 pence in every pound of total income directly on research.

* As a college of the University of London, the ICR also provides postgraduate higher education of international distinction.

* Over its 100-year history, the ICR’s achievements include identifying the potential link between smoking and lung cancer which was subsequently confirmed, discovering that DNA damage is the basic cause of cancer and isolating more cancer-related genes than any other organization in the world.

* The ICR is home to the world’s leading academic drug development team. Several important anti-cancer drugs used worldwide were synthesised at the ICR and it has discovered an average of two preclinical candidates each year over the past five years.

For more information visit www.icr.ac.uk.

About The Royal Marsden Hospital

The Royal Marsden opened its doors in 1851 as the world’s first hospital dedicated to cancer treatment, research and education. Today, together with its academic partner, The Institute of Cancer Research, it is the largest and most comprehensive cancer centre in Europe treating over 40,000 patients every year. It is a centre of excellence, and the only NHS Trust to achieve the highest possible ranking in the Healthcare Commission’s Annual Health Check for the third year in a row. Since 2004, the hospital’s charity, The Royal Marsden Cancer Campaign, has helped raise over £43 million to build theatres, diagnostic centres, and drug development units. Prince William became President of The Royal Marsden in 2007, following a long royal connection with the hospital.

For more information, visit www.royalmarsden.nhs.uk

About Cancer Research UK

* Cancer Research UK is the world’s leading charity dedicated to beating cancer through research.

* The charity’s groundbreaking work into the prevention, diagnosis and treatment of cancer has helped save millions of lives. This work is funded entirely by the public.

* Cancer Research UK has been at the heart of the progress that has already seen survival rates double in the last thirty years.

* Cancer Research UK supports research into all aspects of cancer through the work of more than 4,800 scientists, doctors and nurses.

* Together with its partners and supporters, Cancer Research UK’s vision is to beat cancer.

For further information about Cancer Research UK’s work or to find out how to support the charity, please call 020 7121 6699 or visit www.cancerresearchuk.org

About Experimental Cancer Medicine Centre (ECMC)

Experimental Cancer Medicine Centre (ECMC) status has been awarded to 19 centres in the UK that are specialist centres conducting research into new cancer treatments. The aim is to bring together cancer doctors, research nurses and lab scientists to make clinical trials of new treatments quicker and easier. The ECMC initiative is funded by Cancer Research UK and the Departments of Health of England, Scotland, Wales and Northern Ireland. Together they are giving a total of £35 million pounds over five years to the 19 centres. The centres will use this money to run trials of new and experimental treatments. They will also analyse thousands of blood and tissue samples (biopsies) to help find out more about how treatments work and what happens to cancer cells.

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Increased Ovarian Cancer Metastases Identified In Women With BRCA Gene Mutations; May Shed Light on New Treatment Approach

U.K. researchers have found that patients with hereditary ovarian cancer – whose tumors are caused by faulty BRCA1 or BRCA2 genes – are more likely to experience metastases of the liver, lung, spleen, and viscera. … [T]he researchers suggest that ovarian cancer patients whose tumors spread to the solid organs … should be tested for the faulty genes – BRCA1 and BRCA2 – to ensure they are given the most appropriate treatment.

Dr. Charlie Gourley, Acting Head, Medical Oncology, University of Edinburgh Cancer Research Centre

U.K. researchers have found that patients with hereditary ovarian cancer – whose tumors are caused by faulty BRCA1 or BRCA2 genes – are more likely to experience metastases of the liver, lungs, spleen, and viscera. This is despite the fact that their overall prognosis is better than other ovarian cancer patients.  The research is published in the April 20th online edition of the Journal of Clinical Oncology.

In the study, researchers discovered that the percentage of women with BRCA1 or BRCA2 gene mutations who experienced visceral, liver, lung, and splenic metastases were 58%, 42%, 16%, and 32% , respectively, as compared with 5%, 0%, 0%, and 3%, respectively, in non-BRCA gene deficient women.  The researchers note that sporadic (i.e., non-hereditary) ovarian tumors tend to remain within the lining of the abdomen and pelvis.

Based upon the study findings, the researchers suggest that ovarian cancer patients whose tumors spread to the solid organs such as the liver, lungs, and spleen should be tested for the faulty genes – BRCA1 and BRCA2 – to ensure they are given the most appropriate treatment.  For example, patients with hereditary tumors, which account for 10 per cent of ovarian cancers, may be suitable for trials of a new drug called olaparib [AZD2281], which has fewer side-effects than normal cancer treatments. Olaparib belongs to a class of drugs known as “PARP” (Poly (ADP-ribose) polymerase) inhibitors.

Researchers say the study findings will improve the detection of faulty BRCA genes, as current criteria for genetic testing may miss as many as two-thirds of ovarian cancer patients carrying the mutated genes.  Improving the identification of BRCA mutations will help relatives of ovarian cancer patients, who may themselves be at increased risk of developing hereditary ovarian cancer.

Dr. Charlie Gourley, who led the research at the University of Edinburgh, said:

“We are beginning to understand the importance of tailoring cancer treatments according to the specifics of each patient’s tumor. These findings demonstrate that tumors which arise because of defects in the BRCA1 or BRCA2 genes behave differently to other ovarian cancers. This information should also help us to identify the patients carrying these genetic mutations, give them the most effective treatment for their cancer and offer their relatives genetic counselling.”

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UA Research Team Designing Holographic Imaging System For Ovarian Cancer

University of Arizona researchers Jennifer Barton and Ray Kostuk have received a five-year, $2.4 million grant from the National Institutes of Health to build the instrument that they hope will one day be used to monitor women at high risk for ovarian cancer.

Hologram of Human Ovary

Human ovary image captured with the use of the prototype holographic imaging system the team developed. (Photo: Univ. of Arizona News)

Hologram of An Orange

For comparison, an onion is imaged with the use of the prototype system the team developed. (Photo: Univ. of Arizona News)

Two University of Arizona [UA] researchers have formed a research team to design, build and evaluate two versions of an ovarian cancer medical imaging and screening instrument that will use holographic components in a new type of optical microscope.

Raymond Kostuk and Jennifer Barton have secured a five-year, $2.4 million grant from the National Institutes of Health to build the instrument that they hope will one day be used to monitor women at high risk for ovarian cancer. Kostuk is the Kenneth Von Behren Professor of Electrical and Computer Engineering and professor of optical sciences. Barton heads the UA department of biomedical engineering and is assistant director of the BIO5 Institute.

The system is unique in that it will for the first time project multiple spatial images from different depths within a tissue sample and simultaneously provide spectral information from optical markers in order to better identify cancerous cells.

This combined spectral spatial imaging technique shows potential to be much more effective in identifying cancerous tissue sites than by separately using spatial or spectral information.

The grant was issued following the successful two-year development of a prototype system the team built. It tests the validity of using holographic technology for subsurface imaging without having to perform surgery and take tissue samples.

According to the National Institutes of Health, there is, to date, no single effective screening test for ovarian cancer, so ovarian cancer is rarely diagnosed in its early stages. The result is that in more than 50 percent of women with ovarian cancer are diagnosed in the late stages of the disease when the cancer has already advanced.

  • About 76 percent percent of women with ovarian cancer survive one year after diagnosis.
  • About 45 percent live longer than 5 years after diagnosis.

Barton said ovarian cancer provides a compelling case to test holographic imaging and its efficacy in detecting cancers. At the present time the preferred treatment is surgery, which is also often needed to diagnose ovarian cancer. The procedure includes taking tissue samples, which may threaten the woman’s ability to have children in the future.

Jennifer Barton, UA

Jennifer Barton, Professor & Chair, Department of Biomedical Engineering; Assistant Director, BIO5 Institute. (Photo: Univ of Arizona News)

“Ovarian cancer has no symptoms until it is highly advanced making the five-year prognosis extremely poor. Those at high risk – with a family history of ovarian cancer or those who carry genetic mutations in the BRCA1 and BRCA2 genes, which normally help protect against both breast and ovarian cancer – may be counseled to have their ovaries removed through laparoscopic surgery,” Barton said. “Now imagine if you are an 18-year-old woman who has this history – ovaries are an important part of your overall health. They produce hormones you need over and above the notion that you would need your ovaries should you want to have children in the future.”

Thus, new technology capable of reliably diagnosing ovarian cancer in earlier stages could reduce the morbidity, high mortality and economic impact of this disease.

The system will work like a high-powered microscope that can be used to study tissue samples already removed. In addition, an endoscopic version is in the design stage to safely scan the ovaries for cancer during laparoscopic screenings in high-risk women, or as an adjunct to other laparoscopic procedures in all women.

The team will work with Dr. Kenneth D. Hatch, president of the Society of Pelvic Surgeons, and a professor of obstetrics and gynecology and director of female pelvic medicine and reconstructive surgery at the UA College of Medicine.

Through Hatch and a partnership with his patients who consent, Barton and Kostuk will be able to identify abnormal spatial and spectral markers of cancerous ovarian tissue.

Ray Kostuk

Ray Kostuk, Kenneth Von Behren Professor of Electrical and Computer Engineering & Professor of Optical Sciences, University of Arizona (Photo: Univ. of Arizona News)

The new imaging system will be tested on high-risk patients who are willing to participate and provide some future benefit to other patients who find themselves in a similar situation, Barton said.

Kostuk and Barton’s aim is to design the imaging system so that it is easy to use, requiring very little training, and also be cost effective.

“The system will image like an MRI or a CT scan but with much higher resolution than an ultrasonic image and will be a lot less expensive than an MRI. As an additional benefit no radiation will be used or exposed to sensitive ovary areas during the cancer screenings,” Kostuk said.

During the past 25 years Kostuk has researched different aspects of holography and holographic materials for use as optical elements.

The holographic imaging system being designed combines an optical technique that creates images capable of detecting subtle tissue microstructure changes. Together with fluorescence spectroscopy methods, the system has demonstrated capability for early cancer detection.

Another member of the team, UA research professor Marek Romanowski, with the UA department of biomedical engineering and the BIO5 Institute, is working on the development of targeted fluorescent dyes that will be used on tissue samples to identify or confirm suspected cancerous areas shown in the spatial image.

The multidisciplinary approach to the design of the hologram-based imaging system is a testament to the complexity of treating cancers.

“One of the advantages of being part of the UA is the ability to interact collaboratively with people in other disciplines,” Kotuk said. “Jennifer is a wonderful colleague who can identify important medical applications for new techniques and is able to bridge the gap between traditional engineering and medicine. Her skill and knowledge is critical to the success of the program,” he said.

“To solve the really interesting problems of today, no one person has all the expertise needed,” Barton added.

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Women Often Opt to Surgically Remove Their Breasts, Ovaries to Reduce Cancer Risk

Many women at high risk for breast or ovarian cancer are choosing to undergo surgery as a precautionary measure to decrease their cancer risk, according to a report in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

PHILADELPHIA – Many women at high risk for breast or ovarian cancer are choosing to undergo surgery as a precautionary measure to decrease their cancer risk, according to a report in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Gareth

Dr. Gareth Evans is an international authority on cancer genetics. Dr. Evans is the Chairman of the National Institute For Health & Clinical Excellence (NICE) familial breast cancer group; Chairman, Cancer Genetics Group & Council Member, British Society of Human Genetics; Consultant, Genesis Prevention Center, Univ. Hospital of South Manchester NHS Trust; Professor, Univ. of Manchester, UK

“Women have their breasts or ovaries removed based on their risk.

Claudine_2009_July_(photo_credit_Phil_Humnicky,_Georgetown)

Dr. Claudine Isaacs is an Associate Professor of Medicine, Director of the Familial Cancer Registry Shared Resource, Director of the Clinical Breast Cancer Program, and the Co-Medical Director of the Fisher Center for Familial Cancer Research at the Lombardi Comprehensive Cancer Center, Georgetown Univ., Washington, D.C. (photo credit: Phil Humnicky, Georgetown Univ.)

It does not always happen immediately after counseling or a genetic test result and can take more than seven years for patients to decide to go forward with surgery,” said lead researcher D. Gareth Evans, M.D. Evans is a consultant in clinical genetics at the Genesis Prevention Center, University Hospital of South Manchester NHS Trust and a professor at the University of Manchester, United Kingdom.

Evans and colleagues assessed the increase in risk-reduction surgery among women with breast cancer and evaluated the impact of cancer risk, timing and age.

Rate of increase was measured among 211 women with known unaffected BRCA1 or BRCA2 mutation carriers. BRCA1 and BRCA2 are hereditary gene mutations that indicate an increased risk for developing breast cancer. Additionally, more than 3,500 women at greater than 25 percent lifetime risk of breast cancer without mutations also had a documented increase in risk-reduction surgery.

Women who had a biopsy after undergoing risk evaluation were twice as likely to choose a risk-reducing mastectomy. Forty percent of the women who were mutation carriers underwent bilateral risk-reducing mastectomy; 45 percent had bilateral risk-reducing salpingo-oophorectomy (surgical removal of ovaries). These surgeries are widely used by carriers of BRCA1 and BRCA2 gene mutations to reduce the risk for breast and ovarian cancer.

Evaluated by gene type, bilateral risk-reducing salpingo-oophorectomy was more common in women who were BRCA1 gene carriers – 52 percent had the surgery compared with 28 percent of the women who were BRCA2 gene carriers.

“We found that older women were much less likely to have a mastectomy, but were more likely to have their ovaries removed,” said Evans.

Most of the women, specifically those aged 35 to 45 years, opted for surgery within the first two years after the genetic mutation test, but some did not make a decision until seven years later.

“This is a very interesting study. It fleshes out some of what we know about adoption of risk reduction strategies in high-risk women who have participated in a very comprehensive and well thought-out genetic counseling, testing and management program,” said Claudine Isaacs, M.D., an associate professor of medicine and co-director of the Fisher Center for Familial Cancer Research, Lombardi Comprehensive Cancer Center at Georgetown University.

BRCA1 and BRCA2 mutation carriers have a very high lifetime risk of cancer, and for BRCA1 carriers there are unfortunately no clearly proven non-surgical prevention strategies, according to Isaacs. These women face a 50 to 85 percent lifetime risk of breast cancer, and mastectomy is currently the most effective prevention method available.

The findings confirm the expectations that when a woman has a biopsy, even if benign, most are more likely to opt for risk-reduction surgery.

“Screening should be conducted at a place with expertise in an effort to minimize false-positive results, which often lead to biopsy. This will minimize the anxiety that comes along with such a diagnosis. Patients should consult with an expert in advance and stay in contact with them to see how the science may be changing over time,” she advised. “This is an ongoing conversation that needs to be addressed and individualized for each patient.”

Likewise, Evans suggested that additional studies are needed to help evaluate the communication efforts and methods between doctors and/or counselors and women at risk for breast cancer. Questions to be raised should include how is the communication method occurring, are the doctors sympathetic and is there an ongoing dialogue?

“Careful risk counseling does appear to influence women’s decision for surgery although the effect is not immediate,” the researchers wrote.

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Beyond BRCA1 & BRCA2: U.K. Researchers Identify Genetic Defect That Could Increase Risk of Ovarian Cancer Up To 40%

Scientists have located a region of DNA which – when altered – can increase the risk of ovarian cancer according to research published in Nature Genetics today. An international research group led by scientists based at the Cancer Research UK Genetic Epidemiology Unit, at the University of Cambridge and UCL (University College London) searched through the genomes of 1,810 women with ovarian cancer and 2,535 women without the disease from across the UK. …The scientists estimate that there is a 40 per cent increase in lifetime risk for women carrying the DNA variation on both copies of chromosome nine compared with someone who doesn’t carry it on either chromosome. The risk for women carrying the variation on both chromosomes is 14 in 1000 – compared with [10] ten in 1000 [in the general population]. … The lifetime risk for a woman carrying the DNA variant on one copy of the chromosome is increased by 20 per cent from ten in 1000 to 12 in 1000. …

Genetic link to ovarian cancer found

Cancer Research UK

SUNDAY 2 AUGUST 2009

Cancer Research UK Press Release

Scientists have located a region of DNA which – when altered – can increase the risk of ovarian cancer according to research published in Nature Genetics today.

An international research group led by scientists based at the Cancer Research UK Genetic Epidemiology Unit, at the University of Cambridge and UCL (University College London) searched through the genomes of 1,810 women with ovarian cancer and 2,535 women without the disease from across the UK. They analysed 2.5 million variations in DNA base pairs – the letters which spell out the genetic code – to identify common spelling ‘errors’ linked to ovarian cancer risk.

The scientists identified the genetic ‘letters’- called single nucleotide polymorphisms (SNPs) – which when spelled slightly differently increase ovarian cancer risk in some women. This is the first time scientists have found a SNP linked uniquely to risk of ovarian cancer and is the result of eight years of investigations. With the help of the international Ovarian Cancer Association Consortium (OCAC), they then looked at more than 7,000 additional women with ovarian cancer and 10,000 women without disease from around the world to confirm this finding.

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The region of risk DNA is located on chromosome nine – there are 23 pairs of each chromosome in humans, one of each pair inherited from each parent. The scientists estimate that there is a 40 per cent increase in lifetime risk for women carrying the DNA variation on both copies of chromosome nine compared with someone who doesn’t carry it on either chromosome. The risk for women carrying the variation on both chromosomes is 14 in 1000 – compared with [10] ten in 1000 [in the general population].

Approximately 15 per cent of women in the UK population carry two copies of the variant DNA.

The lifetime risk for a woman carrying the DNA variant on one copy of the chromosome is increased by 20 per cent from ten in 1000 to 12 in 1000. Approximately 40 per cent of women in the UK carry one copy.

Senior author Dr. Simon Gayther, whose work is supported by Cancer Research UK and The Eve Appeal charity which fundraises for the gynaecological cancer research team based at UCL, said: “The human DNA blueprint contains more than 10 million genetic variants. These are part and parcel of our characteristics and make-up – but a handful will also increase the chances of some women getting ovarian cancer and we have found the first one of these.”

“There is now a genuine hope that as we find more, we can start to identify the women at greatest risk and this could help doctors to diagnose the disease earlier when treatment has a better chance of being successful.”

Dr. Andrew Berchuck, head of the international Ovarian Cancer Association Consortium steering committee, said: “This study confirms that ovarian cancer risk is partly determined by genetic variants present in a large number of women. This initial discovery and others that will likely follow in the future lay the groundwork for individualised early detection and prevention approaches to reduce deaths from ovarian cancer.”

Ovarian cancer is the fifth most common cancer in women in the UK with around 6,800 new cases diagnosed each year in the UK – 130 women every week. It is the fourth most common cause of cancer death in women in the UK with around 4,300 deaths from the disease in the UK each year.

BRCA1 and BRCA2 are high risk genes which cause breast cancer and are already known to significantly increase the risk of ovarian cancer- but faults in these genes are rare and probably cause less than five per cent of all cases of ovarian cancer.

Lead author, Professor Dr Paul Pharoah, a Cancer Research UK senior research fellow at the University of Cambridge, said: “We already know that people with mistakes in the BRCA1 and BRAC2 genes have a greater risk of ovarian cancer – but on their own they don’t account for all of the inherited risk of the disease. “It is likely that the remaining risk is due to a combination of several unidentified genes – which individually carry a low to moderate risk. Now we have ticked one off, the hunt is on to find the rest.”

Rose Lammy, the mother of David Lammy MP [Member of Parliament] for Tottenham and Minister for Higher Education and Intellectual Property, died of ovarian cancer in 2008. Rose Lammy’s DNA sample was included in the study, and she carried both risk alleles of the new genetic marker that researchers have identified.

David Lammy said: “I am pleased that Mum’s sample was included in this study as it is one step towards earlier diagnosis of ovarian cancer when treatment is more successful. We now know the fact that she had this altered DNA meant that her lifetime risk had risen from 10 in 1,000 to 14 in 1,000, an increase of 40 per cent compared to those women who don’t carry this DNA variation. Dr Lesley Walker, director of cancer information at Cancer Research UK, added: “This is an important discovery. Our researchers have worked as part of a huge collaboration to establish the regions of DNA that can increase someone’s risk of developing ovarian cancer. “This research paves the way for scientists to discover even more genes linked to ovarian cancer and could lead to new approaches to treat or prevent the disease – crucially it will help doctors manage women who are at increased risk.”

Source: Genetic link to ovarian cancer found, Cancer Research U.K. Press Release & Video, 02 Aug. 09.

Reference: Honglin Song et al. (2009). A genome-wide association study identifies a new ovarian cancer susceptibility locus on 9p22.2 Nature Genetics 10.1038/ng.424.