ASCO 2011: Genetic Biomarker Predicts Taxane Drug-Induced Neuropathy

A new study has identified the first genetic biomarkers for taxane-induced peripheral neuropathy, a potentially severe complication of taxane chemotherapy that affects nerves in about one-third of patients with cancer receiving such treatment.

ASCO Releases Studies From Upcoming Annual Meeting – Important Advances in Targeted Therapies, Screening, and Personalized Medicine

The American Society of Clinical Oncology (ASCO) today highlighted several studies in a press briefing from among more than 4,000 abstracts publicly posted online at http://www.asco.org in advance of ASCO’s 47th Annual Meeting. An additional 17 plenary, late-breaking and other major studies will be released in on-site press conferences at the Annual Meeting.

The meeting, which is expected to draw approximately 30,000 cancer specialists, will be held June 3-7, 2011, at McCormick Place in Chicago, Illinois. The theme of this year’s meeting is “Patients. Pathways. Progress.”

“This year marks the 40th anniversary of the signing of the National Cancer Act, a law that led to major new investments in cancer research. Every day in our offices, and every year at the ASCO meeting, we see the results of those investments. People with cancer are living longer, with a better quality of life, than ever before,” said George W. Sledge Jr., M.D., President of ASCO, Ballve-Lantero Professor of Oncology and professor of pathology and laboratory medicine at the Indiana University School of Medicine.

“With our growing understanding of the nature of cancer development and behavior, cancer is becoming a chronic disease that a growing number of patients can live with for many years,” said Dr. Sledge. “The studies released today are the latest examples of progress against the disease, from new personalized treatments, to new approaches to screening and prevention.”

New study results involving a genetic marker which can predict taxane drug-induced neuropathy were highlighted today in the ASCO press briefing, as summarized below.

Genetic Biomarker Predicts Taxane-Induced Neuropathy

A new study has identified the first genetic biomarkers for taxane drug-induced peripheral neuropathy, a potentially severe complication of taxane chemotherapy that affects nerves in about one-third of patients with cancer receiving such treatment. The finding may eventually lead to a simple blood test to determine whether a patient is at high risk for neuropathy.

Bryan P. Schneider, M.D., Physician & Researcher, Indiana University Melvin & Bren Simon Cancer Center; Associate Director, Indiana Institute for Personalized Medicine

“If these findings can be replicated, this may allow physicians to know prior to recommending therapy whether the patient is at an inordinate risk for developing taxane-induced neuropathy,” said Bryan P. Schneider, M.D., lead author and a physician/researcher at the Indiana University Melvin and Bren Simon Cancer Center and Associate Director for the Indiana Institute for Personalized Medicine. “This may allow for better counseling, use of alternative drugs or schedules, or omission of taxanes in the appropriate settings. These genetic findings might also provide insight into the mechanism of this side effect and help develop drugs to prevent this toxicity altogether.”

Such damage to the nerves can cause pain and numbness and limit the dose of chemotherapy a patient can receive. While only a few factors seem to predict which patients are likely to get peripheral neuropathy, including a history of diabetes and advanced age, genetic variations may explain why some patients are more sensitive to taxane drugs.

The authors conducted a genome wide association study on 2,204 patients enrolled in an Eastern Cooperative Oncology Group breast cancer clinical trial (E5103) in which all patients received taxane-based chemotherapy, namely paclitaxel (Taxol). The study looked for variations in DNA (deoxyribonucleic acid) called single nucleotide polymorphisms, or SNPs (pronounced “snips”), by evaluating more than 1.2 million SNPs in each patient.  A SNP is a DNA sequence variation which occurs when a single nucleotide — A (adenine), T (thymine), C (cytosine), or G (guanine) — in the genome (or other shared sequence) differs between two individuals, or between paired chromosomes located within the nucleus of an individual’s cells.

With a median follow-up of 15 months, the study identified genetic subgroups that were markedly more likely to develop peripheral neuropathy.

Those who carried two normal nucleotides in the RWDD3 gene had a 27 percent chance of experiencing neuropathy; those who carried one normal nucleotide and one SNP had a 40 percent risk; and those who carried two SNPs had a 60 percent risk.

In contrast, those who carried two normal nucleotides in the TECTA gene had a 29 percent chance of experiencing neuropathy; those who carried one normal nucleotide and one SNP had a 32 percent risk; and those who carried two SNPs had a 57 percent risk.

The study also found that older patients and African Americans were much more likely to have peripheral neuropathy, and further analysis of SNPs in these groups is underway.

The authors plan to continue their work in additional trials to validate these findings and to determine whether a different type or schedule of taxane therapy would result in less neuropathy in the more susceptible genetic groups. The authors also are collaborating with neurobiologists to understand why these genetic variations might make the nerves more sensitive to these drugs.

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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.

Genetic Variations In miRNA Processing Pathway & Binding Sites Help Predict Ovarian Cancer Risk

“Genetic variations in the micro-RNA (miRNA) processing pathway genes and miRNA binding sites predict a woman’s risk for developing ovarian cancer and her prospects for survival, researchers from The University of Texas M. D. Anderson Cancer Center reported at the 100th annual meeting of the American Association for Cancer Research. … The unique study was the first to examine the association of genetic variants related to miRNA with ovarian cancer risk, overall survival for ovarian cancer patients, and platinum-based chemotherapy response. …”

Genetic variations in miRNA processing pathway and binding sites help predict ovarian cancer risk – Several variations indicate likelihood of response to platinum-based chemotherapy

DENVER – Genetic variations in the micro-RNA (miRNA) processing pathway genes and miRNA binding sites predict a woman’s risk for developing ovarian cancer and her prospects for survival, researchers from The University of Texas M. D. Anderson Cancer Center reported at the 100th annual meeting of the American Association for Cancer Research.

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Xifeng Wu, M.D., Ph.D., Professor, Department of Epidemiology, The University of Texas M.D. Anderson Cancer Center

‘We found a gene dosage effect, the more unfavorable variations a woman has, the greater her ovarian cancer risk and the shorter her survival time,’ said senior author Xifeng Wu, M.D., Ph.D., professor in M. D. Anderson’s Department of Epidemiology. Median survival, for example, ranged from 151 months for women with fewest unfavorable variations to 24 months for those with the most.

Several variations also indicate likely response to platinum-based chemotherapy.

‘Our findings have the potential clinical application of indicating a patient’s prognosis and showing who will respond to different therapies by analyzing a single blood sample,’ Wu said. ‘We also will incorporate this genetic information with epidemiological information to build a comprehensive model to predict susceptibility to ovarian cancer.’

The team chose the miRNA processing pathway because it is crucial to production of miRNAs, the small molecules that regulate between one third and half of all genes. The researchers also chose the binding sites on host genes where miRNAs exert their effects on gene expression.

They analyzed 219 potential functional single nucleotide polymorphisms (SNPs) – variations of a single DNA building block in a gene – in eight genes that process miRNA and at the miRNA binding sites of 129 cancer-relevant genes. The study examined genetic information from 417 cancer patients and 417 healthy controls. To minimize the possible confounding effects of ethnicity, 339 Caucasian cases and 349 controls were analyzed.

They discovered 12 SNPs to be significantly associated with ovarian cancer risk. Moreover, compared to women with five or fewer unfavorable genotypes, women with eight or more of these unfavorable genotypes were 4.5 times more likely to develop ovarian cancer and women with six to eight unfavorable SNPs were at twice the risk.

The team also found 21 SNPs significantly associated with overall survival. Median survival was 151 months for women with six or fewer unfavorable variations; 42 months for those with seven to nine unfavorable variations; and 24 months for those with 10 or more. One of the outcome risk SNPs also was strongly associated with platinum-based chemotherapy response, with those having the SNP 3.4 times less likely to respond to chemotherapy.

Wu collaborated with Dong Liang, Ph.D, in the College of Pharmacy and Health Sciences, Texas Southern University, and Karen Lu, M.D., professor in M. D. Anderson’s Department of Gynecologic Oncology, on this study.

The unique study was the first to examine the association of genetic variants related to miRNA with ovarian cancer risk, overall survival for ovarian cancer patients, and platinum-based chemotherapy response. Such a wide-ranging inquiry was made possible by M. D. Anderson’s extensive clinical and genetic data sets, Wu said.

Co-authors with Wu, first author Liang, Ph.D., and Lu are; Jie Lin, Ph.D., Xia Pu, Yuanqing Ye, Ph.D., all in the Department of Epidemiology; and Larissa Meyer, M.D., in the Department of Gynecologic Oncology at M. D. Anderson Cancer Center. Pu is a graduate student at The University of Texas Graduate School of Biomedical Sciences at Houston, which is a joint effort of M. D. Anderson and The University of Texas Health Science Center at Houston.

This research was supported by an award by the Department of Defense Ovarian Cancer Research Program.”

About M. D. Anderson

The University of Texas M. D. Anderson Cancer Center in Houston ranks as one of the world’s most respected centers focused on cancer patient care, research, education and prevention. M. D. Anderson is one of only 40 comprehensive cancer centers designated by the National Cancer Institute. For four of the past six years, including 2008, M. D. Anderson has ranked No. 1 in cancer care in “America’s Best Hospitals,” a survey published annually in U.S. News & World Report.

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