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The Cancer Biomarker Conundrum: Too Many False Discoveries

Posted by Paul Cacciatore on August 12, 2010

The boom in cancer [including ovarian] biomarker investments over the past 25 years has not translated into major clinical success. The reasons for biomarker failures include problems with study design and interpretation, as well as statistical deficiencies, according to an article published online August 12 in The Journal of the National Cancer Institute.

The boom in cancer [including ovarian] biomarker investments over the past 25 years has not translated into major clinical success. The reasons for biomarker failures include problems with study design and interpretation, as well as statistical deficiencies, according to an article published online August 12 in The Journal of the National Cancer Institute.

The National Institutes of Health defines a biomarker as “a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention.” In the past decade, there have been numerous biomarker discoveries, but most initially promising biomarkers have not been validated for clinical use.

Eleftherios P. Diamandis, M.D., Ph.D., Head, Section of Clinical Biochemistry, Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada

To understand why so-called biomarker “breakthroughs” have not made it to the clinic, Eleftherios P. Diamandis, M.D., Ph.D., professor of pathology and laboratory medicine at Mount Sinai Hospital in Toronto and associate scientist at the Samuel Lunenfeld Research Institute of Mount Sinai Hospital, reviewed some biomarkers initially hailed as breakthroughs and their subsequent failings.

Diamandis first describes the requirements for biomarkers to be approved for clinical use: A biomarker must be released into circulation in easily detectable amounts by a small asymptomatic tumor or its micro-environment; and it should preferably be specific for the tissue of origin. Also, if the biomarker is affected by a non-cancer disease, its utility for cancer detection may be compromised. For example, the prostate-specific antigen (PSA) biomarker, which is used to detect prostate cancer, is also elevated in benign prostatic hyperplasia.

Diamandis looks at seven biomarkers that have emerged in the past 25 years, all of which were considered promising when they were first described. These include nuclear magnetic resonance of serum for cancer diagnosis; lysophosphatidic acid for ovarian cancer; four- and six-parameter diagnostic panels for ovarian cancer; osteopontin for ovarian cancer; early prostate cancer antigen-2 (EPCA-2) for prostate cancer detection; proteomic profiling of serum by mass spectrometry for ovarian cancer diagnosis; and peptidomic patterns for cancer diagnosis. Problems ranged from inappropriate statistical analysis to biases in case patient and control subject selection. For example, the problems with EPCA-2 included reporting values that were beyond the detection limit of the assay and using inappropriate reagents to test EPCA-2, such as solid surfaces coated with undiluted serum.

Diamandis concludes that “problems with pre-analytical, analytical, and post-analytical study design could lead to the generation of data that could be highly misleading.”

Sources:

The Cancer Biomarker Conundrum: Too Many False Discoveries, Journal of the National Cancer Institute Advance Access,  published on August 12, 2010, DOI 10.1093/jnci/djq335.

Eleftherios P. Diamandis. Cancer Biomarkers: Can We Turn Recent Failures into Success? Commentary, Journal of the National Cancer Institute Advance Access published on August 12, 2010, DOI 10.1093/jnci/djq306.

Posted in Biomarker, Early Detection, Proteomics | Tagged: , , , , , , , , , , , , , , , | Leave a Comment »

President of M.D. Anderson Outlines 10 Steps To Achieve Progress Against Cancer.

Posted by Paul Cacciatore on March 31, 2009

“The Houston Chronicle recently published a commentary by John Mendelsohn, M.D., president of M. D. Anderson, outlining actions the nation should take to achieve great progress against cancer. … Here are 10 steps we can take to ensure that deaths decrease more rapidly, the ranks of survivors swell, and an even greater number of cancers are prevented in the first place. …”

“Ten Pieces Help Solve Cancer Puzzle

John Mendelsohn, M.D., President, The University of Texas M.D. Anderson Cancer Center

John Mendelsohn, M.D., President, The University of Texas M.D. Anderson Cancer Center

The Houston Chronicle recently published a commentary by John Mendelsohn, M.D., president of M. D. Anderson, outlining actions the nation should take to achieve great progress against cancer.

An American diagnosed with cancer today is very likely to join the growing ranks of survivors, who are estimated to total 12 million and will reach 18 million by 2020. The five-year survival rate for all forms of cancer combined has risen to 66%, more than double what it was 50 years ago.

Along with the improving five-year survival rates, the cancer death rate has been falling by 1% to 2% annually since 1990.

According to the World Health Organization, cancer will be the leading worldwide cause of death in 2010. Over 40% of Americans will develop cancer during their lifetime.

While survival rates improve and death rates fall, cancer still accounts for one in every five deaths in the U.S., and cost this nation $89.0 billion in direct medical costs and another $18.2 billion in lost productivity during the illness in 2007, according to the National Institutes of Health.

Here are 10 steps we can take to ensure that deaths decrease more rapidly, the ranks of survivors swell, and an even greater number of cancers are prevented in the first place.

#1.  Therapeutic cancer research should focus on human genetics and the regulation of gene expression.

Cancer is a disease of cells that have either inherited or acquired abnormalities in the activities of critical genes and the proteins for which they code. Most cancers involve several abnormally functioning genes – not just one – which makes understanding and treating cancer terribly complex. The good news is that screening for genes and their products can be done with new techniques that accomplish in days what once took years.

Knowledge of the human genome and mechanisms regulating gene expression, advances in technology, experience from clinical trials, and a greater understanding of the impact of environmental factors have led to exciting new research approaches to cancer treatment, all of which are being pursued at M. D. Anderson:

  • Targeted therapies.  These therapies are designed to counteract the growth and survival of cancer cells by modifying, replacing or correcting abnormally functioning genes or their RNA and protein products, and by attacking abnormal biochemical pathways within these cells.
  • Molecular markers.  Identifying the presence of particular abnormal genes and proteins in a patient’s cancer cells, or in the blood, will enable physicians to select the treatments most likely to be effective for that individual patient.
  • Molecular imaging.  New diagnostic imaging technologies that detect genetic and molecular abnormalities in cancers in individual patients can help select optimal therapy and determine the effectiveness of treatment within hours.
  • Angiogenesis.  Anti-angiogenesis agents and inhibitors of other normal tissues that surround cancers can starve the cancer cells of their blood supply and deprive them of essential growth-promoting factors which must come from the tumor’s environment.
  • Immunotherapy. Discovering ways to elicit or boost immune responses in cancer patients may target destruction of cancer cells and lead to the development of cancer vaccines.

#2.  Better tests to predict cancer risk and enable earlier detection must be developed.

New predictive tests, based on abnormalities in blood, other body fluids or tissue samples, will be able to detect abnormalities in the structure or expression of cancer-related genes and proteins. Such tests may predict the risk of cancer in individuals and could detect early cancer years before any symptoms are present.

The prostate-specific antigen test for prostate cancer currently is the best known marker test to detect the possible presence of early cancer before it has spread. Abnormalities in the BRCA 1 and BRCA 2 genes predict a high risk for breast cancer, which can guide the decisions of physicians and patients on preventive measures. Many more gene-based predictors are needed to further our progress in risk assessment and early detection.

#3.  More cancers can and must be prevented.

In an ideal world, cancer “care” would begin with risk assessment and counseling of a person when no malignant disease is present. Risk factors include both inherited or acquired genetic abnormalities and those related to lifestyle and the environment.

The largest risk factor for cancer is tobacco smoking, which accounts for nearly one-third of all cancer deaths. Tobacco use should be discouraged with cost disincentives, and medical management of discontinuing tobacco use must be reimbursed by government and private sector payors.

Cancer risk assessment should be followed by appropriate interventions (either behavioral or medical) at a pre-malignant stage, before a cancer develops. Diagnosis and treatment of a confirmed cancer would occur only when these preventive measures fail.

A full understanding of cancer requires research to identify more completely the genetic, environmental, lifestyle and social factors that contribute to the varying types and rates of cancer in different groups in this country and around the world. A common cancer in Japan or India, for example, often is not a common cancer in the U.S. When prostate cancer occurs in African-Americans it is more severe than in Caucasians. A better understanding of the factors that influence differences in cancer incidence and deaths will provide important clues to preventing cancer in diverse populations worldwide.

#4.  The needs of cancer survivors must become a priority.

Surviving cancer means many things: reducing pain, disability and stress related to the cancer or the side effects of therapy; helping patients and their loved ones lead a full life from diagnosis forward; preventing a second primary cancer or recurrence of the original cancer; treating a difficult cancer optimally to ensure achieving the most healthy years possible, and more.  Since many more patients are surviving their cancers – or living much longer with cancer – helping them manage all the consequences of their disease and its treatment is critically important.  It is an area ripe for innovative research and for improvement in delivery of care.

#5.  We must train future researchers and providers of cancer care.

Shortages are predicted in the supply of physicians, nurses and technically trained support staff needed to provide expert care for patients with cancer.  On top of this, patient numbers are projected to increase.  We are heading toward a “perfect storm” unless we ramp up our training programs for cancer professionals at all levels.   The pipeline for academic researchers in cancer also is threatened due to the increasing difficulty in obtaining peer-reviewed research funding. We must designate more funding from the NIH and other sources specifically for promising young investigators, to enable them to initiate their careers.

#6.  Federal funding for research should be increased.

After growing by nearly 100% from 1998-2002, the National Cancer Institute budget has been in decline for the past four years. Through budget cuts and the effects of inflation, the NCI budget has lost approximately 12% of its purchasing power.  Important programs in tobacco control, cancer survivorship and support for interdisciplinary research have had significant cuts.  The average age at which a biomedical researcher receives his or her first R01 grant (the gold standard) now stands at 42, hardly an inducement to pursue this field. This shrinks the pipeline of talented young Americans who are interested in careers in science, but can find easier paths to more promising careers elsewhere.  Lack of adequate funding also discourages seasoned scientists with outstanding track records of contributions from undertaking innovative, but risky research projects.  The U.S. leadership in biomedical research could be lost.

Biomedical research in academic institutions needs steady funding that at least keeps up with inflation and enables continued growth.

#7.  The pace of clinical research must accelerate.

As research ideas move from the laboratory to patients, they must be assessed in clinical trials to test their safety and efficacy. Clinical trials are complicated, lengthy and expensive, and they often require large numbers of patients.  Further steps must be taken to ensure that efficient and cost-effective clinical trials are designed to measure, in addition to outcomes, the effects of new agents on the intended molecular targets. Innovative therapies should move forward more rapidly from the laboratory into clinical trials.

The public needs to be better educated about clinical trials, which in many cases may provide them with access to the best care available.  Greater participation in trials will speed up drug development, in addition to providing patients with the best options if standard treatments fail.  The potential risks and benefits of clinical trials must continue to be fully disclosed to the patients involved, and the trials must continue to be carefully monitored.

The issue of how to pay for clinical trials must be addressed. The non-experimental portion of the costs of care in clinical trials currently are borne in part by Medicare, and should be covered fully by all payors. The experimental portion of costs of care should be covered by the owner of the new drug, who stands to benefit from a new indication for therapeutic use.

#8.  New partnerships will encourage drug and device development.

One way to shorten the time for drug and device development is to encourage and reward collaboration among research institutions, and collaboration between academia and industry.  Increasingly, partnerships are required to bring together sufficient expertise and resources needed to confront the complex challenges of treating cancer. There is enormous opportunity here, but many challenges, as well.

Academic institutions already do collaborate, but we need new ways to stimulate increased participation in cooperative enterprises.

Traditionally, academic institutions have worked with biotech and pharmaceutical companies by conducting sponsored research and participating in clinical trials.  By forming more collaborative alliances during the preclinical and translational phases prior to entering the clinic, industry and academia can build on each other’s strengths to safely speed drug development to the bedside. The challenge is that this must be done with agreements that involve sharing, but also protect the property rights and independence of both parties.

The results of all clinical trials must be reported completely and accurately, without any influence from conflicts of interest and with full disclosure of potential conflicts of interest.

#9. We must provide access to cancer care for everyone who lives in the U.S.

More than 47 million Americans are uninsured, and many others are underinsured for major illnesses like cancer. Others are uninsurable because of a prior illness such as cancer.  And many are indigent, so that payment for care is totally impossible.

Depending on where they live and what they can afford, Americans have unequal access to quality cancer care. Treatment options vary significantly nationwide. We must find better ways to disseminate the best standards of high-quality care from leading medical centers to widespread community practice throughout the country.

Cancer incidence and deaths vary tremendously among ethnic and economic groups in this country. We need to address the causes of disparities in health outcomes and move to eliminate them.

We are unique among Western countries in not providing direct access to medical care for all who live here. There is consensus today among most Americans and both political parties that this is unacceptable.  Especially for catastrophic illnesses like cancer, we must create an insurance system that guarantees access to care.

A number of proposals involving income tax rebates, vouchers, insurance mandates and expanded government insurance programs address this issue. Whatever system is selected should ensure access and include mechanisms for caring for underserved Americans.  The solution will require give-and-take among major stakeholders, many of which benefit from the status quo.  However, the social and economic costs have risen to the point that we have no choice.

#10.  Greater attention must be paid to enhancing the quality of cancer care and reducing costs.

New therapies and medical instruments are expensive to develop and are a major contributor to the rising cost of medical care in the U.S.  The current payment system rewards procedures, tests and treatments rather than outcomes.  At the same time, cancer prevention measures and services are not widely covered.  A new system of payment must be designed to reward outcomes, as well as the use of prevention services.

Quality of care can be improved and costs can be reduced by increasing our efforts to reduce medical errors and to prescribe diagnostic tests and treatments only on the basis of objective evidence of efficacy.

A standardized electronic medical record, accessible nationwide, is essential to ensuring quality care for patients who see multiple providers at multiple sites, and we are far behind many other nations.  Beyond that, a national electronic medical record could provide enormous opportunities for reducing overhead costs, identifying factors contributing to many illnesses (including cancer), determining optimal treatment and detecting uncommon side effects of treatment.

What the future holds in store.

I am optimistic. I see a future in which more cancers are prevented, more are cured and, when not curable, more are managed as effectively as other chronic, life-long diseases. I see a future in which deaths due to cancer continue to decrease.

Achieving that vision will require greater collaboration among academic institutions, government, industry and the public.  Barriers to quality care must be removed.  Tobacco use must be eradicated.  Research must have increased funding.  Mindful that our priority focus is on the patient, we must continue to speed the pace of bringing scientific breakthroughs from the laboratory to the bedside.

M. D. Anderson resources:

John Mendelsohn, M.D.”

Primary SourceTen Pieces Help Solve Cancer Puzzle, by John Mendelsohn, M.D., Feature Article, The University of Texas M.D. Anderson Cancer Center Cancer News, Mar. 2009.

Posted in Advocacy, Biological Therapies, Clinical Trials, Diagnosis & Treatment, Early Detection, Inspirational, Molecular Diagnostics, Novel Therapies, Prevention, Survivorship | Tagged: , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a Comment »

 
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