Are you really a candidate for genetic testing for cancer susceptibility?

November 9, 7:26 AMMiami Women's Health ExaminerBeth Gilbert

Previous

Comment Print Email RSS Subscribe

Subscribe

Get alerts when there is a new article from the Miami Women's Health Examiner. Read Examiner.com's terms of use.

Email Address   Include other special offers from Examiner.com Terms of Use

Questions Surrounding Genetic Testing
http://www.concurringopinions.com/archives/2005/10/genetic_testing.html

With advances in genetic sequencing and expression analysis, genetic tests for various biomarkers have become more prevalent. However, the question arises whether you are a candidate for genetic testing for diagnosis, prevention, management or treatment of various diseases.

The greatest advances in biomarker identification have been in cancer, including tests that predict your risk of getting cancer, determining treatment and guiding management. Many of the genetic testing companies would like to get you into your specialist’s and primary care physician’s office asking for genetic testing but what will the results tell you, will they guide management or change your daily activities? The answer to these questions remains unknown. However, early advances have shown the drive toward personalized medicine and the role genetics will play in the diagnosis and treatment of various disease states.

Several companies have pipelines of various genetic tests for breast cancer, colon cancer, melanoma and others to guide cancer therapy. Others also has tests that guide chemotherapy use. In addition, laboratoties have panels of biomarkers that can be used to diagnose and guide cancer treatment but the efficacy of some of these panels remains unproven. The biggest advance in predictive tests is testing for breast and ovarian cancer. However, the implications of this testing to date remains incomplete, as the test only predicts risk of cancer, with no preventative treatment options aside from mastectomy and ovariectomy as options in high risk individuals. Yet, the advent of target therapies that may address these mutations may provide options for this at risk patient population.

So, while these tests are becoming more readily available, they are not screening tools rather diagnostic tools and come at a high price tag. Yet, the implications on the patient’s course of action remains limited to date. I do not think that many individuals are aware that only approximately 10% of patients with breast and ovarian cancer carry the risk of these mutations. However, the risk of developing breast and ovarian cancer if you have these mutations ranges from 75% to 85% over the course of a lifetime, which is the reason for strong focus in appropriate patients.

The key word is "appropriate patients", with any of these tests and if you question your primary care physician or specialist regarding these tests be prepared for a genetic susceptibility assessment or potential referral to a genetic counselor, cause while your mom may have developed cancer at 85 that doesn’t mean you are a candidate for any of these genetic tests. In addition, if you have cancer and are being assessed for treatment strategy, please note that your practicing clinician will work with you on the best course of action despite your results.

So the question still remains, am I candidate for genetic testing and what will testing tell me that I don’t already know? At this point in time, the question still remains unclear but as genetic sequencing and expression analysis continue to ramp, the move toward targeted approaches and personalized medicine may provide the answers to the question of disease susceptibility and provide solid reasons for testing.