A Personalized Approach: The Role of Commercially Available Genetic Tests
Prostate Cancer is the most commonly diagnosed malignancy in American men. Patients and their doctors face many challenges when it comes to prostate cancer, particularly the broad spectrum of how it behaves (slow growing versus aggressive) and the multitude of treatment options available for localized and metastatic disease (when cancer has spread beyond the prostate).
What has been missing is a more personalized approach to each patient with newly diagnosed prostate cancer. Patients want to know about their own prostate cancer. How aggressive is my prostate cancer? What are the chances it will come back after initial treatment? Would it be safe to start with active surveillance?
Genetic testing for newly diagnosed prostate cancer has become increasingly popular in the last three years. Commercially available genetic tests, covered by some insurance plans, allow prostate cancer patients to get a glimpse into their own DNA – a true look into the biology of their cancer.
With commercially available genetic testing, we have a new tool in our toolbox to add to the standard testing to help make informed decisions about treatment.
How the tests work
Most of the commercially available genetic tests use a small piece of the prostate biopsy tissue previously analyzed by the pathologist (the doctor who makes the diagnosis by looking under the microscope). In addition, a small piece of the surgically removed prostate can be used to run the genetic tests. A panel of genes is examined.
Commonly available tests that use prostate cancer tissue include Onctotype Dx®, Prolaris ® and Decipher®. Another test called Confirm MDX® looks at the tissues of prostate biopsies that showed no cancer and helps decide if another biopsy might be positive for cancer. Finally, Select MDX™ utilizes a urine test to predict the likelihood of having prostate cancer on subsequent biopsy.
All of these genetic tests have been validated and shown to provide valuable prognostic information. The results of the tests are user friendly and easily interpreted by patients and clinicians. Some tests offer a prediction of disease aggression and likelihood of the cancer progressing. As more of these tests are being used and studied, we are learning that they can impact treatment decisions in a positive manner. For example, patients who are on the fence about doing active surveillance versus treatment (e.g., surgery or radiation) can use the results of the genetic tests, along with other information about the cancer, to help make a decision.
The diversity in how prostate cancer behaves has been one of the biggest challenges facing patients and clinicians. To screen or not to screen? To treat or not to treat? These controversies will likely continue in the near future, but the myriad of genetic tests available today is a major step forward in our fight against this disease.
References:
Genomic Predictors of Outcome in Prostate Cancer. European Urology: 68 (2015); 1033-1044.