Advances in Biomarkers Promise to Drive Patient Clarity
With progress in new biomarkers, we will see more clarity–for patients and physicians alike–in making better informed decisions.
The more we understand about a patient’s specific variety of prostate cancer and its propensity to be aggressive or not, the better his treatment will be. It’s the promise of precision medicine. It’s the key to eliminating the pitfalls of both over-treating and under-treating. Identifying key signatures–specifically genetic characteristics–of various types of prostate cancer and moving them into clinical practice is making important progress.
I’ve already referenced a novel urine test that is being forwarded by the University of Michigan. It identifies levels of TMPRSS2:ERG and PC3A biomarkers and can better inform which patients with rising PSA need to have a biopsy performed and which can wait for subsequent PSA data before making a decision. It can also stratify those that do not need a biopsy.
Now, Genomic Health, Inc., a cancer diagnostics company based in California that specializes in developing genomic biomarkers used to personalize treatment for cancer patients, released top-line results from a study conducted with UCSF that demonstrates that a multi-gene signature can be used at the time of initial biopsy of the prostate to predict the probability for high-risk cancers—even when initial biopsy shows low risk cancer. (A needle biopsy–even when taking up to 12 different tissue samples from various areas of the prostate–only measures less than 1 percent of the entire gland, increasing the potential to miss areas of high risk tumor.)
Finding this predictive “signature” began with studies done at the Cleveland Clinic that looked at cancerous tissue taken from some 700 men whose prostates had been surgically removed. In men who went on to develop metastatic prostate disease, a pattern of gene signature expression became apparent where certain genes were either predictably up-regulated, making excess RNA, or down-regulated, making too little RNA. The work was presented at the 2012 ASCO meeting with Dr. Eric Klein of the Cleveland Clinic as the lead author.
These findings have broad and promising applications, not only for men who are to test “positive” for the high-risk multi-gene signature, and for whom aggressive treatment may be the best option; but also, this may allow men who test “negative” for the high-risk multi-gene signature to more confidently opt for a program of active surveillance of their disease, deferring surgery and radiation and avoid side effects that can be attributable to those treatments, such a incontinence or erectile dysfunction.
Advances in biomarkers to assess the potential aggressiveness of a patient’s cancer will someday soon address a critical treatment decision faced by hundreds of thousands of men each year around the world—whether to opt for active surveillance when low grade cancer is found at initial biopsy or to decide on a more aggressive treatment plan.
New tests such as these will not only provide much needed clarity for patients, it will also take the heat off of the often misunderstood and maligned PSA test.