Recent data point to certain genetic biomarkers that may identify which patients have fast-growing malignancies and should be treated aggressively versus those who can be directed to “active surveillance” or close monitoring. The National Comprehensive Cancer Network prostate cancer treatment guidelines were also recently updated to include recommendations for patients who fall into these categories.
"Developing a clinically validated prostate cancer prognostic assay with actionable data represents the 'holy grail' in improving disease management," said James Brooks, M.D., associate professor and acting chair, Department of Urology, Stanford University Medical Center. "It clearly would fulfill an unmet medical need to help men with prostate cancer know which treatment options will yield the best outcomes for their long-term survival and best quality of life. Certain men found to have slow-growing cancers could safely opt for no treatment and avoid life-altering side effects."
Prostate cancer, the second most common cancer in men, with an estimated U.S prevalence of 2.3 million, is usually diagnosed with a biopsy of prostate tissue. If cancer is found, the patient and physician must decide on treatment options, ranging from no treatment to aggressive management with radiation and chemotherapy or surgical removal of the prostate. Because prostate cancer treatments may have side effects like erectile dysfunction and urinary incontinence, treatment decisions may focus on balancing therapeutic goals with a patient’s age and other factors such as diet, exercise and lifestyle. In most cases, decisions rest on health-adjusted life expectancies.
In certain men, prostate tumors may grow so slowly that no treatment is required. However, there is no test or procedure available at this time that can optimally discriminate benign from aggressive disease. Fearing the worst outcomes, many men opt for aggressive treatment even though it might not be needed.
Abbott will develop a molecular assay based on its proprietary FISH (fluorescence in situ hybridization) technology to detect rearrangements of the ERG and ETV1 genes and measure loss of the PTEN gene. A study published in the British Journal of Cancer evaluated 308 men diagnosed with prostate cancer who were treated conservatively. Those who did not show ERG/ETV1 genetic aberrations with no PTEN gene loss had excellent prognosis, evidenced by an 85 percent survival rate after 11 years. Men who showed PTEN gene loss in the absence of the gene rearrangements had a poor survival rate of 13.7 percent. The study showed the promise of the new biomarkers to identify patients who would benefit most from intensive therapies.
Abbott’s FISH probes to detect the ERG/ETV1 gene and measure PTEN gene loss will be evaluated as part of scientific research starting some time later this year.
"This is a meaningful breakthrough for men who have to make the agonizing decision regarding treatments for prostate cancer," said Stafford O’Kelly, head of Abbott’s molecular diagnostics business. "Without knowing if the cancer is life threatening, men have no way to know if prostate surgery or chemotherapy is the right option. This newest advance in personalized medicine will provide individualized genetic evidence for informed clinical decision making in choosing the right approach to prostate cancer treatment."