Risk Markers Discovered For Erectile Dysfunction

The markers are an important step towards helping clinicians determine the best course of treatment for prostate cancer patients and may lead to the development of therapies that alleviate side effects.

In a landmark Genome-Wide Association Study at Mount Sinai School of Medicine (New York, NY, USA) and the Albert Einstein College of Medicine of Yeshiva University (New York, NY, USA) scientists conducted a two-part study, first, to discover the candidate genetic markers of side effect risk, and second, to confirm which of those markers are replicated in a second group of patients. In the first group of prostate cancer patients, which included 132 men who developed erectile dysfunction after radiotherapy and 103 men similarly treated who did not develop erectile dysfunction.

The scientists identified single nucleotide polymorphisms (SNPs) associated with susceptibility for the development of erectile dysfunction following radiotherapy for prostate cancer. They found a set of genetic markers associated with erectile dysfunction. In the 128 patients who developed erectile dysfunction after radiotherapy and the 102 who did not, researchers confirmed that 12 SNPs were associated with erectile dysfunction. The discovery cohort was genotyped using genome-wide arrays (Affymetrix Inc.; Santa Clara, CA, USA).

The 12 SNPs identified in this study were located near genes that seem to be related to erectile function rather than related to radiation response. The scientists concluded that these SNPs may affect genes that sensitize a patient to developing erectile dysfunction when exposed to radiation during therapy. The authors indicate that examination of a large, independent cohort of similarly treated patients will be necessary to definitively determine which SNPs to include as part of a clinically useful predictive test to identify which men are at greatest risk for developing erectile dysfunction following prostate cancer radiotherapy. The scientists are also evaluating the impact of radiation treatment on urinary complications and proctitis, the inflammation of the rectum.

Harry Ostrer, MD, a professor of Pathology and Genetics, and coprincipal investigator, said, “This is part of our ongoing effort to identify men at highest risk for disease, identify the aggressive tumors that would be responsive to therapy, and to improve quality of life for men with indolent prostate cancers who might benefit from active surveillance, rather than therapy.” The study was published on September 28, 2012, in the International Journal of Radiation Oncology.

Related Links:
Mount Sinai School of Medicine
Albert Einstein College of Medicine
Affymetrix Inc.