Researchers have identified a new genetic marker that may be associated with earlier time to diagnosis of prostate cancer in Caucasian men who have a family history of the disease.
If the data are confirmed, the marker could help clinicians personalize prostate cancer screening.
“Genetic testing for prostate cancer is not clinically well characterized yet as it is for breast, ovarian cancer, and colon cancer,” said lead investigator Veda N. Giri, MD, a medical oncologist and Director of the Prostate Cancer Risk Assessment Program at Fox Chase Cancer Center in Philadelphia.
“Markers such as this one are useful because they may help clinicians distinguish between men who are at risk for being diagnosed with prostate cancer earlier, when intensive screening approaches can be discussed. Men who do not carry genetic markers of risk may not need such screening measures.”
More than half of all prostate tumors carry a fusion gene called TMPRSS2-ERG, which may have a role in prostate cancer formation. Recently, researchers reported that a single nucleotide polymorphism (SNP), called Met160Val, is associated with the gene fusion. Specifically, prostate cancer patients who carry the T allele of Met160Val SNP are more likely to have a prostate tumor with the gene fusion than patients who have the C allele.
To find out if the T allele is clinically relevant in men at high risk of developing prostate cancer, Dr. Giri and her colleagues genotyped 631 men high-risk men and evaluated this marker in men undergoing follow-up screening.
While no association to time to diagnosis for prostate cancer was seen in African American men, there was a significantly earlier time to prostate cancer diagnosis for Caucasian men with a family history of prostate cancer in men with the CT or TT genotype than in men with the CC genotype.
“This was a pilot study,” Dr. Giri said. “We are expanding the study to see if the association holds up in a larger Caucasian patient population. We are also planning collaborations with investigators at other institutions to test if this marker would be informative in African-American men with a family history.”
She said her study did not have enough African-American men with a family history of prostate cancer to test that possibility.