Genetic markers associated with earlier PCa diagnosis

Two novel genetic markers appear to be associated with earlier time to prostate cancer diagnosis among African-American men, according to research presented at the American Association for Cancer Research annual meeting in Orlando, FL.

Co-author Veda Giri, MD, of Fox Chase Cancer Center, Philadelphia and colleagues have been researching genetic variations in microRNA (miRNA) binding sites and found that two genes, IL-16 and IL-18, show variations associated with a two-fold or greater increased risk of early prostate cancer diagnosis in African-American men who are undergoing screening.

"We have found some preliminary data supporting the idea that genetic variation in miRNA target sites can influence prostate cancer risk," Dr. Giri said. "If we confirm these data, then we might be able to use these sites, along with other known genetic variants, to help individualize prostate screening in the future."

Dr. Giri noted that although miRNAs were only discovered recently, their role in cancer susceptibility is being rapidly uncovered, probably because they control expression of genes involved in tumor formation, progression, and metastasis.

Dr. Giri’s team analyzed single nucleotide polymorphisms (SNPs) in miRNA binding sites in four genes in approximately 750 men enrolled in the Prostate Cancer Risk Assessment Program at Fox Chase. None of the SNPs were associated with prostate cancer risk in Caucasian men.

However, African-American men who carried a genetic variant in the miRNA binding site in the IL-16 gene had a 2.27-fold increased risk of early diagnosis, compared with African-American men who did not carry the variant, a statistically significant association (p=.013).

"Our goal is to develop individualized prostate cancer screening approaches, particularly for high-risk men," Dr. Giri said. "Therefore, our research is focused on identifying which men may develop lethal or clinically meaningful prostate cancer in order to screen these men for benefit, while sparing other men unnecessary tests and procedures. Down the road, these new markers may help us do that."

Look for more news from the American Association for Cancer Research annual meeting in an upcoming issue of Urology Times.