Objectives: Rare HRAS1 variable number tandem repeats (VNTR) have been associated with increased risks for a variety of cancers. We investigated the relationship of this polymorphism with the risk of prostate cancer among 240 cases and 481 control subjects in the Health Professionals Follow-up Study.
Materials and Methods: The HRAS1 VNTR region of leukocyte DNA was polymerase chain reaction amplified, and fragment lengths were determined by automated fluorescence detection and computer analysis. We estimated the odds ratios (OR) of prostate cancer for rare HRAS1 VNTR from logistic regression models. Four common HRAS1 VNTR alleles were identified about which there was a distribution of rare 28-nucleotide repeat units. There was no difference (p = 0.4) in the prevalence of rare alleles between cases (25.8%) and control subjects (23.7%). Compared to common alleles, the OR for prostate cancer was 1.13 (95% confidence interval 0.87–1.45) for rare alleles.
Conclusions: This study suggests that rare HRAS1 VNTRs may not be important in the etiology of prostate cancer.