Association of HER-2 polymorphism with Japanese sporadic prostate cancer susceptibility

Genetic polymorphisms may affect the development of prostate cancer (Pca). HER-2 is a proto-oncogene that has an important role in many human cancers, including Pca. To determine the association of the HER-2 gene with Japanese sporadic Pca, we analyzed the frequency of codon 655 (A/G, isoleucine, or valine) in case and control group.

We genotyped Ile 655 Val in Pca patients (n = 285) and in matched controls (n = 233). Statistical analyses were performed by Fisher's exact test and logistic regression analysis.

We observed a significantly lower frequency of the Val655 allele in the Pca patients (14.7%) compared to the control group (26.2%) (P = 0.0025, odds ratio (OR) = 0.476, 95% CI = 0.306-0.740). This SNP was not found to be correlated with clinical stage, PSA level, Gleason score of biopsies or age at diagnosis.

Our results indicate that the frequency of Val655 in HER-2 was significantly lower in Japanese Pca patients, however, it was recently reported that Val655 was significant higher in breast cancer patients. This contradictory observation in prostate and breast cancer patients is interesting considering the opposite hormonal sensitivity of these two cancers.