Genetic alterations at 13q14 may correlate with differences in the biological behavior of prostate cancer between Japanese and Caucasian men.

The incidence of prostate cancer and the resultant mortality rates in Japanese men are lower compared with the rates for Caucasians; however, the Gleason score at diagnosis is higher in Japanese men compared with Caucasians. Loss of 13q is one of the most common chromosomal alterations in prostate cancer. To elucidate the difference in the rate of loss of 13q between Japanese and Caucasian men, we examined the allelic imbalance (AI) on chromosome 13q in 32 Japanese and 39 German prostate cancer patients with a fluorescent polymerase chain reaction technique using 12 microsatellite markers. Benign and malignant histology was identified by a single pathologist and laser capture microdissection was used to gather cancer cells. Although there were no statistical differences in patient background characteristics, the frequency of AI at 13q14 (D13S1253) and at 13q21 (D13S166) was significantly higher in Japanese patients compared with German patients (p = 0.0128 and p = 0.0078, respectively). The frequency of AI at 13q14 was significantly higher in tumors with high Gleason scores (GS) compared with tumors with low GS (p = 0.0478). The present observations suggest that the frequency of genetic alterations at 13q14 may underlie differences in the biological behavior of prostate cancer between Japanese and Caucasian populations.