P16 (CDKN2 MTS1) GENE DELETIONS ARE RARE IN PROSTATIC CARCINOMAS IN THE UNITED-STATES AND JAPAN/

Purpose: The incidence of clinically apparent prostatic carcinoma is m uch higher in the United States than in Japan. Alterations in the p16 tumor suppressor gene have been identified in various tumor types, inc luding cultured prostatic carcinoma cell lines. We studied the possibl e deletions of either exon 2 or 3 of this gene in primary clinical pro static carcinomas from Japan and the United States. Materials and Meth ods: Genomic DNA was extracted from 36 formalin-fixed, paraffin-embedd ed clinical prostatic carcinomas from Japan and 27 carcinomas from the United States. Exons 2 and 3 of the p16 gene were amplified using com parative multiplex polymerase chain reactions (PCR) and then analyzed for possible deletions of either exon. Results: Two out of 36 (5.6%) c arcinomas from Japan clearly demonstrated deletion of p16 exon 2, but this deletion was not detected in any of the 27 carcinomas from the Un ited States. Conclusions: Although slightly higher in Japan than in th e United States, the frequency of p16 exon deletions in clinical prost atic carcinomas is very low, and probably is not important in the deve lopment of this neoplasm.