Detection of HPV-DNA,p53alterations, and methylation in penile squamous cell carcinoma in Japanese men

Penile carcinoma is a rare disease, accordingly there are few studies on molecular changes, and these results also vary greatly. A total of 26 penile squamous cell carcinomas in Japanese men were studied with respect to HPV, p53 alterations, and methylation of gene promoter region. HPV-DNA was detected in three of 26 patients (11.5%). Overexpression of p53 was observed in 13 of 26 patients (50%), and p53 gene mutations were detected in four of 26 patients (15.4%). The frequency of methylation was as follows: DAPK, 26.9% (7/26); FHIT, 88.4% (23/26); MGMT, 19.2% (5/26); p14, 3.8% (1/26); p16, 23.1% (6/26); RAR-beta, 23.1% (6/26); RASSF1A, 11.5% (3/26); and RUNX3, 42.3% (11/26). As for correlation between HPV and p53 alterations, and methylation status, mutations of the p53 gene were detected only in HPV-negative patients, and methylation was more frequently found in HPV-negative than in HPV-positive patients. The present results suggest that the majority of penile squamous cell carcinomas in Japanese men are unrelated to HPV, and gene alterations accumulate more frequently in HPV-unrelated penile carcinomas.