HPV status in relation to clinicopathologic variables in patients with penile cancer at Los Angeles County-USC Medical Center.

Abstract

329 Background: Penile squamous cell carcinoma (PSCC) is a disfiguring and deadly disease. US cancer registry reports a higher incidence in certain minority communities including those over-represented at LAC-USC. Human papilloma virus (HPV) infection is strongly associated with PSCC. This study examined correlations of HPV presence and subtype with PSCC patient clinicopathological variables. Methods: After IRB approval, a retrospective review of PSCC patients at LAC-USC between 1996-2010 was completed. HPV presence and genotype was detected from primary tumors of 33 patients by DNA amplification followed by reverse line blot hybridization. Associations with patient and tumor characteristics were examined by contingency analyses. Results: 20 (60.6%) patients were HPV+, and 85% of all HPV+ cases harbored at least one high-risk viral strain (80% of all positive cases had HPV 16, 5% HPV 31, 10% HPV 66). 20% of all positive cases harbored low-risk HPV 11; HPV strains 6 or 35 were not detected in any specimen. 3 patients were positive for multiple strains. Overall median age at diagnosis was 53 (range: 24-77) yrs. Median age was 56 yrs and 49 yrs for HPV+ and HPV- patients, respectively. HPV infection showed a trend towards being more prevalent in patients beyond the fifth decade of life, although this did not reach statistical significance (p=0.10). 22 (66.7%) patients were Hispanic; this ethnicity comprised 60% and 77% of HPV+ and HPV- cases, respectively (p=0.31). This cohort included Stage 0 (n= 1, n= 0), Stage 1 (n= 4, n=2), Stage 2 (n= 4, n= 4), Stage 3 (n=5, n= 1), and Stage 4 (n= 4, n= 5) HPV+ and HPV- patients, respectively. Neither HPV status nor presence of nodal metastasis was significantly associated with stage (p=0.50, p=0.52 respectively). Tumor grade was available for 30 (90.9%) cases; while HPV+ cases tended to have higher proportion of moderately-poorly differentiated tumors than HPV- cases (77.8% vs. 58.3%), this was not statistically significant (p=0.32). Conclusions: An overwhelming majority of HPV+ cases harbored at least one high-risk viral strain. Several interesting associations of HPV status with age and grade were noted, although the study was underpowered to show significance.