Human papillomavirus as a favorable prognostic biomarker in squamous cell carcinomas of the vagina.

Objective: Recent evidence has confirmed two independent pathways in the development of vaginal squamous cell carcinoma (VaSCC): one related to and the other independent of human papillomavirus (HPV). The aim of our study was to evaluate whether HPV status has prognostic significance in this neoplasm.
Methods: All confirmed primary VaSCCs diagnosed and treated from 1995 to 2009 in two institutions were retrospectively evaluated (n=57). HPV infection was detected by PCR using SPF-10 primers and typed with the INNO-LIPA HPV assay and p16(INK4a) expression by immunohistochemistry. Disease-free and overall survival (DFS and OS) were analyzed by Kaplan-Meier analysis with the log-rank test and a multivariate Cox proportional hazard's model.
Results: HR-HPV DNA was detected in 70.2% patients. HPV16 was the most prevalent genotype (67.5% of cases). p16(INK4a) was positive in 97.5% HPV-positive and 17.6% HPV-negative tumors (p<.001). FIGO stage was associated with DFS (p=.042) and OS (p=.008). HPV-positive tumors showed better DFS (p=.042) and OS (p=.035) than HPV-negative tumors. Multivariate analysis confirmed better DFS and OS of HPV-positive patients independent of age and stage. This reduced risk of progression and mortality in HPV-positive patients was limited to women with FIGO stages I and II tumors (HR=0.26; 95% CI 0.10-0.69; p=0.006).
Conclusions: HPV-positive early stage (FIGO I and II) VaSCCs have a better prognosis than early HPV-negative tumors. HPV detection and/or p16(INK4a) immunostaining can be easily implemented in routine pathology and should be considered as valuable prognostic biomarkers in the study of patients with VaSCC.
(Copyright © 2012 Elsevier Inc. All rights reserved.)