Human papillomavirus related anal squamous cell carcinoma survival: a systematic review and meta-analysis

Background: Human papillomavirus (HPV) has been identified to be related to progression of anal squamous cell carcinoma (ASCC). However, the results remain controversial. A meta-analysis of epidemiologic studies was therefore conducted to address this issue. Methods: Data were collected from studies comparing overall survival (OS) and disease-free survival (DFS)/disease-specific survival (DSS)/relapse-free survival (RFS)/progression-free survival (PFS) in patients with HPV infection. The electronic databases of MEDLINE and EMBASE were searched from their inception till 30 Apr 2017. Study-specific risk estimates were pooled using a fixed-effects model for OS and DFS/DSS/RFS/PFS. Results: Seven studies involving a total of 488 ASCC cases were included in this meta-analysis. The pooled results showed that HPV infection was significantly associated with improved OS (HR =0.36; 95% CI, 0.22–0.58) and DFS/DSS/RFS/PFS (HR =0.29; 95% CI, 0.18–0.47). The findings from most subgroup analyses were consistent with those from the overall analysis. Conclusions: The meta-analysis indicated that HPV infection may be of prognostic or therapeutic utility in the evaluation of factors contributing to ASCC. Testing tumor specimens for HPV might indirectly affect the treatment decisions.