Human papillomavirus in anal squamous cell carcinoma: an angel rather than a devil?

Anal cancer is a rare disease with an increasing incidence worldwide but, unfortunately, even today the scientific community still has a limited knowledge and limited options of treatment. More than 50% of patients with anal cancer presenting at diagnosis with locoregional disease have good chances of cure with chemoradiotherapy (CT-RT). However, once patients develop metastatic spread, the prognosis is very poor. Human papillomavirus (HPV) is present in more than 80% of anal cancers and while multiple etiologic connections between HPV infection and anal cancer have already been well elucidated, its prognostic and/or predictive role is currently under investigation, especially among immunocompetent patients affected by this disease. In a single-institutional set, we have retrospectively analysed clinical data of 50 consecutive cases homogeneously treated with CT-RT for stage I-III anal squamous cell carcinoma. We found that HPV-positive anal cancers had a statistically significant improved five-year disease-free survival (DFS) compared to HPV-negative group. These findings could be explained by an increased chemo/radiosensitivity of HPV-positive tumours. Further efforts should be directed towards a better understanding of HPV-related oncogenesis and towards designing novel tailored strategies for the management of this disease both in terms of prevention and treatment.