Cancer of the anus (anal canal) is a less frequent malignant disease of gastrointestinal tract, specified by micromorphology, squamous cell carcinoma. In about 90 % HPV-16 infection and immunosuppression are involved in cancerogenesis.
Therefore the incidence is higher in HIV positive population. The relationship to HPV allows primary prevention through vaccination as well as targeted biologic therapy (e.g. nivolumab).
Current treatment options consist predominantly in chemoradiotherapy. Standard treatment is based on several fundamental studies conducted after 1980.
It consists in frontline chemoradiotherapy of primary tumor and regional lymph nodes up to a dose 54-60 Gy eq, concomitant chemoradiotherapy mitomycin + 5-fluorouracil or cisplatinum + 5-fluorouracil. Complete regression is achieved in 90%, 5 year survival up to 70 % and 5 year relapse free survival up to 70%.
There is no benefit of either induction chemotherapy or chemotherapy after radiotherapy. Surgery is indicated as a salvage therapy for local relapse or if a complete regression is not achieved.
Acute and chronic toxicity of chemoradiotherapy regimens presents a substantial problem of chemoradiotherapy. It may be partially reduced by more advanced radiotherapy technologies.
Targeted biologic therapy including anticancer vaccines is still a subject of preclinical or early clinical research.