Anal canal cancer diagnosis and treatment aspects

Anal cancer represents a rare neoplasia, accounting for approximately 1.5% of all digestive cancers, but remains an important concern due to its association to sexually-transmitted infections and still dismal prognosis. This review focuses on the main diagnostic and treatment aspects concerning anal canal cancer. Anal cancer incidence has been increasing in the last years, probably due to the rise in the spread of sexually transmitted diseases, such as HPV and HIV infections. Although many risk factors have been associated to anal cancer (HPV, HIV infection, immunocompromised status, tobacco smoking), anal cancer biology is only partly understood. The most frequent histopathologic type of anal canal cancer is represented by squamous-cell carcinoma (80% of all anal canal cancers). Anal canal cancer should be distinguished from anal margin cancer, which is of better prognosis. Anal cancer diagnosis is usually delayed, due to its resemblance to benign perianal pathology that justifies the need for a better screening. Anal canal carcinoma therapeutic management has witnessed a major shift in time from a radical surgical (abdominoperineal resection) to multimodal approach. Nowadays, the standard treatment of anal carcinoma is represented by radiochemotherapy that is an effective therapy although can associate an important toxicity. Surgical treatment is reserved only to very small anal lesions and especially to residual disease or tumor recurrences after primary therapy, representing a salvage therapy (abdominoperineal rectal amputation) for these cases.  Although approximately 10-30% of the patients present with inguinal lymph node metastases at initial diagnosis, prophylactic inguinal lymphadenopathy is not recommended, due to its associated complications and better response to radiotherapy. Inguinal lymphadenectomy is only indicated for voluminous lymphadenopathy blocks and inguinal lymph node metastases appeared after radiochemotherapy.