Squamous cell anal cancer: Management and therapeutic options

The incidence of anal cancer has increased during the second half of the 20th century, with an incidence rate over 2.9% greater than in the decade of 1992–2001. Yet, it still constitutes a small percentage, about 4%, of all anorectal tumours. Its risk factors are human papillomavirus infection, a history of sexually transmitted diseases, a history of vulvar or cervical carcinoma, immunosuppression related to human immunodeficiency virus infection or after organ transplantation, haematological or immunological disorders, and smoking. The most frequent symptom is rectal bleeding (45%), followed by anal pain, and sensation of a rectal mass. The diagnosis requires clinical examination, palpation of the inguinal lymph nodes, high resolution anoscopy followed by fine-needle aspiration biopsy or core biopsy. Subsequent histologic diagnosis is necessary, as well as computed tomography or magnetic resonance imaging evaluation of the pelvic lymph nodes. Since 1980, patients with a diagnosis of anal cancer have shown a significant improvement in survival. In Europe during the years 1983–1994, 1-year survival increased from 78% to 81%, and the improvement over 5 years was between 48% and 54%. Prior to 1974, patients with invasive cancer were routinely scheduled for abdominoperineal amputation, after which it was demonstrated that treatment with 5-fluorouracil and radiotherapy associated with mitomycin or capecitabine could be adequate to treat the tumour without surgery. Today, numerous studies have confirmed that combined multimodal treatment is effective and sufficient.