The anal canal is the final part of the digestive tract, ranging in size from 3 to 4 cm, located between the rectum and the skin of the anal edge.
Cancer of the anal canal is rare, prevails in women. Two thirds of patients are over 65 years old.
Risk factors are multiple sexual relations with different partners, human papillomavirus (16 and 18) and HIV infection, immunosuppression, and smoking.
Epidermoid cancer of the anal canal accounts for 95% of cancers of the anal canal.
In recent years, treatment has been carried out in such a way as to preserve the sphincter and its functions. For this, radiotherapy is used in conjunction with concomitant chemotherapy for large tumors.
Clinical examination includes pelvic (rectal) examinations. A proctoscopy with a biopsy is important in the diagnosis. An additional examination is an MRI of the pelvis and PET with 18 FDG to assess the presence or absence of the affected inguinal or pelvic lymph nodes and / or metastases.
Radiotherapy of 59.4 Gy for 33 sessions of 1.8 Gy on a tumor and pathological lymph nodes, together with chemotherapy of the 5FU type and mitomycin C (2 cycles), allows you to save the sphincter of the anal canal and avoid surgical intervention and amputation of the sphincter. The evaluation is carried out after 8 weeks with clinical examination, proctoscopy, a full biological evaluation with a tumor marker SCC and visualization (MRI of the pelvis and / or PET scan), while monitoring is carried out every three months in the first year after treatment.