Combined Therapy Information from clinical trials supports the idea of using chemotherapy plus radiotherapy for the initial treatment of epidermoid cancer of the anus, reserving surgery for residual disease. External radiation therapy with chemotherapy is now the first line of therapy and results in 80 percent to 90 percent local control. One clinical trial has shown that the combination of radiation plus 5-fluorouracil (5-FU) and mitomycin-C is more effective in preserving anal function than radiation alone. Another trial showed that the combination of 5-FU and mitomycin-C with radiation was better than 5-FU alone. Another effective combination now being used is radiation with 5-FU + cisplatin .
Even when all the tumor is eradicated by radiation and chemotherapy, careful follow-up is vital. The most common sites of local recurrence are in the pelvis at the site of the primary tumor and in regional lymph nodes . If the tumor recurs, salvage surgery will be needed.
Adenocarcinoma Treatment of the less common adenocarcinoma involving the upper portion of the anus (near the rectum) differs from treatment of squamous carcinoma . For smaller lesions, local excision or fulguration may occasionally suffice. In selected cases, interstitial implants of iridium with external radiation therapy may be an alternative. For larger lesions, an abdominal-perineal resection may be required. Combined radiotherapy and chemotherapy is not as useful, although adjuvant chemotherapy and radiotherapy programs to supplement surgery can be employed.
