During the past ten years, substantial progress has been made in the knowledge of the natural history of epidermoid carcinoma of the anal canal and of the response of the disease to radiotherapy alone or combined with chemotherapy. At the present time, the main problem in the management of this tumor concerns identification of the best modalities to achieve local control and preservation of anal function. From a series of 276 cases, followed for more than three years, the necessity for a careful pretreatment evaluation was stressed. This included a systematic search for pelvic metastatic lymph nodes by palpation and CT scan. All patients were treated initially by irradiation except those who underwent groin dissection for inguinal node metastasis or colostomy for complete anal obstruction. Three groups of patients have been identified: unresectable or disseminated tumors (33 cases), resectable tumors but not suitable for sphincter conservation (21 cases) treated by radiochemotherapy and delayed surgery, and resectable tumors suitable for sphincter conservation (222 cases) which were treated by a split-course regimen combining a short course of carefully planned external beam irradiation (19 days) followed by an iridium 192 implant after a two-month rest. In this group, which represents 80 percent of the whole series, 80 percent of patients have had their cancer controlled and 90 percent of controlled patients have retained normal anal function. The use of chemotherapy during the first days of irradiation is advisable in all cases to reinforce the efficacy of treatment and increase the chance of anal preservation. Results of the split-course regimen, combining external beam and interstitial irradiation, demonstrate a clear superiority over external beam irradiation alone, especially for large infiltrating tumors, which represent the majority of cases.

The study of 54 patients treated curatively by irradiation with or without surgery is reported. The crude and cancer-specific five-year survival rates are 59.2 percent and 79.7 percent. Three patients were treated palliatively. The great variation in histologic type, clinical appearance, disease stage, and patient status justifies the definition of a treatment strategy using radiotherapy, surgery, or a combination of the two methods. T1 and T2 squamous- or basal-cell carcinomas are suitable for local excision followed by irradiation or for irradiation alone. T3 tumors and Bowen's disease should be treated by irradiation first. Verrucous carcinoma is suitable for local surgery followed by irradiation. Mucoepidermoid carcinoma and T4 tumors are suitable for preoperative irradiation and delayed surgery. The optimal radiation technique consists of delivering a dose of 40 Gy in 17 days by cobalt-60 with bolus and in combination with concomitant chemotherapy (5-fluorouracil and mitomycin C). Prophylactic irradiation of the inguinal area is recommended in all NO tumors except for T1 lesions and basal-cell carcinomas.

Until recently most squamous cell carcinomas of the anal canal were treated by radical surgery. Radiation therapy was only considered for palliation in case of inoperable tumors. Important progress has been made in the knowledge of the natural history of the disease and in the field of radiotherapy. Anal canal squamous cell carcinoma should not be treated any longer by the same procedure as adenocarcinoma of the lower rectum, because both these diseases differ markedly. Multimodality therapy with radiotherapy as first approach has been considered. This series of 121 cases treated since 1971 and followed more than three years suggests that three protocols based on irradiation followed or not by surgery should be used according to the extent of the disease. Of the 72 patients with resectable tumor, the five‐year survival rate was 65%. Three‐quarters of the patients cured had normal anal function. The rate of death from cancer was 18%. The method requires an accurate assessment of the extent of the tumor and of its pelvic lymphatic spread. Great care must be taken in planning treatment in a close cooperation between radiotherapist and surgeon.

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