Non-surgical management of anal cancer by radiotherapy alone or combined with chemotherapy has, in uncontrolled studies, yielded similar local tumour control and survival rates to surgery. However, whether the addition of chemotherapy improves outcome without adding to morbidity is not known. Our trial was designed to compare combined modality therapy (CMT) with radiotherapy alone in patients with epidermoid anal cancer.

From 856 patients considered for entry to our multicentre trial, 585 patients were randomised to receive initially either 45 Gy radiotherapy in twenty or twenty-five fractions over 4-5 weeks (290 patients) or the same regimen of radiotherapy combined with 5-fluorouracil (1000 mg/m2 for 4 days or 750 mg/m2 for 5 days) by continuous infusion during the first and the final weeks of radiotherapy and mitomycin (12 mg/m2) on day 1 of the first course (295 patients). We assessed clinical response 6 weeks after initial treatment: good responders were recommended for boost radiotherapy and poor responders for salvage surgery. The main endpoint was local-failure rate (> or = 6 weeks after initial treatment); secondary endpoints were overall and cause-specific survival. Analysis was by intention-to-treat.

In the radiotherapy and CMT arms, respectively, five and three were ineligible, and six and nine died 6 weeks after initial treatment. After a median follow-up of 42 months (interquartile range 28-62), 164 of 279 (59%) radiotherapy patients had a local failure compared with 101 of 283 (36%) CMT patients. This gave a 46% reduction in the risk of local failure in the patients receiving CMT (relative risk 0.54, 95% CI 0.42-0.69, p < 0.0001). The risk of death from anal cancer was also reduced in the CMT arm (0.71, 0.53-0.95, p = 0.02). There was no overall survival advantage (0.86, 0.67-1.11, p = 0.25). Early morbidity was significantly more frequent in the CMT arm (p = 0.03), but late morbidity occurred at similar rates.

Our trial shows that the standard treatment for most patients with epidermoid anal cancer should be a combination of radiotherapy and infused 5-fluorouracil and mitomycin, with surgery reserved for those who fall on this regimen.