ABSTRACT: This study is an analysis of the criteria considered when prescribing concomitant chemotherapy and radiotherapy, as a routine treatment for patients with anal canal cancer, and related complications. Between 1990 and 1996, 67 patients were treated at Institut Curie for invasive, nonmetastatic cancer of the anal canal. Median age was 65 years (range, 35-90 years). TNM stage distribution was as follows: seven T1, 17 T2, 27 T3, 16 T4, and 22 N+ patients. A total of 29 patients (i.e., five T1/T2, and 24 T3/T4) received concurrent chemotherapy and radiotherapy. Radiotherapy volumes and dose and prescribed dose for chemotherapy were not statistically different from one group of patients to another. Only 55% of T3/T4 patients underwent standard chemoradiation treatment for anal canal cancer. Age was the one of main factor in determining if the patient would undergo concomitant chemotherapy or not. For the T3/T4 patients, concomitant chemotherapy was prescribed to 69% of patients <55 years, 90% of patients between 56 and 64 years, 45% of patients between 65 and 75 years, and 20% of patients over 75 years (P<0.02). Overall survival at 4 years was 66%. The 4 years overall survival rate of T3/T4 patients, who underwent concomitant chemotherapy, was 72%, and that of T3/T4 patient who did not, was 34% (P<0.04). The patients who did not undergo chemotherapy were significantly older. The difference in cause-specific survival rates (72 vs 48%) was not significant. Relapse-free interval without local recurrence at 4 years was 70%. Relapse-free interval of T3/T4 patients was 78% with chemotherapy and 60% without chemotherapy (p=NS). Rates of treatment discontinuation and early toxicity were not statistically different. Late complications occurred in 33 patients, eight of whom had grade 2/3 tumours. At 2 years, complications occurred in 39% of patients who had undergone concomitant chemotherapy, and in 20% of patients who had not (p<0.02). Differences in grade 2/3 complications were not significant. In conclusion, although radiotherapy with concomitant chemotherapy is considered the current 'gold-standard' treatment for anal canal cancer, in our daily experience, only 55% of our T3/T4 patients have undergone this treatment. The remainder did not undergo chemotherapy mainly because they were deemed too old. In this series, no increase in local control and cause-specific survival was observed in patients who received concomitant chemotherapy; this may be due to the small number of patients included in the series. The increased rate of late complications observed in patients who received the combined treatment, however, provides evidence that this treatment should be restricted to younger patients without comorbidity and therefore justifies our position. Perhaps reduction of doses of chemotherapy must be discussed for older patients.
