Prognosis of rectal cancer in France.

We studied changes in the prognosis of cancer of the rectum (excluding the rectosigmoid junction) from 1978 to 1986 in the French department of Calvados on the basis of the 616 cases in the cancer registry. Taken as whole, survival has improved slightly with time (P < 0.01), but the improvement is only significant for men (P < 0.02), patients under 70 years (P < 0.01) and patients living in urban areas (P < 0.05). With regard to tumour characteristics, the improvement was significant only for patients with Dukes' stage C tumours at surgery (P < 0.02). To determine the reasons for the improvement in survival, the year of diagnosis and all other prognostic factors were studied in a multivariate model. Diagnostic conditions such as age and tumour stage did not vary from 1978 to 1986; in contrast, the rates of tumour resection and adjuvant radiation therapy increased, possibly explaining at least part of the improvement, particularly for patients with Dukes' stage C tumours.