Differences in treatment and survival rates of non-small-cell lung cancer in three regions of France.

Treatment and survival rates of patients with non-small-cell lung cancer (NSCLC) were compared between three French Cancer Registries (Calvados, Doubs, Tarn). The methodological issues in such comparisons are discussed. The treatments for NSCLC differed between the regions: radiotherapy tended to be preferred in Calvados (73% vs 21.3% surgery), whereas surgery was more frequently employed in Doubs and Tarn (27.7% and 37% respectively). The percentage of cases receiving no therapeutic treatment ranged from 7.8% (Calvados) to 26% (Tarn). Despite the differences in treatment, the overall survival rates were similar in the three regions. Adjustment for treatment in such a descriptive study may be misleading since different therapeutic strategies in different regions may lead to selection of patients of systematically better or poorer prognosis in the various treatment groups.