Hospital volume: operative morbidity, mortality and survival in thoracotomy for lung cancer. A Spanish multicenter study of 2994 cases.

INTRODUCTION: It has been hypothesized that medical procedures performed in high-volume units carry less risk and achieve a better outcome. OBJECTIVE: To determine the relationship between the number of interventions and the operative morbidity, mortality and long-term survival in the surgery of bronchogenic carcinoma (BC). PATIENTS AND METHOD: Prospective, multicenter Spanish study was conducted in 19 departments of thoracic surgery on 2994 patients operated on consecutively with the aim of curing BC. The thoracic surgery departments have been classified into three groups, according to the number of interventions performed per year: I (1-43 cases/year; centers=7; n=565; 18.9%), II (44-54 cases/year; centers=6; n=1044; 34.9%) and III (55 or more cases/year; centers=6; n=1385; 46.3%). RESULTS: When the three groups were compared, the frequency of complete surgery was found to be 84% for group I, 76% for group II and 83% for group III (p=0.001, for comparisons between groups I/II and II/III). The pathological stages were identical in the three groups. The overall morbidity and the mortality in all patients or above the age of 75 or in pneumonectomies were not different among the groups. When considering all the patients with prognostic information (n=2758), no differences were found regarding the 5-year survival among the groups. When only patients in postoperative stage I-II and complete resection were evaluated, excluding operative mortality (n=1128), 5-year survival was 0.58 for group I, 0.57 for group II and 0.50 for group III (p=0.06 between groups II and III; p=0.08 between groups I and III). CONCLUSIONS: No significant differences that do not favor the hypothesis that there is increased surgical risk and worse survival in centers having a lower volume were found in this Spanish multicenter study.