National perioperative outcomes of pulmonary lobectomy for cancer: the influence of nutritional status.

OBJECTIVES: Nutritional assessment is not included yet as a major recommendation in lung cancer guidelines. The purpose of this study was thus to assess the influence on surgical outcome of the nutritional status of patients with primary lung cancer undergoing lobectomy.
METHODS: We queried Epithor, the national clinical database of the French Society of Thoracic and Cardiovascular Surgery, and identified a retrospective cohort of 19 635 patients having undergone lobectomy for a primary lung cancer in the years 2005-11. Their nutritional status was categorized according to the WHO definition: underweight (BMI < 18.5): 857 patients (4.4%), normal (18.5 ≤ BMI < 25): 9391 patients (47.8%), overweight (25 ≤ BMI < 30): 6721 patients (34.2%), obese (BMI ≥ 30): 2666 patients (13.6%). Operative mortality, pulmonary, cardiovascular, infectious and surgical complications rates were collected and analysed for these various BMI groups.
RESULTS: In the normal-weight category, operative mortality, pulmonary, surgical, cardiovascular and infectious complications rates were 2.7, 14.6, 13.8, 5.5 and 4.1%, respectively. When compared with that of normal BMI patients, adjusted operative mortality was significantly lower in overweight (2.3%; odd ratio (OR): 0.72 [95% confidence interval (CI): 0.59-0.89]; P = 0.002) and obese patients (1.9%, OR: 0.54 [95% CI: 0.40-0.74]; P < 0.001), and significantly higher in underweight patients (4.1%, OR: 1.89 [95% CI: 1.30-2.75]; P = 0.001). Underweight patients experienced significantly more pulmonary (21.1%; P < 0.001), surgical (23.2%; P < 0.001) and infectious (5.1%; P = 0.05) complications (P < 0.0001). Among surgical complications, prolonged air leaks (17.6%; P < 0.001) and bronchial stump dehiscence (1.5%; P = 0.001) were significantly more frequent in underweight patients than in normal BMI patients. Obesity was not associated with increased incidence of postoperative complications, except for arrhythmia (5.6%; P < 0.05), deep venous thrombosis and pulmonary embolism (1.5%; P = 0.005). Moreover, a statistical protective effect of obesity was observed regarding surgical complications (7.1%; P < 0.001).
CONCLUSIONS: Despite having an increased risk of some postoperative cardiovascular complications, obese patients should undergo surgical standard of care therapy for appropriately stage-specific lung cancer. In underweight patients, in addition to preoperative rehabilitation including a nutritional program, attention should be given to aggressive prophylactic respiratory therapy in the perioperative period, and specific intraoperative actions to prevent prolonged air leaks and bronchial stump dehiscence.