The Reality of Lung Cancer Paradox: The Impact of Body Mass Index on Long-Term Survival of Resected Lung Cancer. A French Nationwide Analysis from the Epithor Database

SIMPLE SUMMARY: It is commonly believed that obesity increases the risk of cancers and lowers the possibility of cure of patients with proven cancers. In recent years, this traditional view has been challenged by the hypothesis of an ‘obesity paradox’, which refers to a better prognosis in obese patients with some specific cancers, compared to normal/underweight patients. In this study, we assessed, in a nationwide dataset, the prognostic role of preoperative BMI on postoperative outcomes in patients undergoing curative lung resection for non-small-cell lung cancer (NSCLC) and found that BMI is a strong and independent predictor of long-term survival. ABSTRACT: Obesity could have a protective effect in patients with lung cancer. We assessed the prognostic role of preoperative BMI on survival in patients who underwent lung resection for NSCLC. A total of 54,631 consecutive patients with resectable lung cancer within a 15-year period were extracted from Epithor (the French Society of Thoracic and Cardiovascular Surgery database). Patient subgroups were defined according to body mass index (BMI): underweight (BMI < 18.5 kg/m(2)), normal weight (18.5 ≤ BMI < 25 kg/m(2)), overweight (25 ≤ BMI < 30 kg/m(2)), and obese (BMI ≥ 30 kg/m(2)). Underweight was associated with lower survival (unadjusted HRs 1.24 (1.16–1.33)) compared to normal weight, whereas overweight and obesity were associated with improved survival (0.95 (0.92–0.98) and 0.88 (0.84–0.92), respectively). The impact of BMI was confirmed when stratifying for sex or Charlson comorbidities index (CCI). Among patients with obesity, a higher BMI was associated with improved survival. After adjusting for period of study, age, sex, WHO performance status, CCI, side of tumor, extent of resection, histologic type, and stage of disease, the HRs for underweight, overweight, and obesity were 1.51 (1.41–1.63), 0.84 (0.81–0.87), and 0.80 (0.76–0.84), respectively. BMI is a strong and independent predictor of survival in patients undergoing surgery for NSCLC.