Operative Risk for Major Lung Resection Increases at Extremes of Body Mass Index

Abstract

Background Although body mass index (BMI) has been used in risk stratification for lung resection, many models only take obesity into account. Recent studies have demonstrated that underweight patients also experience increased postoperative complications. We explored the relationship of extremes of BMI to outcomes after lung resection for non-small cell cancer. Methods Patients in the Society of Thoracic Surgeons General Thoracic Surgery Database (2009 to 2014) undergoing elective lung resection for cancer were evaluated. Multivariable logistic regression was used to adjust for potential confounders including functional status and spirometry. Results We evaluated 41,446 patients (median 68 years of age; 53% female) grouped by BMI: underweight (<18.5 kg/m2; 3.0%), normal (18.5 to 24.9 kg/m2; 33.5%), overweight (25 to 29.9 kg/m2; 35.4%), obese I (30 to 34.9 kg/m2; 18.1%), obese II (35 to 39.9 kg/m2; 6.4%), and obese III (≥40 kg/m2; 3.6%). Pulmonary complication rates were higher in underweight and obese III patients compared to normal BMI patients (p < 0.001). On multivariable analysis, compared to patients with normal BMI, being underweight was associated with an increased risk of pulmonary complications (adjusted odds ratio [OR]: 1.41, 95% confidence interval [CI]: 1.16 to 1.70) and any postoperative event (adjusted OR: 1.44, 95% CI: 1.26 to 1.64). Obese III patients had an increased risk of any major postoperative complication (adjusted OR: 1.18, 95% CI: 1.02 to 1.36). Overweight and obese class I to II patients had a lower risk of pulmonary complications and any postoperative event. Conclusions BMI is associated with postoperative complications after lung resection for cancer. Being underweight or severely overweight is associated with an increased risk of complications, whereas being overweight or moderately obese appears to have a protective effect.

Body Mass Index (BMI), BMI Change, and Overall Survival in Patients With SCLC and NSCLC: A Pooled Analysis of the International Lung Cancer Consortium

“…[36][37][38][39] Secondly, past studies have not assessed the role of morbid obesity (defined as BMI > 40 kg/m 2 ) on survival, but have focused on complication rates in both obese and morbidly obese patients. 17,40,41 This is an important knowledge gap, as the only available data suggest that all overweight and obese patients have improved survival regardless of the magnitude of the BMI value. Thirdly, prior analyses have mostly assessed the prognostic role of BMI captured at the time of diagnosis, but have not evaluated BMI in a patients' prior healthy state.…”

Obesity Paradox in Lung Cancer Prognosis: Evolving Biological Insights and Clinical Implications

“…Indeed, a very recent analysis of 41,446 patients who underwent lung resection for cancer shows that being underweight or severely overweight is associated with an increased risk for complications. 28 Therefore, obesity is more likely to have a protective effect on lung cancer outcome in patients with a BMI approximating those indicating overweight or normal obesity.…”

Prediction of Long-Term Survival After Lung Cancer Surgery for Elderly Patients in The Society of Thoracic Surgeons General Thoracic Surgery Database

“…BMI is another modifiable risk factor. Short-term analysis has demonstrated increased risk of perioperative events at the extremes of BMI [16]. Underweight patients (BMI < 18.5) maintain significantly increased risk (hazard ratio [HR] 1.58) independently over time.…”