Influence of body mass index on outcomes after major resection for cancer.

BACKGROUND: Evidence supporting worse outcomes among obese patients is inconsistent. This study examined associations between body mass index (BMI) and outcomes after major resection for cancer.

METHODS: Data from the 2005-2012 ACS-NSQIP were used to identify cancer patients (≥18 years) undergoing 1 of 6 major resections: lung surgery, esophagectomy, hepatectomy, gastrectomy, colectomy, or pancreatectomy. We used crude and multivariable regression to compare differences in 30-day mortality, serious and overall morbidity, duration of stay, and operative time among 3 BMI cohorts defined by the World Health Organization: normal versus underweight, overweight-obese I, and obese II-III. Propensity-scored secondary assessment and resection type-specific stratified analyses corroborated results.

RESULTS: A total of 529,955 patients met inclusion criteria; 32.06% had normal BMI, 3.45% were underweight, 32.52% overweight, and 17.76%, 7.51%, and 4.94% obese I-III, respectively. Risk-adjusted outcomes for underweight patients consistently were worse. Overweight-obese I fared similarly to patients with normal BMI but had greater odds of isolated complications. Obese II-III patients experienced only marginally increased odds of morbidity. Analyses among propensity-scored cohorts and stratified by cancer-resection type reported similar trends. Worse outcomes were observed among morbidly obese hepatectomy and pancreatectomy patients.

CONCLUSION: Evidence-based assessment of outcomes after major resection for cancer suggests that obese patients should be treated with the aim for optimal oncologic standards without being hindered by a misleading perception of prohibitively increased perioperative risk. Underweight and certain types of morbidly obese patients require targeted provision of appropriate care.