The impact of obesity on the 30-day morbidity and mortality after surgery for endometrial cancer

Study objectives: To examine the effect of body mass index (BMI) on postoperative 30-day morbidity and mortality after surgery to treat endometrial cancer.

Design: Retrospective cohort study (Canadian Task Force classification II-2).

Setting: National Surgical Quality Improvement Program.

Patients: Patients with endometrial cancer who underwent surgery from 2005 to 2011.

Interventions: Women were grouped according to weight, as follows: normal weight (BMI 18 to <30), obese (BMI 30 to <40), and morbidly obese (BMI ≥ 40). Univariate and multivariable logistic regression models were analyzed.

Measurements and main results: Of 3947 patients, 38% were of normal weight, 38% were obese, and 24% were morbidly obese. Of these, 48% underwent laparoscopy and 52% underwent laparotomy. Overall 30-day morbidity and mortality were 13% and 0.7%, respectively. Obesity and morbid obesity were associated with a higher American Society of Anesthesiologists class, diabetes, and hypertension. Preoperatively, elevated serum creatinine concentration, hypoalbuminemia, and leukocytosis were more common in morbidly obese women than those of normal weight. Laparoscopic surgery was performed less frequently in morbidly obese women than in those of normal weight (42.5% vs 50%; p = .001). Morbidly obese patients were more likely to develop postoperative complications (morbidly obese 16% vs normal weight 13% vs obese 11%; p = .001), in particular surgical (morbidly obese 14% vs normal weight 11% vs obese 9%; p < .001) and infectious complications (morbidly obese 10% vs normal weight 5% vs obese 5%; p = .01). After laparotomy, morbidly obese women demonstrated a higher rate of any complication (normal weight 21%, obese 18%, morbidly obese 25%; p = .002), surgical complications (normal weight 18%, obese 14%, morbidly obese 22%; p = .002) and infectious complications (normal weight 6%, obese 10%, morbidly obese 16%; p < .001). After laparoscopy there was no difference in complication rates according to BMI group. The 30-day mortality was not significantly different according to BMI. After adjusting for confounders, obesity and morbid obesity did not independently predict 30-day morbidity or mortality.

Conclusions: Morbidly obese patients with endometrial cancer have more preoperative morbidities and postoperative complications, in particular surgical and infectious complications, and are less likely to undergo minimally invasive surgery. However, obesity was not an independent predictor of perioperative outcomes after controlling for other confounders.