The effect of increased body mass index values on surgical outcomes after radical resection for low rectal cancer.

PURPOSES: This study aimed to explore the effect of increased body mass index (BMI) values (overweight: BMI ≥ 25-30 kg/m2 ; obese: BMI ≥ 30 kg/m2 ) on surgical outcomes after radical resection for low rectal cancer (LRC).

METHODS: Patients with LRC who underwent radical surgery from January 2009 to December 2013 were included. The patients were divided into three groups according to their BMI values (control group: BMI < 25 kg/m2 ; overweight group: BMI 25 to < 30 kg/m2 ; obese group: BMI ≥ 30 kg/m2 ). The patients' clinicopathological characteristics and survival data were collected and analyzed.

RESULTS: A total of 792 patients were enrolled in this study finally (control, n = 624; overweight, n = 147; obese, n = 21). The baseline characteristics of the three groups were similar. We found that an increased BMI was associated with a longer operative time (P < 0.001) and length of postoperative hospital stay (P = 0.032). Patients with increased BMI values had a significantly higher incidence of postoperative complications, including pulmonary infection (P = 0.008), anastomotic leakage (P = 0.029), allergy (P = 0.017) and incisional hernia (P = 0.045). The limited data showed that the pathological outcomes of the three groups did not differ to a statistically significant extent. A multivariate analysis showed that increased BMI was not associated with poorer OS or DFS.

CONCLUSION: In LRC resection, an increased BMI was associated with a longer operative time, postoperative hospital stay, and an increased number of postoperative complications. However, it did not contribute to poorer pathological or survival outcomes.