Obesity has been associated with an increased risk of colorectal cancer especially in men where there is a 30-70% increased risk. This association has not been entirely consistent in women. The risk is thought to be due to molecular and metabolic effects on insulin, adipocytokines, IGF-1, and sex hormones.
The objective of this study was to assess the impact of obesity on three outcomes of surgery: wound infection rates, formation of pelvic abscess and local recurrence rates.
A retrospective analysis of patients that underwent elective colorectal cancer surgery at the Townsville hospital between the first of January 2010 and 31st of December 2015 was made. The patients were included if they had an operation with curative intent. Patients who had emergency surgery, previous malignancy, metastatic disease or no recorded BMI were excluded.
521 patients were analysed. 24% were in the BMI of less than 25kg/m2 group, 42 %kg/m2 were in the BMI of 25-30kg/m2 group, and 34 % were in the BMI of more than 30kg/m2 group. Obesity was associated with higher wound infection rates, 9.5% in the BMI less than 25kg/m2 group. 12% in the 25-30kg/m2 group and 14.6% in the above 30kg/m2 group. Pelvic abscesses were also correlated with obesity with 32 percent in the BMI less than 25kg/m2 group, 34% in the BMI 25-30kg/m2 group and 35% in the BMI greater than 30kg/m2 group. Local recurrence rates did not show a correlation with obesity. The local recurrence rates were 14% in the BMI less than 25kg/m2, 10.5% in the BMI 25-30Kg/m2 and 13,5 % in the BMI greater than 30kg/m2.
Obesity was associated with increased wound infection rates and and pelvic abcess rates. The local recurrence rates were however not correlated to obesity in this regional centre.