The impact of anthropometric parameters on colorectal cancer prognosis: A systematic review and meta-analysis.

Background & Aims: Our study aims to clarify the relationship between weight parameters and colorectal cancer outcomes.

Methods: NCBI, Embase, Cochrane, and Web of Science were searched from inception to December 2019. Studies reporting colorectal cancer (CRC) mortality, recurrence, disease-free survival, overall survival, overall mortality stratified by pre-diagnosis BMI or post-diagnosis weight change, were included in the analysis. Random effects analysis was performed for all outcomes, with heterogeneity assessed by the I statistic.

Results: Our meta-analysis included 45 studies encompassing 607,266 patients. Obesity was associated with increased odds of overall mortality and CRC-specific mortality compared to normal weight (p < 0.001). Patients with underweight BMI had increased odds of CRC-specific mortality compared to normal BMI but were not significantly different from obese BMI.

Conclusions: Obese and underweight BMI are associated with increased CRC-specific and overall mortality compared to normal BMI. Long term prognosis was similar for patients with obese and underweight BMI.