Retrospective Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jul 15, 2022; 14(7): 1324-1336
Published online Jul 15, 2022. doi: 10.4251/wjgo.v14.i7.1324
Effect of obesity on post-operative outcomes following colorectal cancer surgery
Derek Mao, David E Flynn, Stephanie Yerkovich, Kayla Tran, Usha Gurunathan, Manju D Chandrasegaram
Derek Mao, Faculty of Medicine and Health, The University of Sydney, Sydney 2050, New South Wales, Australia
David E Flynn, Manju D Chandrasegaram, Department of General Surgery, The Prince Charles Hospital, Brisbane 4032, Queensland, Australia
Stephanie Yerkovich, Usha Gurunathan, Manju D Chandrasegaram, Faculty of Medicine, The University of Queensland, Brisbane 4006, Queensland, Australia
Kayla Tran, Department of Pathology, The Prince Charles Hospital, Brisbane 4032, Queensland, Australia
Usha Gurunathan, Department of Anaesthesia, The Prince Charles Hospital, Brisbane 4032, Queensland, Australia
Author contributions: Mao D designed the study, performed the research, and wrote the manuscript; Flynn DE designed the study methodology and helped perform the research; Yerkovich S helped with data collection, statistical analysis, and manuscript review; Tran K and Gurunathan U helped with data collection, clinical advice, data analysis, and manuscript review; Chandrasegaram MD helped with design methodology and conceptualization, study supervision, manuscript editing and finalization.
Institutional review board statement: Ethics approval for this database was granted by the Prince Charles Hospital Human Research Ethics Committee (Approval No. HREC/17/QPCH/295).
Informed consent statement: I certify that patients were not required to give informed consent to the study because the analysis used anonymous clinical data that was obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Manju D Chandrasegaram, FRCS, MBChB, Attending Doctor, Senior Lecturer, Surgeon, Department of General Surgery, The Prince Charles Hospital, Rode Road, Brisbane 4032, Queensland, Australia.
Received: November 22, 2021
Peer-review started: November 22, 2021
First decision: December 27, 2021
Revised: January 10, 2022
Accepted: June 18, 2022
Article in press: June 18, 2022
Published online: July 15, 2022

Colorectal cancer (CRC) resection is currently being undertaken in an increasing number of obese patients. Existing studies have yet to reach a consensus as to whether obesity affects post-operative outcomes following CRC surgery.


To evaluate the post-operative outcomes of obese patients following CRC resection, as well as to determine the post-operative outcomes of obese patients in the subgroup undergoing laparoscopic surgery.


Six-hundred and fifteen CRC patients who underwent surgery at the Prince Charles Hospital between January 2010 and December 2020 were categorized into two groups based on body mass index (BMI): Obese [BMI ≥ 30, n = 182 (29.6%)] and non-obese [BMI < 30, n = 433 (70.4%)]. Demographics, comorbidities, surgical features, and post-operative outcomes were compared between both groups. Post-operative outcomes were also compared between both groups in the subgroup of patients undergoing laparoscopic surgery [n = 472: BMI ≥ 30, n = 136 (28.8%); BMI < 30, n = 336 (71.2%)].


Obese patients had a higher burden of cardiac (73.1% vs 56.8%; P < 0.001) and respiratory comorbidities (37.4% vs 26.8%; P = 0.01). Obese patients were also more likely to undergo conversion to an open procedure (12.8% vs 5.1%; P = 0.002), but did not experience more post-operative complications (51.6% vs 44.1%; P = 0.06) or high-grade complications (19.2% vs 14.1%; P = 0.11). In the laparoscopic subgroup, however, obesity was associated with a higher prevalence of post-operative complications (47.8% vs 39.3%; P = 0.05) but not high-grade complications (17.6% vs 11.0%; P = 0.07).


Surgical resection of CRC in obese individuals is safe. A higher prevalence of post-operative complications in obese patients appears to only be in the context of laparoscopic surgery.

Keywords: Colorectal cancer, Obesity, Body mass index, Post-operative outcomes, Clavien-Dindo

Core Tip: This retrospective study assessed the post-operative outcomes of obese patients undergoing colorectal cancer (CRC) resection. Despite having a greater burden of cardiovascular and respiratory comorbidities and increased rate of conversion to open surgery, obese patients had equitable post-operative outcomes as those with a normal body mass index. There were no differences in severity of complications, length of stay, or mortality rates. Comparisons of obese and non-obese patients undergoing laparoscopic surgery showed that obese patients had a higher prevalence of post-operative complications but not high-grade complications. CRC surgery in obese individuals is generally safe, with caution advised if a laparoscopic approach is planned.