Sarno Gerardo, Simancas-Racines Daniel, Gargiulo Antonio, Tedesco Anna, Iacone Biancamaria, Reytor-González Claudia, Parise-Vasco Juan Marcos, Iguago Jaime Angamarca, Sarno Sabrina, Frias-Toral Evelyn, Bracale Umberto
General Surgery and Kidney Transplantation Unit - "San Giovanni di Dio e Ruggi D'Aragona" University Hospital, Scuola Medica Salernitana, Salerno 84131, Italy; General and Emergency Surgery Unit, Department of Medicine, Surgery and Dentistry, "Salerno Medical School", San Giovanni di Dio e Ruggi d'Aragona University Hospital, Scuola Medica Salernitana, University of Salerno, Faculty of Medicine and Surgery, Campus di Baronissi (SA), "Gaetano Fucito" Facility, Mercato San Severino, Salerno, SA, Italy.
Universidad UTE, Facultad de Ciencias de la Salud Eugenio Espejo, Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC), Quito 170527, Ecuador.
Semin Cancer Biol. 2025 Aug;113:176-189. doi: 10.1016/j.semcancer.2025.05.012. Epub 2025 May 22.
Obesity has been increasingly recognized as a factor that influences postoperative outcomes in colorectal cancer surgery. However, its impact on surgical complications, mortality, and oncological outcomes remains controversial. This systematic review and meta-analysis aimed to evaluate the association between obesity and postoperative complications in colorectal cancer surgery.
A comprehensive search was conducted in MEDLINE/PubMed, Scopus, and Embase, including studies evaluating body mass index (BMI) in relation to postoperative complications such as infections, anastomotic leakage, postoperative ileus, bleeding, reoperation, and mortality. Data synthesis involved a qualitative analysis of all eligible studies and a meta-analysis when applicable. The quality of the studies included was assessed using the Newcastle-Ottawa Scale, while the certainty of evidence was evaluated through the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.
Twenty-nine studies were included in the qualitative analysis and 17 were eligible for the meta-analysis. Compared to BMI < 30 kg/m², patients with BMI ≥ 30 kg/m² showed significantly higher risk of any type of surgical site infection (OR=1.49; 95 % CI: 1.37-1.70; low certainty). No significant differences were found in mortality (OR=1.23; 95 % CI: 0.72-2.11; very low certainty), hemorrhage (OR=1.05; 95 % CI: 0.97-1.14; very low certainty), or gastrointestinal complications (OR=1.10; 95 % CI: 0.96-1.26; very low certainty).
Obesity significantly increases the risk of surgical site infections in colorectal cancer surgery. Although its impact on mortality and gastrointestinal complications remains unclear, implementing preoperative optimization protocols specifically aimed at obesity management could mitigate these surgical risks. The certainty of evidence ranges from low to very low, highlighting the need for high-quality prospective studies with standardized BMI criteria and surgical protocols.
