A structured preoperative weight loss program is both safe and feasible for adults preparing for colorectal cancer (CRC) surgery, according to a new UK study. Patients following a low-calorie, high-protein diet lost a median of 6.1 kg before surgery, maintained muscle mass, and experienced improvements in postoperative symptoms such as fecal incontinence and skin issues.
Early analyses also suggest the program may be cost-effective, supporting its potential for wider clinical use. The findings are published in JAMA Network Open.
“In this randomized clinical trial, an intensive weight loss intervention was feasible and safe for patients with excess weight awaiting colorectal cancer surgery,” the researchers wrote. “Participants lost weight without compromising fat-free mass and reported fewer postoperative symptoms compared with standard care.”
Preoperative weight loss in CRC patients is complex. Both excess weight and unintended weight loss can affect surgical outcomes. Previous research indicated that losing more than 3% of body weight in the six months before surgery was linked to delayed recovery and higher 60-day readmission rates, highlighting the risks of malnutrition.
The CARE study, an assessor-blinded, randomized clinical trial, ran from March 2023 to August 2024 across eight hospitals in England. Adults with a body mass index (BMI) of 28 or higher scheduled for elective, curative CRC surgery were eligible. Participants were randomized to either standard care or a preoperative low-energy total diet replacement program providing 800 kcal/day and 76 g/day of protein, with dietetic support delivered via telephone.
Primary outcomes measured feasibility, including recruitment, engagement with dietitian calls, adherence to weight loss targets, and retention. Secondary outcomes assessed postoperative morbidity, symptoms, and changes in weight and fat-free mass, while longer-term health and cost-effectiveness were modeled over a 30-year horizon.
Of 150 patients approached, 71 were randomized (36 intervention, 35 usual care), with a mean age of 64 years and mean BMI of 35.4. Intervention participants attended 85% of dietetic calls, and 61% achieved at least 5% weight loss before surgery, compared with 9% in the usual care group. On average, intervention participants lost 6.1 kg, 4.3 kg more than those receiving usual care, with negligible change in fat-free mass.
Overall postoperative complications were similar between groups (39% vs 40%). However, patients in the intervention group saw improvements in fecal incontinence and skin soreness. Exploratory analyses indicated that participants losing 3.2% or more of their body weight experienced a 50% relative reduction in complications, and cost-effectiveness modeling favored the intervention.
The researchers noted several limitations. Usual care participants lost around 2 kg preoperatively, likely due to trial participation, and study participants were generally fitter than typical CRC patients. Weekly dietitian contact may have increased minor adverse event reporting. Future studies should include frailer patients and use more sensitive endpoints, such as the Comprehensive Complication Index.
Despite these limitations, the study shows that a low-energy total diet replacement program before CRC surgery is feasible, safe, and well tolerated. It achieves significant weight loss without compromising muscle mass and may improve postoperative outcomes.
“An intensive preoperative weight loss intervention was safe, feasible, and likely cost-effective as part of prehabilitation before colorectal cancer surgery, with evidence of improvements in key postoperative symptoms,” the researchers concluded.
Related topic：
