Severe weight loss during preoperative chemoradiotherapy compromises survival outcome for patients with locally advanced rectal cancer.

PURPOSE: In addition to tumor factors, poor nutritional status before and during anti-tumor treatment might compromise prognosis in several types of cancer. This study was done to determine the impact of weight loss during preoperative chemoradiotherapy (CRT) on the survival outcome of patients with locally advanced rectal cancer (LARC).

METHODS: The retrospective study examined consecutive patients with LARC who underwent preoperative CRT followed by radical resection in a single institute, between 2003 and 2013. Correlation of proportional body mass index (BMI) change after preoperative CRT and patient's demographics, tumor characteristics, treatment parameters, CRT-related toxicity, disease-free survival (DFS) and overall survival (OS) were investigated.

RESULTS: A total of 364 patients were enrolled, and BMI loss was found in 243 patients (66.2 %) after preoperative CRT. Severe weight loss (SWL) was defined as BMI loss ≥7 %. Thirty-nine (10.7 %) cases were enrolled in SWL cohort and found to have higher incidence of diarrhea (P = 0.033), renal disorder (P = 0.033) and grade 3-4 radiation proctitis (P = 0.041). Although no significant difference was found in 3-year DFS, patients in SWL cohort showed significantly worse 3-year OS rate (71.8 vs 88.0 %, P = 0.030) than the others. In univariate analysis, BMI loss ≥7 %, completed dose of preoperative chemotherapy, pathologic T and N stages were correlated with OS (all P < 0.05). In multivariable analysis, BMI loss ≥7 % (HR 1.984; 95 % CI 1.061-3.709; P = 0.032) remained the independent prognostic factor for OS.

CONCLUSIONS: Our results demonstrate that SWL during preoperative CRT indeed compromises survival outcome in patients with LARC. Routine nutritional monitoring and nutritional support during preoperative CRT are suggested as the integral part of the multidisciplinary approach for these patients.