Effect of Body Mass Index on 5-FU-Based Chemotherapy Toxicity and Efficacy Among Patients With Metastatic Colorectal Cancer; A Pooled Analysis of 5 Randomized Trials

Abstract

Introduction: We conducted this study to assess the effect of baseline body mass index (BMI) on the toxicity and efficacy of systemic chemotherapy among patients with metastatic colorectal cancer (CRC).

Patients and methods: This was a pooled analysis of 5 clinical trials (NCT00115765, NCT00364013, NCT00272051, NCT00305188, and NCT00384176), which were accessed from the Project Data Sphere (www.projectdatasphere.org) platform. Multivariable logistic regression analysis was used to assess the relationship between BMI and the probability of different toxicities. Kaplan-Meier survival estimates were used to assess the effect of BMI on overall and progression-free survival. Multivariable Cox regression analysis was additionally conducted to evaluate the effect of BMI on overall and progression-free survival.

Results: A total of 3155 patients were included in the current analysis. Within multivariable logistic regression analysis, higher BMI was associated with higher probability of all-grade nausea and vomiting (odds ratio [OR], 1.025; 95% confidence interval [CI], 1.009-1.042; P = .002) and peripheral neuropathy (OR, 1.018; 95% CI, 1.001-1.034; P = .036; analysis restricted to oxaliplatin-treated patients). Lower BMI was associated with a higher probability of all-grade anemia (OR, 0.975; 95% CI, 0.956-0.995; P = .015), high-grade anemia (OR, 0.941; 95% CI, 0.890-0.994; P = .030), all-grade neutropenia (OR, 0.983; 95% CI, 0.968-0.999; P = .034), and high-grade neutropenia (OR, 0.962; 95% CI, 0.945-0.979; P < .001). Higher BMI also seemed to correlate with better overall survival in a multivariable Cox regression model (hazard ratio as a continuous variable: 0.977; 95% CI, 0.967-0.988; P < .001).

Conclusion: Lower BMI was associated with a higher risk of hematological toxicities (anemia and neutropenia) whereas higher BMI might be associated with a higher risk of nausea, vomiting, and peripheral neuropathy. Higher BMI also seemed to be associated with better overall survival among patients with metastatic CRC.

Keywords: BMI; CRC; Colon cancer; Prognosis; Rectal cancer.