Body mass index (BMI) influence on Cetuximab-induced antibody-dependent cellular cytotoxicity in advanced colon cancer

To date, we do not know if the excess of the body mass index (BMI) improves or worsens the outcomes in colorectal cancer treatment, and the correlation between BMI and prognosis remains unclear. A recent study in vitro showed a significant negative correlation between BMI and Cetuximab-induced antibody-dependent cellular cytotoxicity. On these bases, we tried to analyze the potential correlation between BMI and survival in patients affected by metastatic colorectal cancer (mCRC) and treated with Cetuximab. Retrospective data were collected from 132 patients affected by mCRC treated with Cetuximab in monotherapy or association with chemotherapy between January 2007 and October 2019. The cohort of patients was divided into different groups according to the World Health Organization (WHO) BMI classification: underweight (BMI < 18.59), normal weight (BMI 18.5–24.9,) overweight (BMI 25–29.9), and obese (BMI > 30), and we observed the influence of BMI on survival and treatment response. Patients with BMI ≥ 25 had statistically significantly better survival than patients BMI < 25 (19 vs 10 months, p = 0.025). Dividing the sample into the four WHO BMI categories, the best survival rates were seen in the overweight and obese subgroups (18 and 26 months respectively, p < 0.01). The multivariate analysis confirmed BMI as the only parameter able to influence survival. No correlation between BMI and treatment response was seen between BMI ≥ 25 and BMI ≤ 24 groups (p = 0.14). Our experience suggests that mild obese and overweight patients treated with Cetuximab could experience a better survival. We also observed that among normal weight, overweight, and mild obese patients, there is a better response to immunochemotherapy in comparison with underweight patients, but this difference does not reach a significative statistical value.