Role of Metformin in Enhancing Response to Neoadjuvant Chemo-Radiotherapy in Patients with Locally Advanced Rectal Carcinoma

Abstract

Background: Metformin may improve response to concomitant chemoradiotherapy (CCRT) in treatment of locally advanced rectal carcinoma. We aimed at evaluating the potential impact of metformin on pathologic complete response (pCR) of rectal cancer cells to CCRT indiabetic patients; (2) Methods: A total of 50 diabetic patients with locally advanced rectal carcinomawere treated with neoadjuvant CCRT followed by surgery from June 2018 to June 2020. Patients were divided into metformin group (n = 25) and non metformin group (n = 25). Tumor response was compared between the two groups. Tumor response was also compared in relation to multiple predictive factors; (3) Results: The rates of pCR was significantly higher in metformin group (p = 0.025). The rates of pCR was also significantly higher in patients who had BMI <30 kg/m² (p = 0.021), pre treatment blood glucose level <200mg/dL(p = 0.005), and interval of radiotherapy to surgey≤8 weeks (p = 0.001); (4) Conclusions: Metformin use is associated with a significant increase in pathological complete response rates to concomitant chemoradiotherapy in diabetic patients with locally advanced rectal cancer.