Metformin use and improved response to therapy in rectal cancer
نویسندگان
چکیده
Locally advanced rectal cancer is commonly treated with chemoradiation prior to total mesorectal excision (TME). Studies suggest that metformin may be an effective chemopreventive agent in this disease as well as a possible adjunct to current therapy. In this study, we examined the effect of metformin use on pathologic complete response (pCR) rates and outcomes in rectal cancer. The charts of 482 patients with locally advanced rectal adenocarcinoma treated from 1996 to 2009 with chemoradiation and TME were reviewed. Median radiation dose was 50.4 Gy (range 19.8-63). Nearly, all patients were treated with concurrent 5-fluorouracil-based chemotherapy (98%) followed by adjuvant chemotherapy (81.3%). Patients were categorized as nondiabetic (422), diabetic not taking metformin (40), or diabetic taking metformin (20). No significant differences between groups were found in clinical tumor classification, nodal classification, tumor distance from the anal verge or circumferential extent, pretreatment carcinoembryonic antigen level, or pathologic differentiation. pCR rates were 16.6% for nondiabetics, 7.5% for diabetics not using metformin, and 35% for diabetics taking metformin, with metformin users having significantly higher pCR rates than either nondiabetics (P = 0.03) or diabetics not using metformin (P = 0.007). Metformin use was significantly associated with pCR rate on univariate (P = 0.05) and multivariate (P = 0.01) analyses. Furthermore, patients taking metformin had significantly increased disease-free (P = 0.013) and overall survival (P = 0.008) compared with other diabetic patients. Metformin use is associated with significantly higher pCR rates as well as improved survival. These promising data warrant further prospective study.
منابع مشابه
Evaluation of incidence of intestinal complications during radiation therapy in two supine and prone positions in patients with rectal cancer
Introduction: Radiation therapy is one of the main treatments for rectal cancer. In three-dimensional conformal radiotherapy, exposure of healthy tissue around the tumor is unavoidable. The small intestine is the most important organ at risk of rectal cancer radiotherapy. Intestinal complications are a major factor limiting the dose radiotherapy for rectal cancer. The most com...
متن کاملRectal cancer: a review
Rectal cancer is the second most common cancer in large intestine. The prevalence and the number of young patients diagnosed with rectal cancer have made it as one of the major health problems in the world. With regard to the improved access to and use of modern screening tools, a number of new cases are diagnosed each year. Considering the location of the rectum and its adjacent organs, ma...
متن کاملAssociation between the synonymous variant organic cation transporter 3 (OCT3)-1233G>A and the glycemic response following metformin therapy in patients with type 2 diabetes
Objective(s): Organic cation transporter 3 (OCT3) as a high-capacity transporter contribute to the metabolism of metformin. The present study was conducted to determine the genotype frequencies of the variant OCT3-1233G>A (rs2292334) in patients with newly diagnosed type 2 diabetes (T2D) and its relationship with response to metformin. Materials and Methods: This study included 150 patients wit...
متن کاملNew drug in neoadjuvant chemoradiation for rectal cancer
Background: In recent years, neoadjuvant chemoradiation and subsequent surgical resection with total mesorectal excision has been shown to increase local control with decreased toxicity. Neoadjuvant chemoradiotherapy is the standard treatment for locally advanced rectal cancer. In this study we evaluated the efficacy a cox-2 inhibitor on pathologic response, sphincter preservation and acute tox...
متن کاملAssociation between Metformin Use and Survival in Nonmetastatic Rectal Cancer Treated with a Curative Resection: A Nationwide Population Study
PURPOSE Metformin is associated with an anticancer effect. However, the effects of metformin in rectal cancer are controversial. This study investigated the impact of metformin on the survival of patients with diabetes mellitus and nonmetastatic rectal cancer who underwent curative surgery. MATERIALS AND METHODS The database was provided by the Korea Center Cancer Registry and National Health...
متن کامل