Abstract 502: The association of metformin dose and cancer survival in older adults with advanced cancer: SEER-Medicare analysis

Abstract

Abstract Cancer and type 2 diabetes (T2DM) are common diseases that have serious health consequences. T2DM is known to increase the risk for the development of many of the most common cancers. Metformin, one of the most commonly used drugs to treat T2DM, is increasingly being used for its anticancer effects; however, the literature is limited on the effect of metformin dose on OS in patients with advanced cancer. We examined the relationship between metformin dose and OS in persons with both T2DM and stage IV lung, breast, colorectal, prostate, or pancreas cancers. Methods: We used a retrospective study design with cox proportional hazards regression analysis of the 2007-2016 of the Surveillance Epidemiology and End Results-Medicare dataset. Results: A total of 7,725 patients with T2DM and a least one targeted cancer was included in the analysis. Of those patients, 38.5% had been prescribed metformin. Patients who used metformin had significantly better OS in both unadjusted (Unadjusted HR, 0.73; 95% CI, 0.69-0.76; p < 0.001) and adjusted models (adjusted HR, 0.77; 95% CI, 0.73-0.81; p < 0.001). The OS between patients who took metformin with average daily dose ≥ 1000mg or < 1000mg were not statistically significant (aHR, 1.00; 95% CI, 0.93-1.08; p=0.90). Conclusions: Metformin use, regardless of dose, increases OS in older adults with advanced cancer. Additionally, OS was not significantly different across race or ethnicity. Citation Format: Lisa Scarton, Ara Jo, Zhigang Xie, LaToya J. O’Neal, Juan M. Pena, Thomas J. George, Jiang Bian. The association of metformin dose and cancer survival in older adults with advanced cancer: SEER-Medicare analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 502.