(ChemotherapyAdvisor) – Metformin use was associated with improved outcome of patients with diabetes and pancreatic cancer, according to a study published in Clinical Cancer Research online March 31.
The retrospective study identified 302 patients with diabetes and pancreatic cancer treated at The University of Texas M.D. Anderson Cancer Center, Houston, TX. Medical record review and personal interviews were used to collect information on diabetes history, including treatment modalities and clinical outcome of pancreatic cancer.
No significant differences in demographic or major clinical characteristics were observed between the patients who had received metformin (n=117) and those who had not (n=185). At one year, the survival rate was 63.9% for those prescribed metformin vs. 46.3% in the non-metformin group. At two years, the survival rate was 30.1% for the metformin group and 15.4% for the non-metformin group (P=0.004).
Median overall survival was 15.2 months for the metformin group and 11.1 months for the non-metformin group (P=0.004). Patients who used metformin had a 32% lower risk of death; however, a significant association with longer survival was observed only in those with nonmetastatic disease.
The investigators suggested that metformin may be acting on insulin resistance observed in both diabetes and pancreatic cancer as well as on the AMPK/AKT/mTOR signaling pathway and recommended future research “prospectively evaluate metformin as a supplemental therapy in this population.”
Three additional preclinical studies, two published in Cancer Prevention Research and one in Cancer Discovery, also focused on the role of metformin in cancer. Metformin prevented liver tumorigenesis by inhibiting pathways driving hepatic lipogenesis in mice; prevented development of oral squamous cell carcinomas from carcinogen-induced premalignant lesions in mice; and accelerated growth of BRAFV600E-driven melanoma by upregulating VEGF-A in both cell lines and in mice.