For colorectal cancer patients with type II diabetes, could metformin improve the survival rate? A meta-analysis

Clin Res Hepatol Gastroenterol. 2020 Feb;44(1):73-81. doi: 10.1016/j.clinre.2019.06.009. Epub 2019 Jul 9.

Abstract

Objective: Current research is controversial about whether metformin can improve the survival rate of patients with colon cancer. Therefore, we conducted a meta-analysis to identify the association between metformin and the survival rate of colorectal cancer (CRC) patients with type II diabetes.

Methods: We conducted a search in databases including Pubmed, EMBASE and Cochrane Library. All articles were published in the last decade, and the quality of each study was evaluated by the Newcastle-Ottawa Scale. Odds ratios (ORs) and its corresponding 95% confidence intervals (CIs) for each study were calculated and summary relative risk estimates with corresponding 95% CIs were generated using the random-effects model. Heterogeneity and publication bias were assessed.

Results: Ten articles were included in this meta-analysis. The included articles were all cohort studies. In a pooled analysis of all studies, metformin using was associated with increased overall survival (OS) rate (OR, 0.54; 95% CI, 0.47 to 0.63) and cancer-specific survival (CS) rate (OR 0.59; 95% CI 0.43 to 0.82) of CRC patients with diabetes. We found that the effect of metformin is associated with geographical region through subgroup meta-analysis.

Conclusions: Metformin using was associated with an increased OS rate and CS rate of colorectal cancer.

Keywords: Colorectal cancer; Diabetes; Metformin; Overall survival.

Publication types

  • Meta-Analysis

MeSH terms

  • Colorectal Neoplasms / complications
  • Colorectal Neoplasms / mortality*
  • Diabetes Complications / mortality*
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Humans
  • Hypoglycemic Agents / therapeutic use*
  • Metformin / therapeutic use*
  • Survival Rate

Substances

  • Hypoglycemic Agents
  • Metformin