Impact of diabetes mellitus on clinical outcomes of pancreatic cancer after surgical resection: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE: Diabetes mellitus (DM) is a risk factor for pancreatic cancer but its impact on postoperative outcomes and long-term survival after cancer resection remains controversial. A meta-analysis of published studies was conducted to address this issue. METHODS: An extensive electronic search of four databases was performed for relevant articles. Data were processed for meta-analysis using Review Manager version 5.1. RESULTS: Seventeen observational studies involving 5407 patients were subjected to the analysis. Overall morbidity or any type of complications and mortality were comparable between diabetic and non-diabetic subjects. Overall DM has a significant negative impact on survival (risk ratio [RR], 1.24, 95% confidence interval [CI], 1.05–1.45; P = 0.01). Stratification by the type of DM revealed that new-onset DM (<2 years duration, RR, 1.54, 95% CI, 1.24–1.91; P <0.001) but not long-standing DM (≥2 years duration, RR, 1.74, 95% CI, 0.86–3.52; P = 0.12) was associated with reduced survival. CONCLUSIONS: Diabetes mellitus does not affect perioperative outcomes in patients undergoing surgery for pancreatic cancer. However, new-onset DM confers a negative impact on survival of pancreatic cancer in patients undergoing surgical resection.