Increased risk of cancer in patients with type 2 diabetes mellitus: A retrospective cohort study in China

Abstract

BackgroundPrevious studies indicated that type 2 diabetes mellitus (T2DM) might be associated with the risk of cancer. The aim of this study was to investigate the association between T2DM and the risk of developing common cancers in a Chinese population.MethodsA population-based retrospective cohort study was carried out in the Nan-Hu district of Jiaxing city, Zhejiang province, China. The incidence of cancer cases among type 2 diabetic patients were identified through record-linkage of the Diabetic Surveillance and Registry Database with the Cancer Database from January 2002 to June 2008. The standardized incidence ratio (SIR) and 95% confidence interval (CI) were estimated for the risk of cancer among the patients with type 2 diabetes.ResultsThe overall incidence of cancer was 1083.6 per 105 subjects in male T2DM patients and 870.2 per 105 in females. Increased risk of developing cancer was found in both male and female T2DM patients with an SIR of 1.331 (95% CI = 1.143-1.518) and 1.737 (1.478-1.997), respectively. As for cancer subtypes, both male and female T2DM patients had a significantly increased risk of pancreatic cancer with the SIRs of 2.973 (1.73-4.21) and 2.687 (1.445-3.928), respectively. Elevated risk of liver and kidney cancers was only found in male T2DM patients with SIRs of 1.538 (1.005-2.072) and 4.091 (1.418-6.764), respectively. Increased risks of developing breast cancer [2.209 (1.487-2.93)] and leukemia SIR: [4.167 (1.584- 6.749) ] were found in female patients.ConclusionsThese findings indicated that patients with T2DM have an increased risk of developing cancer. Additional cancer screening should be employed in the management of patients with T2DM.

Metformin use and its effect on gastric cancer in patients with type 2 diabetes: A systematic review of observational studies

“…Several epidemiological studies have observed an increased risk of cancer (22)(23)(24)(25)(26), including stomach cancer (27)(28)(29), colon, breast, endometrial, liver, pancreatic and bladder cancer (30,31), and prostate cancer (32), in DM patients; however, the precise underlying mechanisms have not been elucidated. Factors such as insulin resistance, secondary Table II.…”

Diabetes Mellitus Increases the Risk of Bladder Cancer: An Updated Meta-analysis

“…However there were still some limitations in this published meta-analysis: (1) The studies and samples were insufficient for which did not contained many new studies with a large number of samples which reported in recent years (Manami et al, 2006;Rousseau, 2006;Susanna et al, 2008;Li et al, 2011;MacKenzie et al, 2011;Tseng, 2011;Attner et al, 2012;Zhang et al, 2012;Newton et al, 2013;Prizment et al, 2013). So the population included in it was too small to reveal the actual relationship between DM and the bladder cancer risk.…”

“…To date, many large sample epidemiological studies have investigated the important role of DM in bladder cancer development. The results were inconsistent or even contradictory, some of studies did not support an association of DM with overall bladder cancer incidence (Rousseau et al, 2006;Larssona et al, 2008;Zhang et al, 2012). So after removing the three unqualified literature (Kessler, 1970;Kantor et al, 1984;Verlato et al, 2003), adding the new studies which were not included in above meta-analysis, we performed a meta-analysis of 23 published studies covering 643,683 cases and 4,819,656 controls to get a more precise evaluation of the association between DM and the risk of bladder cancer.…”

“…The results of the data extraction were summarized in a structured table to explore the variation. There were five cohort studies without original data of control group (used expected events and SIR to estimated the relative risk), we hypothesized that the population of the control was same as the case (Adami et al, 1991;Wideroff et al, 1997;Zendehdel et al, 2003;Swerdlow et al, 2005;Zhang et al, 2012).…”

“…Twenty three relevant studies were retrieved about incidence, including eight case-control studies (O'Mara et al, 1985;Risch et al, 1988;Vecchia et al, 1994;Kravchick et al, 2001;Ng et al, 2003;Rousseau et al, 2006;MacKenzie et al, 2011;Attner et al, 2012), fifteen cohort studies (Ragozzino et al, 1982;Adami et al, 1991;Wideroff et al, 1997;Tripathi et al, 2002;Zendehdel et al, 2003;Coughlin et al, 2004;Swerdlow et al, 2005;Jee et al, 2005;Inoue et al, 2006;Larssona et al, 2008;Li et al, 2011;Tseng et al, 2011;Zhang et al, 2012;Newton et al, 2012;Prizment., 2013), comprising a total of 643,683 patients with DM and 4,819,656 patients without DM. The characteristics of selected studies are summarized in Table 1.…”