Long-term All-Cause Mortality in Cancer Patients With Preexisting Diabetes Mellitus

Abstract

Context Diabetes mellitus appears to be a risk factor for some cancers, but the effect of preexisting diabetes on all-cause mortality in newly diagnosed cancer patients is less clear. Objective To perform a systematic review and meta-analysis comparing overall survival in cancer patients with and without preexisting diabetes. Data Sources We searched MEDLINE and EMBASE through May 15, 2008, including references of qualifying articles. Study Selection English-language, original investigations in humans with at least 3 months of follow-up were included. Titles, abstracts, and articles were reviewed by at least 2 independent readers. Of 7858 titles identified in our original search, 48 articles met our criteria. Data Extraction One reviewer performed a full abstraction and other reviewers verified accuracy. We contacted authors and obtained additional information for 3 articles with insufficient reported data. Results Studies reporting cumulative survival rates were summarized qualitatively. Studies reporting Cox proportional hazard ratios (HRs) or Poisson relative risks were combined in a meta-analysis. A random-effects model meta-analysis of 23 articles showed that diabetes was associated with an increased mortality HR of 1.41 (95% confidence interval [CI], 1.28-1.55) compared with normoglycemic individuals across all cancer types. Subgroup analyses by type of cancer showed increased risk for cancers of the endometrium (HR, 1.76; 95% CI, 1.34-2.31), breast (HR, 1.61; 95% CI, 1.46-1.78), and colorectum (HR, 1.32; 95% CI, 1.24-1.41). Conclusions Patients diagnosed with cancer who have preexisting diabetes are at increased risk for long-term, all-cause mortality compared with those without diabetes.

Impact of cancer on adherence to glucose-lowering drug treatment in individuals with diabetes

“…Another study showed that individuals with diabetes and recent HbA 1c values >9.0% (75 mmol/mol; OR 1.5; 95% CI 1.3, 1.7) had higher mortality than those with recent 'normal' HbA 1c values between 6.5% (48 mmol/mol) and 9% (75 mmol/mol) [18]. Thus, the drop in MPR observed among patients with cancer in our study might have negatively influenced survival via the aforementioned mechanisms and may (partly) explain the established association between diabetes, cancer and survival [1][2][3].…”

“…Cancer patients with diabetes have a significantly higher overall mortality risk than those without diabetes [1][2][3]. To understand the association between diabetes and cancer, the American Diabetes Association and American Cancer Society reviewed the state of science regarding this in 2010 [4].…”

Does diabetes therapy influence the risk of cancer?

“…One point has become abundantly clear, and this is that cancer must now be numbered among the complications of diabetes. Furthermore, and as with ischaemic heart disease, cancer is associated with a higher mortality in those with diabetes than in those without [53]. Cancer risk and prevention may become increasingly important considerations in diabetes therapy, and the implications of the studies reported here are likely to be very far-reaching.…”

Trajectory of body shape in early and middle life and all cause and cause specific mortality: results from two prospective US cohort studies

“…Increasing evidence also relates diabetes to a higher risk of cancer, including cancers of the pancreas, endometrium, liver, colorectum, and breast, possibly by mechanisms related to hyperinsulinema, hyperglycemia, and chronic inflammation 46. Furthermore, some studies found that diabetes may increase mortality in patients with cancer 47. Patients with cancer and pre-existing diabetes had a higher mortality than their non-diabetic counterparts, even after adjustment for BMI 48…”