Abstract
Cancer is the second cause of death. Association of diabetes as a growing and costly disease with cancer is a major health concern. Meanwhile, preexisting diabetes is associated with an increased risk of all-cause and cancer-specific mortalities. Presence of diabetes related comorbidities, poorer response to cancer treatment, and excess mortality related to diabetes are among the most important explanations. Although diabetes appear to be a risk factor for cancer and is associated with the mortality risk in cancer patients, several factors such as diabetes duration, multiple drug therapy, and the presence of diabetes comorbidities make the assessment of the effect of diabetes treatment on cancer risk and mortality difficult. Metformin is the drug of choice for the treatment of type 2 diabetes. The available evidence from basic science, clinical, and population-based research supports the anticancer effect of metformin. However, randomized controlled clinical trials do not provide enough evidence for a strong protective effect of metformin on cancer incidence or mortality. One of the most important limitations of these trials is the short duration of the followup. Further long-term randomized controlled clinical trials specifically designed to determine metformin effect on cancer risk are needed to provide the best answer to this challenge.
Highlights
An increase for site-specific cancer incidence has been described in many systematic reviews and metaanalyses
In a meta-analysis of 35 cohort studies, diabetes was associated with an increased risk of pancreatic cancer (SRR 1.94, 95% CI: 1.66–2.27)
Site-specific cancer mortality for colorectal cancer was evaluated in a systematic review and a meta-analysis of cohort studies by Jiang et al They reported that diabetes was associated with a 20% increase in the incidence of colorectal cancer that was independent of sex, body mass index, family history of colorectal cancer, smoking, geographic location, and physical activity [4]
Summary
The prevalence of diabetes in newly diagnosed cancer patients is reported to be from 8% to 18% [1]. A recent meta-analysis, of 29 cohorts and 16 case-control studies, examined the association between type 2 diabetes and risk of prostate cancer and showed a significant inverse association (RR 0.86, 95% CI: 0.80–0.92) [13]. Site-specific cancer mortality for colorectal cancer was evaluated in a systematic review and a meta-analysis of cohort studies by Jiang et al They reported that diabetes was associated with a 20% increase in the incidence of colorectal cancer that was independent of sex, body mass index, family history of colorectal cancer, smoking, geographic location, and physical activity [4]. Breast cancer outcomes in people with preexisting diabetes were reported in a systematic review and a metaanalysis by Peairs et al In this study preexisting diabetes was associated with 49% increase in all-cause mortality in patients with breast cancer.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
