Cancer incidence and mortality in patients with insulin-treated diabetes: a UK cohort study

Abstract

Raised risks of several cancers have been found in patients with type II diabetes, but there are few data on cancer risk in type I diabetes. We conducted a cohort study of 28 900 UK patients with insulin-treated diabetes followed for 520 517 person-years, and compared their cancer incidence and mortality with national expectations. To analyse by diabetes type, we examined risks separately in 23 834 patients diagnosed with diabetes under the age of 30 years, who will almost all have had type I diabetes, and 5066 patients diagnosed at ages 30 -49 years, who probably mainly had type II. Relative risks of cancer overall were close to unity, but ovarian cancer risk was highly significantly raised in patients with diabetes diagnosed under age 30 years (standardised incidence ratio (SIR) ¼ 2.14; 95% confidence interval (CI) 1.22 -3.48; standardised mortality ratio (SMR) ¼ 2.90; 95% CI 1.45-5.19), with greatest risks for those with diabetes diagnosed at ages 10 -19 years. Risks of cancer at other major sites were not substantially raised for type I patients. The excesses of obesity-and alcohol-related cancers in type II diabetes may be due to confounding rather than diabetes per se.

Diabetes mellitus and risk of endometrial cancer: a meta-analysis

“…Of these 25 studies, five were cohort studies that used incidence and/or mortality rate ratios as the measure of RR [9,21,[24][25][26] (Table 1), 13 were case-control studies [10-20, 22, 23] (Table 2) and seven were cohort studies that used standardised incidence and/or mortality ratio as the measure of risk [34][35][36][37][38][39][40] (Table 3). Twelve studies were conducted in the USA, ten in Europe, one in South America and one in Asia.…”

“…These 16 studies had 96,003 participants. The four cohort studies [34,[36][37][38] that reported standardised incidence ratios were analysed separately. For the meta-analysis of diabetes and endometrial cancer mortality, we included the two cohort studies that reported mortality rate ratio [21,26].…”

“…These two studies enrolled a total of 896 participants. The four cohort studies [34,[36][37][38] that reported standardised incidence ratios and the three cohort studies [34,39,40] that reported standardised mortality ratios were analysed separately.…”

“…Four studies reported on type 1 diabetes and endometrial cancer, one case-control study [11], two studies providing standardised incidence ratio [34,35] and one study Measure of relative risk is an odds ratio except for one (Maatela, 1994 [15]). …”

“…CIs were calculated from raw data reported in the article reporting on type 1 diabetes and endometrial cancer mortality providing a standardised mortality ratio [34].…”