The impact of type 2 diabetes mellitus on mortality in hospitalized female cancer patients in Taiwan

Introduction: The goal of this study was to determine the relationships among type 2 diabetes mellitus (DM), specific cancer histological types and mortality in hospitalized women. Methods: Patients over 19 years of age were included if the indication for hospital admission was a diagnosis of type 2 DM or a malignancy. In total, 67660 female patients with a mean age 62.76±14.48 years were enrolled. These patients were categorized into the following three groups: patients with cancer but without type 2 DM (group A); patients with cancer and type 2 DM (group B) and patients with type 2 DM but without cancer (group C). Attributable fractions (AF) were calculated as ([hazard ratio-1]/hazard ratio)×100 to evaluate the impact of type 2 DM on mortality for specific cancers. Results: Of the study participants, 37204 (55%) were diagnosed with type 2 DM. The patients were categorized as follows: group A, 30456 patients; group B, 5992 patients and group C, 31212 patients. Group B patients had high frequencies of pancreatic, liver and renal cancers and low frequencies of thyroid, breast and ovarian cancers. Of the 36448 cancer patients, 2906 (8%) died. The mortality rate in group B (10 %) was significantly higher than that in groups A and C. Type 2 DM was associated with increased mortality and AF for thyroid, nasopharyngeal, urinary tract, ovarian, breast and cervical cancers (hazard ratio over 1.50). Conclusion: The incidence of type 2 DM in patients with different histological types of cancer varied widely, ranging from 8-34%. Among the cancer patients, type 2 DM had a significantly greater impact on the mortality rates of patients with cancers associated with relatively low mortality.