Insulin use is not significantly predictive for prostate cancer mortality in diabetic patients: a 12‐year follow‐up study

Abstract

Study Type – Prognosis (inception cohort) Level of Evidence 2a What's known on the subject? and What does the study add? Even though a lower risk of prostate cancer has been reported in patients with diabetes, they may have a higher risk of cancer development involving the liver, pancreas, endometrium, colorectum, breast and bladder. Insulin may have mitogenic properties besides its metabolic function. However, whether exogenous insulin use for glycaemic control in diabetic patients could increase the risk of prostate cancer has rarely been studied. This is the first prospective follow‐up study for up to 12 years to show that exogenous insulin use for glycaemic control in the diabetic patients is not significantly predictive for prostate cancer mortality. OBJECTIVE To evaluate whether insulin use in diabetic patients could be predictive for prostate cancer mortality. PATIENTS AND METHODS A total of 39 135 diabetic men aged ≥40 years from a nationally representative cohort were followed prospectively from 1995 to 2006 for prostate cancer mortality. Cox proportional hazards models were used to estimate the hazard ratios for the following independent variables: age, diabetes type, diabetes duration, body mass index, smoking, insulin use and area of residence. The models were created for patients aged ≥40 years and ≥65 years, separately; and before and after excluding patients with a duration between onset of diabetes and prostate cancer mortality <5 years. RESULTS A total of 105 diabetic men died of prostate cancer during follow‐up. Age was the only significant risk factor. Insulin use was associated with an insignificantly higher risk of prostate cancer mortality ranging from 24% to 49%. When stratified by the duration of insulin use <5 and ≥5 years, a lack of significant association was also observed. CONCLUSIONS Insulin use in diabetic patients does not significantly predict the mortality from prostate cancer. Further confirmation in other ethnicities is needed.

Human Insulin Does Not Increase Prostate Cancer Risk in Taiwanese

“…In a previous 12-year prospective follow-up of a large cohort of patients with diabetes, use of human insulin at baseline (from 1995 to 1998, before the marketing date of insulin analogues in Taiwan) is not significantly associated with the risk of prostate cancer mortality. 19 Taken together with the findings of the present study, it is almost safe to conclude that use of human insulin might not affect the risk of prostate cancer in terms of either mortality or incidence.…”

Growth Modulation of Diabetic Factors and Antidiabetic Drugs on Prostate Cancer Cell Lines

“…Insulin did not increase the proliferation of AR-expressing PCa cell lines. This may explain the lack of clinical effectiveness of insulin use on the risk and mortality of PCa (34,35).…”

Latest Evidence on the Impact of Smoking, Sports, and Sexual Activity as Modifiable Lifestyle Risk Factors for Prostate Cancer Incidence, Recurrence, and Progression: A Systematic Review of the Literature by the European Association of Urology Section of Oncological Urology (ESOU)

“…Rohrmann et al [12] analyzed US cohorts started in 1963 and 1975 and did not find a significant impact on CSM in the entire cohorts (HR 0.93; 95% CI: 0.67-1. 29 Four cohort studies were not able to confirm an independent impact of smoking on outcome [46][47][48][49]. Batty et al [46] did not find an association between smoking and CSM (current vs never smokers: HR 1.14; 95% CI: 0.91-1.44).…”