Insulin resistance, its consequences for the clinical course of the disease, and possibilities of correction in endometrial cancer

To study the frequency of insulin resistance (IR) in endometrial cancer patients, its relation to the clinical course of the disease and DNA damage, and to evaluate possible approaches to the pharmacological correction of IR in the patients studied.

The signs of insulin resistance syndrome and its association with the clinical and pathological features of the disease and DNA damage in somatic cells (micronucleus frequency in peripheral blood lymphocytes) and endometrial normal and tumor tissue (alkaline unwinding) were determined in 99 endometrial cancer patients.

The frequency of insulin resistance syndrome counted on the basis of fasting plasma glucose and insulin concentrations according to Duncan et al. is equal to 0.35 (95% CI 0.24–0.46), or 35%, in endometrial cancer patients who do not have a history of diabetes mellitus. Patients with well- or moderately differentiated endometrial adenocarcinomas (mostly type I) had statistically significantly higher basal and stimulated plasma insulin and C-peptide concentrations than patients with poorly differentiated endometrial adenocarcinomas or rarely encountered tumors of the endometrium (primarily type II). Interestingly, the level of fasting insulinemia positively correlates with disease stage and with local and regional tumor dissemination only in the group of patients with well- or moderately differentiated endometrial adenocarcinomas. On the other hand, hyperinsulinemia and other hormonal-metabolic disturbances typical of insulin resistance syndrome do not increase the probability of DNA damage of somatic cells (according to the data of micronucleus test). In addition, no association between hormonal-metabolic disturbances and the degree of DNA unwinding in tumor and visually unchanged endometrium was found.

Thus, insulin resistance/hyperinsulinemia is associated with a more aggressive course of the disease in certain groups of the patients but—in contrast to excessive estrogenic stimulation—does not result in increased genotoxic damage in tumor and normal tissues. The data obtained once more confirm the need for treatment and prevention measures aimed at correcting hormonal-metabolic disturbances in endometrial cancer patients and groups at risk of this disease. Such an approach might include use of antidiabetic biguanides, thiazolidinediones (glitazones), and statins.