Ectopic prolactin production by lung cancer cells as an indicator of aggressive nature of tumors.

Abstract

e20021 Background: Cancer cells use many unexpected molecular mechanisms to ensure their malignancy, and a comprehensive understanding of cancer cannot be achieved without a global consideration of all oncogenic events. Ectopic activation of tissue-specific hormones accompanies malignant transformation in many cancers. The aim of the study was to determine prolactin (PRL) levels in the blood, tumor and surrounding lung tissues in lung cancer patients of both sexes. Methods: Levels of PRL were measured in the blood and 10% homogenates of the tumor, perifocal tissues and intact lung tissues by radioimmune method using Immunotech kits (Czech Republic). The study included 33 men and 22 women with central and peripheral lung adenocarcinomas (T2-3N0-1M0), mean age 62±3.4 years, all women were menopausal. The comparison group included non-cancer patients (13 men and 12 women) operated on for chronic inflammatory lung diseases. Results: PRL levels in peripheral blood in 74% of men were increased by 3.7 times, and in 85% of women by 5.7 times. Peripheral cancer in men and women had no significant differences in prolactin levels; the hormone distribution was similar in the tumor, perifocal and intact tissues and was on average 1.5 times higher than in lung tissues in patients with inflammatory processes. Women with central cancer were characterized by higher tumor levels of PRL compared to men. In general, both in men and women, PRL levels in perifocal tissues and in intact lung tissue distant from the tumor focus were similar to tumor levels, which could indicate a general change in the organ metabolism, and not a local hormone synthesis by tumor tissues. Conclusions: The detected increase in the PRL content in lung tissues and in the blood may indicate the dysfunction of central regulatory mechanisms and a change in lung metabolism, being one of the links in the causal mechanisms of tumor development.