Tumor Necrosis Factor α administered to advanced cancer patients influences either directly or indirectly the endocrine glands and their hormonal secretion. In turn they modulate the biological activity of TNF α. Extensive evidence suggests that TNF α regulates the secretion of T3, T4, cortisol and melatonin. There exists scarce data concerning the effect of TNF α on prolactin levels (PRL) in human beings. The aim of this study was to determine whether TNF α treatment of non-operable cancer patients influenced PRL secretion. The study group comprised 15 patients suffering from colon cancer, who could only receive palliative treatment. Patients were treated with TNF α at a dose of 150 ug/day i.v. for 5 consecutive days (one cycle). Blood was collected several times a day before and following TNF α administration, PRL was measured by means of the RIA method. Results were reported as mean +SE. Single cosine analysis was used to estimate the circadian rhythm. In conclusion, TNF α demonstrated a stimulating effect on PRL secretion. It can probably act by direct activation of pituitary cell PRL receptors or indirectly by the modulation of other cytokines and hormonal secretion, which in turn stimulate PRL release.

Keywords: advanced neoplasms, prolactin, recombinant Tumor Necrosis Factor alpha therapy