Neuroendocrine effects of subcutaneous interleukin-2 injection in cancer patients

Intravenous interleukin-2 (IL-2) administration has been shown to influence several hormonal secretions. The present study was carried out to investigate the endocrine effects of subcutaneous therapy with IL-2. Six patients with advanced renal cancer were studied. They were treated subcutaneously with IL-2 according to the schedule proposed by Atzpodien et al. Venous blood samples were collected at O-time and 1, 8 and 12 hours after the first IL-2 pulse of 9 X 10(6) IU/m2 at 8.00 a.m.; on a separate occasion, samples were collected during a saline infusion only. In each blood sample, serum levels of cortisol, beta-endorphin, GH, PRL, FSH, LH, TSH and the pineal hormone melatonin were measured by RIA. Both cortisol and beta-endorphin significantly increased after IL-2 injection. GH rose but not to a significant extent. PRL, FSH, LH and TSH did not change after IL-2. Finally, melatonin levels markedly decreased after IL-2 injection in the only 2 patients with elevated concentrations of this hormone before the start of immunotherapy. These results suggest that the endocrine effects of subcutaneous IL-2 therapy are similar to those previously described with intravenous administration.