Biological response modifiers of cancer-related neuroendocrine disorders: efficacy of the long-term dopaminergic agonist cabergoline in the treatment of breast cancer-induced hyperprolactinemia.

The evaluation of the biological status of cancer patients should not be limited only to investigation of immune reactivity, but should also include analysis of the endocrine condition, namely concerning those hormones which have appeared to be tumor growth factors, such as prolactin (PRL) for breast and prostate carcinomas. This statement is justified by the fact that the evidence of abnormally high serum concentrations of PRL has been proven to be associated with poor prognosis in breast and prostate cancer patients. Moreover, since hyperprolactinemia negatively influences the efficacy of anticancer therapies in breast cancer, it could be fundamental to achieve a normalization of PRL levels by long-acting dopaminergic agents, such as cabergoline. On this basis, a study was planned to evaluate the effect of cabergoline on PRL levels in hyperprolactinemic metastatic breast cancer subjects. The study included 20 hyperprolactinemic metastatic breast cancer subjects, who were randomized to receive no therapy or cabergoline at 0.5 mg/week orally for 4 consecutive weeks. Cabergoline therapy induced a normalization in all patients, whereas no spontaneous normalization of PRL levels occured in the control group. These results show that a weekly oral administration of the long-acting dopaminergic agent cabergoline is a well tolerated and effective treatment of metastatic breast cancer-related hyperprolactinemia. The possible prognostic impact of PRL normalization needs to be established by successive studies.

Immunotherapy with low-dose subcutaneous interleukin-2 plus beta-interferon as a second-line therapy for metastatic colorectal carcinoma.

AIMS AND BACKGROUND: Beta-interferon (beta-IFN) has been proven to influence some IL-2-induced immune effects. On the basis of these experimental data, we evaluated the immunobiologic effects of an association between very low-dose IL-2 and beta-IFN in advanced cancer patients. METHODS: The study was performed in 15 metastatic colon cancer patients, who progressed in response to a first-line chemotherapy with 5-FU plus folates. IL-2 was given subcutaneously at a daily dose of 3 million IU in the evening for 6 days/week for 4 weeks. beta-IFN was injected subcutaneously at a dose of 3 million U/day for 7 days before the first IL-2 injection, then thrice/week until the end of IL-2 administration. In nonprogressed patients, a second cycle was given after a 14-day rest period. RESULTS: No objective tumor regression was seen. Stable disease was obtained only in 2/15 patients; the other 13 progressed. Toxicity was low in all cases. Natural killer cell and T-activated lymphocyte mean number significantly increased during the immunotherapy. Lymphocyte and eosinophil mean number also increased, without, however, significant differences. IL-2-induced suppressive events, consisting of an increase in T-suppressor cell number, and soluble IL-2 receptor levels were not blocked by beta-IFN. CONCLUSIONS: The study showed that the concomitant administration of beta-IFN may determine an improvement in the immune performance in metastatic cancer patients treated with very low-dose IL-2, even though this biologic improvement does not seem to be associated to a control of tumor development. Further studies in patients with less advanced disease are needed to better define the impact of the immune improvement induced by low-dose IL-2 plus beta-IFN on the clinical course of the neoplastic disease.