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Epirubicin and vinorelbine are considered active drugs in metastatic breast cancer. The optimal duration of a chemotherapy regimen for metastatic breast cancer patients is still unknown. Nevertheless, epirubicin has a dose-limiting cardiotoxicity. Vinorelbine is also available as oral formulation. In a multicenter phase II study, we analyzed the feasibility and the efficacy of a maximum of six cycles of i.v. epirubicin plus vinorelbine, followed by oral vinorelbine. We enrolled 30 patients with metastatic breast cancer. Each patient received epirubicin (75 mg/m2 on day 1) and vinorelbine (25 mg/m2 on days 1–8), every 3 weeks, for three cycles or six cycles in case of objective response or stable disease. When a clinical benefit was obtained, patients received oral vinorelbine (60 mg/m2 on days 1–8 every 3 weeks for three cycles). The regimen demonstrated to be active and well tolerated in metastatic breast cancer, and 6–8 months represented the optimal treatment duration. Maintenance therapy with oral vinorelbine was feasible, effective, safe and well accepted by the patients.

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.

In view of its potential action as a growth factor, the evidence of abnormally high blood levels of prolactin (PRL) is associated with a poor prognosis in metastatic breast cancer. Moreover, metastatic breast cancer-related hyperprolactinemia has proven to counteract the efficacy of cancer chemotherapy. The negative influence of high blood levels of PRL on the efficacy of chemotherapy in metastatic breast cancer has been confirmed by previous preliminary studies, showing that the concomitant administration of the anti-prolactinemic dopaminergic agent bromocriptine may enhance the therapeutic effect of chemotherapy. However, the clinical use of bromocriptine is limited by its short duration and gastrointestinal toxicity. Therefore, new anti-prolactinemic drugs, characterized by less toxicity and a longer duration of activity, such as Cabergoline (CBG), could be more appropriated to control PRL secretion in breast cancer. On this basis, a study was planned to evaluate the efficacy and tolerability of a concomitant administration of CBG with weekly low-dose Taxotere (TXT) in pretreated metastatic breast cancer under chemotherapy. The study group comprised 70 metastatic breast cancer patients (females), pretreated with at least one previous chemotherapeutic line containing anthracyclines, who were randomized to be treated with TXT alone or TXT plus CBG. TXT 25 mg/m2 was given i.v. at weekly intervals for at least 9 consecutive cycles. CBG was given orally at 0.5 mg once per week. Abnormally high pre-treatment levels of PRL were seen in 24/70 (34%) patients, 11 of whom were treated with TXT plus CBG, whereas the other 13 received TXT alone. CBG induced a complete normalization of the PRL levels in all patients within the first two weeks of therapy, whereas no normalization of PRL occurred spontaneously in patients treated with chemotherapy alone. The objective tumor regression rate was significantly higher in patients concomitantly treated with CBG than in those who received chemotherapy alone (31/34 vs 13/36, p < 0.05), and this difference was particularly evident in patients with high PRL levels prior to therapy (6/11 vs 2/13). No CBG-related toxicity occurred. On the contrary, chemotherapy-induced asthenia was significantly lower in patients concomitantly treated with CBG (5/34 vs 11/36, p < 0.05). This study shows that the chemoneuroendocrine therapy of weekly low-dose TXT plus the anti-prolactinemic drug CBG is a new, effective and well-tolerated therapy for metastatic breast cancer. It may also be recommended in heavily pretreated patients or in those with poor clinical status.