The mTOR inhibitor everolimus in combination with carboplatin in metastatic breast cancer--a phase I trial.

AIM: Despite advances in the the first- and second-line treatment of metastatic breast cancer, there remains a large unmet need for additional treatment options. As preclinical studies have suggested that combining everolimus with carboplatin may produce higher activity than each drug by itself, we initiated a phase I study of this combination. PATIENTS AND METHODS: Patients with pre-treated metastatic breast cancer received weekly carboplatin at AUC2 and daily oral everolimus at different dose-levels (level I: 2.5 mg; II: 5 mg; III: 7.5 mg; IV: 10 mg). Three patients were assigned to dose-levels I to III, and six to dose-level IV. The primary end-point was to determine the maximum tolerated dose (MTD). RESULTS: Fifteen patients were recruited to the study. The median number of previous chemotherapies was four (range: 1-11). No dose-limiting toxicity occurred at levels I-III during the first cycle. Based on the pre-determined definition, the maximum planned dose-level IV was selected as the MTD. Patients received a median of four cycles of treatment (range 1-13). Most frequent grade 3 and 4 toxicities included leukopenia, thrombocytopenia and infection. Response rates were as follows: 21% partial response, 43% stable disease, and 36% progressive disease. CONCLUSION: Carboplatin and everolimus is a well-tolerated combination for heavily pre-treated metastatic breast cancer. Everolimus (10 mg/d) and carboplatin (AUC2 weekly) were defined as the MTD. This dose is currently being employed in an ongoing phase II trial.

5FU continuous infusion in heavily pretreated advanced breast cancer patients.

BACKGROUND: Despite advances in the first- and secondline treatment of advanced breast cancer, optimal therapy thereafter remains controversial. Treatment of heavily pretreated patients is not standardized, often of low efficacy, and limited by comorbidity. In these patients, an effective treatment with low toxicity is needed. PATIENTS AND METHODS: We retrospectively analyzed all metastatic breast cancer patients treated with 5-fluorouracil as continuous infusion (CI-5FU) with daily doses of 150-300 mg/m(2). RESULTS: 43 patients were treated with CI-5FU until disease progression. The median number of metastatic sites was 3. Most patients were heavily pretreated with a median of 3 palliative chemotherapies (range 1-11). 42 patients were evaluable for objective response; among them 5 (12%) showed a partial response (PR) and 6 (15%) showed stable disease (SD) lasting at least 6 months, leading to a clinical benefit (CB) rate (complete response + PR + SD ≥ 6 months) of 27%. The median time to progression of patients with CB was 10 months (range 3-22). Overall survival of all patients from the start of CI-5FU was 8 months (range 1-75) and from the time of first metastases 42 months (range 9-281). Toxicity was low even in patients with hepatic insufficiency. CONCLUSION: CI-5FU showed a positive efficacy/toxicity ratio. Taking into account the high number of previous treatments, it results in a remarkable CB rate of 27%.

Primary tumor excision in stage IV breast cancer at diagnosis without influence on survival: a retrospective analysis and review of the literature.

BACKGROUND: Patients with synchronous metastastic breast cancer and intact primary tumor traditionally undergo systemic treatment. Surgical intervention at the primary site is typically reserved for palliation and often replaceable by radiation. Nevertheless, local surgery in metastatic breast cancer has become an issue of great controversy since retrospective studies published during the recent years suggested a slight benefit from an operative procedure. We evaluated the effect of surgery on long-term survival and progression-free survival in synchronous stage IV breast cancer. METHODS: We retrospectively reviewed the records of all breast cancer patients treated at our institution between 1986 and 2007. Information recorded for each patient included age, tumor characteristics, metastasis characteristics, therapy, progression-free survival, and overall survival. Survival data were compared between surgical and nonsurgical patients. RESULTS: 61 patients with synchronous metastastic breast cancer and intact primary tumor were analyzed. 26 patients (43%) received no primary site surgery and 35 (57%) patients had surgery. Overall survival and progression-free survival determined via the Kaplan-Meier method showed no significant difference between the surgery and the non-surgery group. CONCLUSION: In patients with metastatic breast cancer, the operation of the primary tumor did not influence overall survival or progression-free survival.

The mTOR inhibitor RAD001 sensitizes tumor cells to the cytotoxic effect of carboplatin in breast cancer in vitro.

AIM: The phosphatidylinositol 3-kinase (PI3K)/protein kinase B(AKT)/mammalian target of rapamycin (mTOR) signaling pathway is aberrantly activated in many types of cancer, including breast cancer. It is recognized that breast cancer cells develop resistance to a variety of standard therapies through the activation of this pathway. We hypothesized that targeting this signaling by the mTOR inhibitor RAD001 may potentiate the cytotoxicity of a conventional chemotherapeutic drug, carboplatin, and enhance the treatment efficacy for breast cancer. MATERIALS AND METHODS: Cell proliferation was measured with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay; cell apoptosis with enzyme-linked immunosorbent assay (ELISA). Flow cytometry was used for the analysis of cell cycle distribution and mitochondrial membrane function. Gene expression at the protein level was determined by Western blot. RESULTS: MTOR inhibitor RAD001 enhanced the sensitivity of breast cancer cells to carboplatin. RAD001 in combination with carboplatin resulted in synergistic inhibition of cell proliferation and caspase-independent apoptosis in these cells. Moreover, in MCF-7 and BT-474 cells, synergistic effects of this combination on G2/M cell cycle arrest and regulation of different molecules responsible for cell cycle transition and apoptosis were observed. The p53 pathway was involved in the synergism of RAD001 and carboplatin on breast cancer cell proliferation and apoptosis, since the synergistic effect was demonstrated in all tested breast cancer cell lines with wild-type p53 and the use of p53 inhibitor partially antagonized the effect of RAD001 and carboplatin on p53 and p21 expression, as well as their inhibitory effect on cell proliferation. However, a synergistic effect of the combination of the two drugs on cell proliferation was observed in two p53-mutated cell lines with high AKT expression, suggesting that an alternative mechanism underlying the observed synergism exists. CONCLUSION: Our results suggest that the combination of RAD001 and carboplatin is a promising treatment approach for breast cancer. On the basis of these results, we have initiated a phase I/II clinical trial with the combination of carboplatin and RAD001 in patients with metastatic breast cancer.