Phase II study of liposomal doxorubicin, docetaxel and trastuzumab in combination with metformin as neoadjuvant therapy for HER2-positive breast cancer.

BACKGROUND: The aim of this study was to improve activity over single human epidermal growth factor receptor 2 (HER2)-blockade sequential neaodjuvant regimens for HER2-positive breast cancer, by exploiting the concomitant administration of trastuzumab, taxane and anthracycline, while restraining cardiac toxicity with use of liposomal doxorubicin, and by adding metformin, based on preliminary evidence of antitumor activity. PATIENTS AND METHODS: This multi-center, single-arm, two-stage phase II trial, assessed the safety and the activity of a new treatment regimen for HER2-positive, early or locally advanced breast cancer. Patients received six 21-day cycles of non-pegylated liposomal doxorubicin, 50 mg/m2 intravenously (i.v.) on day 1, docetaxel, 30 mg/m2 i.v. on days 2 and 9, trastuzumab, 2 mg/kg/week i.v. on days 2, 9, and 16 (with 4 mg/kg loading dose), in association with metformin 1000 mg orally twice daily. The primary endpoint was the rate of pathological complete response (pCR) in the breast and axilla (ypT0/is ypN0). A subgroup of patients performed a 3-deoxy-3-18F-fluorothymidine positron emission tomography (FLT-PET) at baseline and after one cycle. RESULTS: Among 47 evaluable patients, there were 18 pCR [38.3%, 95% confidence interval (CI) 24.5-53.6%]. A negative estrogen-receptor status, high Ki67, and histological grade 3 were related with pCR, although only grade reached statistical significance. FLT-PET maximum standardized uptake value after one cycle was inversely related to pCR in the breast (odds ratio 0.29, 95% CI 0.06-1.30, p = 0.11). Toxicity included grade 3-4 neutropenia in 70% and febrile neutropenia in 4% of patients, grade 1-2 nausea/vomiting in 60%/38%, and grade 3 in 4%/2%, respectively, grade 1-2 diarrhea in 72%, and grade 3 in 6%. There were two cases of reversible grade 2 left-ventricular ejection-fraction decrease, and one case of sharp troponin-T increase. CONCLUSIONS: The concomitant administration of trastuzumab, liposomal doxorubicin, docetaxel, and metformin is safe and shows good activity, but does not appear to improve activity over conventional sequential regimens.

Benefit from anthracyclines in relation to biological profiles in early breast cancer.

There are no validated predictors of benefit from anthracyclines. We compared cyclophosphamide, methotrexate, 5-fluorouracil (CMF), and epirubicin in different sequences with CMF alone in a phase III trial on operable breast cancers. Outcomes were analyzed in relation to tumor biological profiles to identify potential predictors of the efficacy of different treatments/drug combinations. Patients with N- or 1-3N+ tumors, were randomized to receive (a) epirubicin (4 cycles) followed by CMF (4 cycles); (b) CMF (4 cycles) followed by epirubicin (4 cycles), or (c) CMF (6 cycles) alone. Immunohistochemical assessments of estrogen (ER) and progesterone (PgR) receptors, HER2 and Ki67 were available for 705 patients (arm A/B/C: 276/269/160). Prognostic and predictive relevance was analyzed by log-rank tests and Cox models. Ki67 > 20 % and absent/low expression of ER and PgR were associated with worsen disease-free (DFS) and overall survival (OS). In patients with triple negative tumors (ER-, PgR-, HER2-), epirubicin-containing regimens yielded better DFS (HR 0.33, 95 % CI 0.17-0.62, P = 0.0007) and OS (HR 0.24, 95 % CI 0.10-0.57, P = 0.001) compared with CMF alone, whereas no differences were found in patients with HER2-positive (HER2+, ER-, PgR-) subtype. Treatment by subtype interaction (HER2-positive vs. others) was significant for DFS (χ (2) = 6.72, P = 0.009). In triple unfavorable (ER-, PgR-, Ki67 > 20 %) tumors, the use of epirubicin yielded better DFS (HR 0.45,95 % CI 0.26-0.78, P = 0.005) and OS (HR 0.30, 95 % CI 0.15-0.63, P = 0.001). Epirubicin-containing regimens seem to be superior to CMF alone in patients with highly proliferating, triple negative or triple unfavorable tumors.

Addition of 5-fluorouracil to doxorubicin-paclitaxel sequence increases caspase-dependent apoptosis in breast cancer cell lines.

INTRODUCTION: The aim of the study was to evaluate the activity of a combination of doxorubicin (Dox), paclitaxel (Pacl) and 5-fluorouracil (5-FU), to define the most effective schedule, and to investigate the mechanisms of action in human breast cancer cells. METHODS: The study was performed on MCF-7 and BRC-230 cell lines. The cytotoxic activity was evaluated by sulphorhodamine B assay and the type of drug interaction was assessed by the median effect principle. Cell cycle perturbation and apoptosis were evaluated by flow cytometry, and apoptosis-related marker (p53, bcl-2, bax, p21), caspase and thymidylate synthase (TS) expression were assessed by western blot. RESULTS: 5-FU, used as a single agent, exerted a low cytotoxic activity in both cell lines. The Dox-->Pacl sequence produced a synergistic cytocidal effect and enhanced the efficacy of subsequent exposure to 5-FU in both cell lines. Specifically, the Dox-->Pacl sequence blocked cells in the G2-M phase, and the addition of 5-FU forced the cells to progress through the cell cycle or killed them. Furthermore, Dox-->Pacl pretreatment produced a significant reduction in basal TS expression in both cell lines, probably favoring the increase in 5-FU activity. The sequence Dox-->Pacl-->48-h washout-->5-FU produced a synergistic and highly schedule-dependent interaction (combination index < 1), resulting in an induction of apoptosis in both experimental models regardless of hormonal, p53, bcl-2 or bax status. Apoptosis in MCF-7 cells was induced through caspase-9 activation and anti-apoptosis-inducing factor hyperexpression. In the BRC-230 cell line, the apoptotic process was triggered only by a caspase-dependent mechanism. In particular, at the end of the three-drug treatment, caspase-8 activation triggered downstream executioner caspase-3 and, to a lesser degree, caspase-7. CONCLUSION: In our experimental models, characterized by different biomolecular profiles representing the different biology of human breast cancers, the schedule Dox-->Pacl-->48-h washout-->5-FU was highly active and schedule-dependent and has recently been used to plan a phase I/II clinical protocol.

Prognostic relevance of mitotic activity in patients with node-negative breast cancer.

The prognostic relevance of mitotic activity was analyzed in a series of 306 patients with node-negative breast cancer treated with locoregional therapy alone, until early relapse. Mitotic activity was evaluated as the number of mitotic figures per 10 high-power fields (mitotic activity index) or per 1000 tumor cells (mitotic index). Counting was carried out blindly by two observers. A high correlation was observed between the two determinations (r(s) =.96, P <.001). For clinical analysis, three mitotic activity index subgroups (mitotic figures/field