Weekly administration of bendamustine as salvage therapy in metastatic breast cancer: final results of a phase II study.

Single-agent bendamustine has shown promise in the treatment of metastatic breast cancer. As toxicity was low after weekly administration of this drug in other solid tumors, the present double-center phase II trial was conducted to evaluate the efficacy and toxicity of weekly bendamustine as salvage treatment in metastatic breast cancer. A total of 34 patients with anthracycline (88%) and/or taxane (71%) pretreated for metastatic breast cancer received 60 mg/m bendamustine on day 1, 8 and 15 every 28 days for six cycles. In addition, 10 patients with HER2/neu-overexpressing tumors either continued (five patients) or started treatment with 2 mg/kg trastuzumab weekly (loading dose 4 mg/kg) at study entry. Patients had predominantly visceral disease and had received one (88%) or two chemotherapy regimens for metastatic breast cancer. All patients were eligible for toxicity and 27 for response evaluation. No grade 3 or 4 hematologic toxicity occurred. Only three patients experienced grade 3 nonhematologic toxicity. Five patients (19%) reached a partial response. Stable disease for at least 6 months was achieved in eight patients, for a clinical benefit rate of 48%. The median progression-free survival and median overall survival were 6 months (range, 1-16) and 15 months (range, 2-28), respectively. We conclude that weekly bendamustine is a valid treatment option in patients with anthracycline-pretreated and/or taxanepretreated metastatic breast cancer; in particular, due to its low toxicity profile. Future trials should evaluate higher single doses of bendamustine in a weekly schedule.

Centrosomal aberrations in primary invasive breast cancer are associated with nodal status and hormone receptor expression.

Our purpose was to assess the presence of centrosomal aberrations as measured by immunohistochemistry in primary invasive breast cancer and their association with established and proposed prognostic factors. Tissue sections of 103 primary invasive breast cancers were examined using centrosome-specific antibodies to pericentrin and gamma-tubulin. At least 3 different tumor regions per case were examined to determine maximum centrosomal aberration levels, which represent the proportion of cells with abnormal centrosomes in the region with the highest percentage of cells with centrosomal aberrations. The chi(2) test was performed to evaluate the association of maximum centrosomal aberration levels with patient age; tumor size; nodal status; nuclear grade; hormone receptor and Her2/neu expression; proportion of Ki67-, p53- and Bcl-2-positive tumor cells; DNA index; S-phase fraction; and proliferation index. With pericentrin immunohistochemistry, maximum centrosomal aberration levels >35% were detectable in 92 of the 103 breast carcinomas (89%). We found a highly significant correlation of maximum centrosomal aberration levels above 35% with axillary nodal tumor involvement (p < 0.0001) and the absence of hormone receptors (p < 0.0001). In addition, there was a borderline significant relationship with age <50 years (p = 0.050) and Her2/neu overexpression (p = 0.050). Among node-negative patients, maximum centrosomal aberration levels >35% were also associated with an increased DNA index (p = 0.006). In a subset of patients, additional staining of centrosomes with a monoclonal anti-gamma-tubulin antibody essentially confirmed these results. In primary invasive breast cancer, centrosomal aberrations are associated with those factors predicting a more aggressive course of disease. This might indicate a fundamental role of centrosomal dysfunction in disease evolution, possibly as a result of chromosome missegregation during mitosis.