BABC present with adverse clinical and histopathologic features when compared with cases not associated with BRCA mutations. However, the prognosis of BABC appears to be similar to that of nonassociated cancer. Further studies of incident cases are necessary to define the independent prognostic significance of germline BRCA mutations.

Paclitaxel demonstrates activity against metastatic breast cancer when administered over 96 hours to patients with disease that recently had progressed during short taxane exposure. Delayed paclitaxel clearance and consequent increased toxicity occurred in patients with hepatic dysfunction. The activity observed supports preclinical data that suggest variability in efficacy and resistance patterns to paclitaxel based on duration of exposure.

Purpose The CLEOPATRA (Clinical Evaluation of Trastuzumab and Pertuzumab) study demonstrated superior progression-free survival (PFS) and overall survival when pertuzumab was added to trastuzumab and docetaxel. Paclitaxel given once per week is effective and less toxic than docetaxel. We performed a phase II study to evaluate the efficacy and safety of pertuzumab and trastuzumab with paclitaxel given once per week. Patients and Methods Patients with metastatic human epidermal growth factor receptor 2–positive breast cancer with zero to one prior therapy were enrolled. Treatment consisted of paclitaxel 80 mg/m2 once per week plus trastuzumab (8 mg/kg loading dose → 6 mg/kg) once every 3 weeks plus pertuzumab (840 mg loading dose → 420 mg) once every 3 weeks, all given intravenously. The primary end point was 6-month PFS assessed by Kaplan-Meier methods. Results From January 2011 to December 2013, we enrolled 69 patients: 51 (74%) and 18 (26%) treated in first- and second-line metastatic settings, respectively. At a median follow-up of 21 months (range, 3 to 38 months), 6-month PFS was 86% (95% CI, 75% to 92%). The median PFS was 19.5 months (95% CI, 14 to 26 months) overall. PFS was 24.2 months (95% CI, 14 months to not reached [NR]) and 16.4 months (95% CI, 8.5 months to NR) for those without and with prior treatment, respectively. At 1 year, Kaplan-Meier PFS was 70% (95% CI, 56% to 79%) overall, 71% (95% CI, 55% to 82%) for those without prior therapy, and 66% (95% CI, 40% to 83%) for those with prior therapy. Treatment was well-tolerated; there was no febrile neutropenia or symptomatic left ventricular systolic dysfunction. Conclusion Paclitaxel given once per week with trastuzumab and pertuzumab is highly active and well tolerated and seems to be an effective alternative to docetaxel-based combination therapy.

Paclitaxel's clinically significant activity against metastatic breast cancer extends to patients with many prior chemotherapy regimens. The lack of impact of prior doxorubicin therapy on the likelihood of subsequent response to paclitaxel suggests an important role for this agent in the treatment of refractory metastatic breast cancer.

Dose-dense AC followed by P/T followed by T is feasible and is not likely to increase the incidence of cardiac events compared to established regimens.