Safety and Tolerability of Docetaxel, Cyclophosphamide, and Trastuzumab Compared to Standard Trastuzumab-Based Chemotherapy Regimens for Early-Stage Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer

Purpose: We evaluated the tolerability and cardiac safety of docetaxel, cyclophosphamide, and trastuzumab (TCyH) for the treatment of early-stage human epidermal growth factor receptor 2 (HER2)-positive breast cancer and compared to the standard trastuzumab-based chemotherapy regimens doxorubicin with cyclophosphamide followed by paclitaxel and trastuzumab (ACTH) and docetaxel, carboplatin, and trastuzumab (AC-TH). Methods: We retrospectively reviewed early-stage, resectable, HER2-positive breast cancer patients treated with trastuzumab-based chemotherapy at a single comprehensive cancer center between 2004 and 2011. Patient characteristics, comorbidities, relative dose intensity (RDI) of each regimen, tolerability, and cardiac toxicity were evaluated. Results: One hundred seventy-seven patients were included in the study (AC-TH, n=114; TCaH, n=39; TCyH, n=24). TCyH was solely administered in the adjuvant setting, whereas two-thirds of the AC-TH and TCaH groups were administered postoperatively. Patients treated with TCyH tended to have a more significant underlying cardiac history, higher Charlson comorbidity index, and were of an earlier stage. All patients treated with TCyH received granulocyte colony stimulating factor primary prophylaxis. No febrile neutropenia or grade 3 hematologic toxicity was observed in the TCyH group as compared to the AC-TH and TCaH groups. There were no significant differences in the rates of early termination, hospitalization, dose reduction, or RDI between the regimens. The symptomatic congestive heart failure rate between AC-TH, TCaH, and TCyH groups was not significantly different (4.4% vs. 2.6% vs. 8.3%, respectively, p=0.57): There was also no significant difference in the rate of early trastuzumab termination between patients treated with each regimen. Conclusion: TCyH is well tolerated and should be investigated as an alternative adjuvant chemotherapy option for patients who are not candidates for standard trastuzumab-containing regimens. Larger clinical trials are necessary to support the wider use of TCyH as an adjuvant regimen.