Treating Breast Cancer With Anthracyclines and Trastuzumab

Debu Tripathy, MD, Co-Leader, Women's Cancer Program, Norris Comprehensive Cancer Center, University of Southern California, discusses the treatment of breast cancer with anthracyclines and trastuzumab.

In the original randomized metastatic trial, patients received doxorubicin and cyclophosphamide (AC) with or without trastuzumab, while those who already had an anthracycline received paclitaxel with or without trastuzumab. The trial was positive in the anthracycline and taxane arm, but the impact was greater in the anthracycline arm and demonstrated greater toxicity. The oncology community has learned that anthracyclines and trastuzumab can be given together, though it is rarely done in the clinic.

There remains a lingering sense that anthracyclines are a better partner in the adjuvant setting, Tripathy says. In the BCIRG 006 trial, there was a non-anthracycline arm combined with trastuzumab using docetaxel and carboplatin, which showed equivalent results to the anthracycline plus trastuzumab arm. Numerically, there were more recurrences and deaths, but it was not statistically different, and the trial was not designed to compare the non-anthracycline and anthracycline-containing trastuzumab arms.

There was a study presented at the 2013 ASCO Meeting looking at paclitaxel and FEC (fluorouracil, epirubicin, and cyclophosphamide). In one arm, trastuzumab overlapped with epirubicin with anthracycline, while in the other arm, it did not. The pathologic complete response rates in this neoadjuvant trial were equal. Further, cardiac toxicity in this trial was low, leaving an unsettled question regarding safety.

Clinical Pearls

Tripathy says he feels torn at times with whether he should use an anthracycline-based regimen in high-risk patients.

• Anthracyclines and trastuzumab can be given together, but rarely are, due to increased toxicity
• There is a lingering sense that anthracyclines are a better partner for trastuzumab in the adjuvant setting
• Cardiac toxicity remains an issue for the combination of anthracyclines and trastuzumab