Preoperative second-line chemotherapy induces objective responses in primary breast cancer

Preoperative chemotherapy in patients with primary breast cancer results in high response rates, allowing breast-conserving surgery in patients primarily not suitable for this procedure. Tumors of patients with histologically proven breast cancer that fail to respond to preoperative chemotherapy are thought to be chemotherapy resistant. We questioned this hypothesis and treated 13 patients who did not respond to preoperative anthracycline-containing first-line treatment.

Eight patients received a combination therapy consisting of epidoxorubicin and docetaxel as neoadjuvant first-line treatment and were treated with CMF as preoperative second-line chemotherapy. The other five patients did not respond to first-line FEC and were given paclitaxel or docetaxel as second-line treatment.

A major response to treatment was observed in 10 of 13 patients (77%) during preoperative second-line therapy: one patient (8%) achieved pathological complete response (pCR) and nine patients (69%) partial response (PR). Three patients (23%) had stable disease (SD), and no patient had progressive disease (PD). Eight patients (62%) could undergo breast-conserving surgery.

We conclude that it is possible to achieve objective responses including pCR with potentially non-cross-resistant neoadjuvant second-line therapy, leading to breast-conserving surgery in a high proportion of patients. Thus, preoperative second-line chemotherapy appears to be justified when breast conservation is an important treatment goal and may have potential in improved tailoring of neoadjuvant treatments.