Shorter-duration FEC3-D3 Neoadjuvant Chemo has Similar Clinical Response Rates to AC4-D4

SAN ANTONIO—A short sequential regimen of neoadjuvant chemotherapy, FEC3-D3 (3 cycles of FEC followed by 3 cycles of docetaxel), offers comparable pathological complete response (pCR) rates to those achieved with the longer-duration regimen AC4-D4 (4 cycles of doxorubicin plus cyclophosphamide, followed by 4 cycles of docetaxel) among women with node-positive breast cancer, according to efficacy and toxicity findings from a prospective, randomized, single-center comparative phase 3 clinical study (NCT02001506). The findings were presented at the 2015 San Antonio Breast Cancer Symposium.¹

“Compared to AC4-D4, shorter-duration of FEC3-D3 neoadjuvant chemotherapy showed similar efficacy of pCR rate,” reported lead study author Jeong Eun Kim, MD, of the Asan Medical Center, University of Ulsan College of Medicine in Korea.

Adding a taxane to anthracycline-based chemotherapy improves neoadjuvant outcomes in breast cancer. However, it is not entirely clear how efficacies of 2 different-duration sequential regimens, AC4-D4 and FEC3-D3, compare.

The researchers therefore analyzed data from 173 patients who had been diagnosed with clinical stage 2 or 3 breast cancer or tumors with diameters of 1.5 cm or greater and who had histologically confirmed lymph node involvement. The patients had been stratified by hormone-receptor and HER2-expression status, and then randomly assigned to receive either AC4-D4 (80 patients) or 3 cycles of FEC3-D3 (93 patients).

Pathological complete response (pCR) was defined as the absence of invasive disease in the breast and axillary lymph nodes. A total of 76 of 80 patients in the AC4-D4 group achieved clinical responses, including 9 complete responses (CR) and 67 partial responses (PR).

Among patients receiving AC4-D4, 14/80 patients achieved pCR, compared to 12/93 in the FEC3-D3 group. In the FEC3-D3 group, 80 of 93 patients experienced a clinical response (7 CR; 73 PR).

“Seventeen non-hematologic severe adverse events were reported,” said Dr Kim. “The most common and important adverse event was febrile neutropenia in both arms.”

Reference

1. Kim JE, Ahn J-H, Jung KH, et al. A randomized phase lll trial of neoadjuvant sequential chemotherapy with 4 cycles of adriamycin plus cyclophosphamide followed by 4 cycles of docetaxel (AC4-D4) versus shorter 3 cycles of FEC followed by 3 cycles of docetaxel (FEC3-D3) in node-positive breast cancer (Neo-Shorter): First report of efficacy & toxicity profile. Oral presentation at: San Antonio Breast Cancer Symposium 2015; December 9, 2015; San Antonio, TX.