Presentation Abstract

Abstract Number: 5639
Presentation Title: Preoperative concurrent paclitaxel and radiation in locally advanced breast cancer (LABC): Five-year outcomes on 105 patients
Presentation Time: Wednesday, Apr 21, 2010, 8:00 AM -11:00 AM
Location: Exhibit Hall A-C, Poster Section 32
Poster Section: 32
Poster Board Number: 5
Author Block: Sylvia Adams1, A. Bapsi Chakravarthy2, Martin Donach1, Stella Lymberis1, Baljit Singh1, Tsivia Hochman1, Judith D. Goldberg1, Joshua A. Bauer2, Darcy Spicer3, Jennifer A. Pietenpol2, Silvia C. Formenti1. 1New York University Cancer Institute, NYU School of Medicine, New York, NY; 2Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN; 3Kenneth Norris Jr Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, CA
Abstract Body: Purpose: A prospective trial of preoperative concurrent paclitaxel and radiation for patients with LABC was conducted at three academic institutions. Five-year local and systemic control rates are reported.
Patients and Methods: 105 patients with LABC were treated with concurrent neoadjuvant paclitaxel and radiation. Paclitaxel was administered at 30 mg/m2 intravenously twice a week for 10-12 weeks. Daily radiotherapy was delivered to the breast, axillary and supraclavicular lymph nodes during weeks 2-7, at 1.8 Gy per fraction to a total dose of 45 Gy followed by a boost of 14 Gy at 2 Gy per fraction to the originally palpable tumor. Weekly trastuzumab (2mg/kg) was added for 8 more recent patients whose tumor over-expressed Her-2/neu. At one of the three institutions preoperative paclitaxel (3 cycles of 175 mg/m2 q 3 weeks) was also administered prior to chemo-radiation to 36 patients. Pathologic response was defined as complete response (pCR) in the absence of invasive cancer in breast or lymph nodes; partial response (pPR) as the persistence of < 10 microscopic foci of invasive carcinoma in breast or lymph nodes. After surgery additional systemic therapy was left to the discretion of the treating physician.
Results: Pathological response (pCR and pPR) after neoadjuvant chemo-radiation was achieved in 36/105 patients (34.3%, 95% confidence interval: 25.3% - 44.2%). 30/105 patients underwent breast-conserving surgery after neoadjuvant chemo-radiation (28.6%), while 74 underwent mastectomy. One patient progressed during therapy and did not undergo surgery.
With a median follow up of 60 months and a maximum of 137 months, the median survival has not been reached. The estimated 5-year overall cumulative survival (OS) is 71.6% (95% confidence interval: 60.5% - 80.1%). Local recurrence occurred in 4/105 patients (3.8%): in 3/4 synchronously with or following systemic recurrence. Five patients (4.8%) developed contra-lateral breast cancer.
Patients without a pathologic response had a higher risk of recurrence or death than patients who had a pathologic response (hazard ratio = 2.86, logrank p-value=0.009); similarly, survival was shorter (hazard ratio = 4.28, logrank p-value=0.003). The 5-year estimated OS for non-responders was 61.6% compared with 87.9% for responders.
A separate analysis of patients who received additional preoperative paclitaxel before chemo-radiation showed a pathologic response rate of 41.7% (15/36 patients, 95% confidence interval: 25.5% to 59.2%); with an estimated 5-year OS of 63.9% (95% confidence interval: 46.1% - 77.2%). Conclusion: This series of 105 patients with LABC treated with concurrent paclitaxel and radiation demonstrated a 71.6% 5-year OS and 96% local control rate. Pathological response to concurrent paclitaxel and radiation was associated with a significantly better 5-year survival.