"Doxorubicin/Cyclophosphamide Followed by Paclitaxel Inferior to Epirubicin-Based Therapy in Operable Breast Cancer: Presented at SABCS"
By Emma Hitt, PhD
SAN ANTONIO, TX -- December 18, 2006 -- In women with operable breast cancer, doxorubicin/cyclophosphamide followed by paclitaxel (AC/T) given every 3 weeks demonstrated inferiority in terms of relapse-free survival compared with 2 epirubicin-based regimens, according to interim findings of a phase 3 study.
Margot Burnell, MD, medical oncologist, department of oncology and department of internal medicine, Atlantic Health Sciences Corporation, Saint John, New Brunswick, Canada, reported the findings here on December 17[th at the 29th Annual San Antonio Breast Cancer Symposium (SABCS).
The National Cancer Institute of Canada's (NCIC) MA.21 trial is comparing 3 chemotherapy combinations involving epirubicin or doxorubicin in premenopausal and early postmenopausal women with lymph-node-positive and high-risk lymph-node-negative breast cancer.
Specifically, the 3 regimens being compared in the trial are the following: cyclophosphamide/epirubicin/fluorouracil (CEF); epirubicin/cyclophosphamide followed by paclitaxel (EC/T); doxorubicin/cyclophosphamide followed by paclitaxel (AC/T). Filgrastim and epoetin alpha were administered concurrently with EC/T.
CEF is used widely in Canada for women with high-risk operable breast cancer, whereas in the United States, AC/T is used more commonly. The current study asked whether adding 3 months of the taxane paclitaxel after dose-dense EC would improve outcomes compared with CEF or AC/T.
The analysis included a total of 2,104 women, aged 60 years or younger, with node-positive or high-risk node-negative breast cancer. All underwent lumpectomy or mastectomy. Patients were randomized to receive 1 of the 3 chemotherapy regimens.
Median follow-up of surviving patients was 30.4 months; 79 recurrences were observed with CEF, versus 70 with dose-dense EC/T, and 112 with AC/T.
Relative to the doxorubicin-containing regimen, the risk of recurrence was significantly reduced with the epirubicin-containing regimens. For AC/T versus CEF, the hazard ratio (HR) for recurrence was 1.49 (95% confidence interval [CI], 1.12-1.99; P = .005) and for AC/T versus EC/T, it was 1.68 (95% CI, 1.25-2.27; P = .0006). The study detected no difference between the 2 epirubicin-containing regimens, HR = 0.89 (95% CI, 0.64-1.22; P = .46).
Corresponding 3-year recurrence-free survival (RFS) rates for CEF, EC/T, and AC/T were 90.1, 89.5, and 85.0%, respectively.
"Taxanes may not be necessary as adjuvant therapy for all women," Dr. Burnell noted during the presentation, "whereas a dose-dense approach with an anthracycline appears to improve outcomes."
The researchers also reported that most of the benefit with epirubicin-based therapy was observed in the approximately 30% of women with estrogen receptor-negative tumors.
The study received commercial support from Pfizer, Bristol-Myers Squibb, Amgen, Janssen Ortho, and Ortho Biotech.
[Presentation title: A Randomized Trial of CEF Versus Dose Dense EC Followed By Paclitaxel Versus AC Followed By Paclitaxel in Women With Node Positive or High Risk Node Negative Breast Cancer, NCIC CTG MA.21: Results of an Interim Analysis. Abstract 51]
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