Overall Survival After Cyclophosphamide, Adriamycin, 5-FU, And Tamoxifen (CAFT) Is Superior To T Alone In Postmenopausal, Receptor (+), Node (+) Breast Cancer: New Findings From Phase III Southwest Oncology Group Intergroup Trial S8814 (INT-0100)
Heather Jones, MD
University of Pennsylvania Cancer
Last Modified: May 15, 2001
Presenter: Kathy Albain
Affiliation: Loyola Univ. Med. Center, Maywood, IL
The treatment of older women with breast cancer presents many unique treatment issues. One such issue is the use of anthracyclines to treat older patients who are receptor positive and node positive. The objectives of INT-0100 were to determine 1) if CAFT was superior to the 1988 standard of T alone in postmenopausal women with node (+), receptor (+) disease; and 2) if CAF followed by T was better than concurrent CAFT. The main CAFT v. T comparison (2 CAF arms combined) met early reporting criteria for disease-free survival (DFS) in 1996. There was a DFS advantage for CAFT at 4 years presented at ASCO, 1997. Now SWOG presents a more mature analysis of the main question after 4 more years of follow-up, including new overall survival (S) results. The second objective has not met statistical reporting criteria.
Materials and Methods:
- There were 1477 eligible patients randomized, by design fewer were accrued to T (361) than to CAF followed by T (566) or concurrent CAF+T (550).
- T was given for 5 years after standard CAF, 6 cycles.
- Stratification was by number of nodes, PgR status and interval from surgery.
- The CAF and CAFT groups were combined to answer the chemotherapy question.
- There was good balance for prognostic factors between the two groups
- There was a 2% incidence of CHF in a recent analysis of patients on CAFT alive and disease- free at 1 year. Among all eligible patients, endometrial cancers were reported in 3 (0.8%) on T and 10 (0.9%) on CAFT. Overall, there were 6 Myelodysplastic syndromes and 3 AML.
- The DFS benefit from CAFT over T remains strongly significant, with p=.0001 after adjustment for stratification factors. The absolute improvement in DFS from CAFT at 5 years is now 9% (76% v. 67%).
- After the first 4 years of follow-up the survival curves diverge, with CAFT superior to T (adjusted p = 0.007)
- Currently there is a 5% absolute survival benefit from CAFT at 5 years (84% v. 79%).
CAF plus Tamoxifen significantly improves long- term DFS and after prolonged follow-up, and offers a definite survival benefit over T for postmenopausal women with node (+), receptor(+) breast cancer.
This is a very good study that nicely demonstrates the benefit of CAF and its associated toxicity. However, this study evaluated the standard of care for adjuvant therapy for this population in 1988. Of note, HER2 status is not a part of the treatment model for this study. In addition, there are less toxic agents, such as the Taxanes, Trastuzumab, and Aromatase inhibitors, which are being evaluated in this population.
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