MedWire News: Addition of chemotherapy to standard tamoxifen treatment for postmenopausal women with node-positive breast cancer significantly improves disease-free survival, and this benefit is maximized when the tamoxifen follows chemotherapy, US researchers report in The Lancet.
In a randomized trial of 1558 women with hormone-receptor-positive, node-positive breast cancer, Kathy Albain (Loyola University Medical Center, Maywood, Illinois) and colleagues tested two major objectives. These were whether disease-free survival is longer with chemotherapy (cyclophospamide, doxorubicin, and fluorouracil [CAF])given every 4 weeks for six cycles plus 5 years of daily tamoxifen than with tamoxifen alone; and whether disease-free survival was longer with CAF followed by tamoxifen (CAF-T) than with CAF plus concurrent tamoxifen (CAFT).
After a maximum follow-up of 13 years, the researchers estimated that at 10 years 60% of women treated with CAF-T were free from recurrence or death due to any cause, compared with 53% on CAFT and 48% on tamoxifen alone. The proportions of women alive at 10 years were 68%, 62%, and 60%, respectively, for CAF-T, CAFT, and tamoxifen.
Multivariate analysis adjusted for potential confounders revealed that women in the combined CAF-T/CAFT groups were 24% less likely to experience a breast cancer recurrence or death than those given tamoxifen alone, and 17% more likely to survive. The difference between CAF-T and CAFT was not statistically significant, but favored CAF-T.
Adverse events such as neutropenia, congestive heart failure, leukemia, and thromboembolism were more frequent in the chemotherapy groups than in the tamoxifen only group.
Albain and co-authors conclude: “We believe that for postmenopausal women with few comorbidities who have a substantial risk of recurrence or death based on the prognostic profile of their tumors, the risk–benefit balance favors anthracycline-based chemotherapy followed by tamoxifen. However, characteristics of the tumor should also be factored into the risk–benefit ratio.”
“This study shows the necessity of long-term follow-up of adjuvant therapies to determine the outcomes of treatment,” they add.
A second article by Albain and colleagues, published in The Lancet Oncology, shows that a commonly used prognostic test (the 21-gene recurrence assay) predicted whether the patients in the first study would benefit from the addition of chemotherapy to tamoxifen.
The team found that patients in the CAF-T group with a high recurrence score (above 31) experienced significant improvements in disease-free survival, whereas patients with a low recurrence score (below 18) did not appear to benefit from chemotherapy, and could possibly be spared the toxic effects of such treatment.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2009
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