Five versus more than five years of tamoxifen for lymph node-negative breast cancer: updated findings from the National Surgical Adjuvant Breast and Bowel Project B-14 randomized trial.

Abstract

BACKGROUND:

Previously reported information from B-14, a National Surgical Adjuvant Breast and Bowel Project (NSABP) randomized, placebo-controlled clinical trial, demonstrated that patients with estrogen receptor (ER)-positive breast cancer and negative axillary lymph nodes experienced a prolonged benefit from 5 years of tamoxifen therapy. When these women were rerandomized to receive either placebo or more prolonged tamoxifen therapy, they obtained no additional advantage from tamoxifen through 4 years of follow-up. Because the optimal duration of tamoxifen administration continues to be controversial and because there have been 3 more years of follow-up and a substantial increase in the number of events since our last report, an update of the B-14 study is appropriate.

METHODS:

Patients (n = 1172) who had completed 5 years of tamoxifen therapy and who were disease free were rerandomized to receive placebo (n = 579) or tamoxifen (n = 593). Survival, disease-free survival (DFS), and relapse-free survival (RFS) were estimated by the Kaplan-Meier method; the differences between the treatment groups were assessed by the log-rank test. Relative risks of failure (with 95% confidence intervals) were determined by the Cox proportional hazards model. P values were two-sided.

RESULTS:

Through 7 years after reassignment of tamoxifen-treated patients to either placebo or continued tamoxifen therapy, a slight advantage was observed in patients who discontinued tamoxifen relative to those who continued to receive it: DFS = 82% versus 78% (P =.03), RFS = 94% versus 92% (P =.13), and survival = 94% versus 91% (P =.07), respectively. The lack of benefit from additional tamoxifen therapy was independent of age or other characteristics.

CONCLUSION:

Through 7 years of follow-up after rerandomization, there continues to be no additional benefit from tamoxifen administered beyond 5 years in women with ER-positive breast cancer and negative axillary lymph nodes.

• Authors: B Fisher, J Dignam, J Bryant, N Wolmark
• Journal: Journal of the National Cancer Institute (J Natl Cancer Inst) Vol. 93 Issue 9 Pg. 684-90 (May 02 2001) ISSN: 0027-8874 [Print] United States
• PMID: 11333290 (Publication Type: Clinical Trial, Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Estrogen Antagonists
• Tamoxifen

Topics

• Adult
• Aged
• Breast Neoplasms (drug therapy, mortality)
• Disease-Free Survival
• Estrogen Antagonists (therapeutic use)
• Female
• Humans
• Lymphatic Metastasis
• Middle Aged
• Tamoxifen (therapeutic use)
• Time Factors