Journal of clinical oncology : official journal of the American Society of Clinical Oncology 2012-04-20
Adjuvant tamoxifen reduces subsequent breast cancer in women with estrogen receptor-positive ductal carcinoma in situ: a study based on NSABP protocol B-24.
Abstract
Purpose
The NSABP (National Surgical Adjuvant Breast and Bowel Project) B-24 study demonstrated significant benefit with adjuvant tamoxifen in patients with ductal carcinoma in situ (DCIS) after lumpectomy and radiation. Patients were enrolled without knowledge of hormone receptor status. The current study retrospectively evaluated the relationship between receptors and response to tamoxifen.
Patients and methods
Estrogen (ER) and progesterone receptors (PgR) were evaluated in 732 patients with DCIS (41% of original study population). An experienced central laboratory determined receptor status in all patient cases with available paraffin blocks (n = 449) by immunohistochemistry (IHC) using comprehensively validated assays. Results for additional patients (n = 283) determined by various methods (primarily IHC) were available from enrolling institutions. Combined results were evaluated for benefit of tamoxifen by receptor status at 10 years and overall follow-up (median, 14.5 years).
Results
ER was positive in 76% of patients. Patients with ER-positive DCIS treated with tamoxifen (v placebo) showed significant decreases in subsequent breast cancer at 10 years (hazard ratio [HR], 0.49; P < .001) and overall follow-up (HR, 0.60; P = .003), which remained significant in multivariable analysis (overall HR, 0.64; P = .003). Results were similar, but less significant, when subsequent ipsilateral and contralateral, invasive and noninvasive, breast cancers were considered separately. No significant benefit was observed in ER-negative DCIS. PgR and either receptor were positive in 66% and 79% of patients, respectively, and in general, neither was more predictive than ER alone.
Conclusion
Patients in NSABP B-24 with ER-positive DCIS receiving adjuvant tamoxifen after standard therapy showed significant reductions in subsequent breast cancer. The use of adjuvant tamoxifen should be considered for patients with DCIS.
Related Questions
In what scenarios do you consider omitting adjuvant endocrine therapy after lumpectomy for DCIS?
NSABP 24, 35 Trials. Adjuvant hormone therapy prolongs DFS.
How does the potential for a patient to accept or forego adjuvant tamoxifen factor into your recommendations on adjuvant RT for DCIS?
In the RTOG 9804 trial, the only factors predicting for local control in the breast were the use of radiation and of tamoxifen. So for women who have hormone positive tumors, I strongly advocate for some treatment in addition to the lumpectomy.I find the results of the UK, Australia, and New Zealand...
Would you give adjuvant anti-hormonal therapy after bilateral mastectomies for multifocal/multicentric high grade DCIS?
No. Since DCIS does not metastasize, the purpose of endocrine therapy, with either tamoxifen or and AI after DCIS, is to decrease the risk of local recurrence and new breast cancers. Having bilateral mastectomy decreases the risk by >90%, such that the additional benefit of preventive endocrine ther...
Would you consider using tamoxifen in ER-negative DCIS?
In the placebo-controlled NSABP-B24 trial, tamoxifen reduced the risk of ipsilateral and contralateral second events by 30% and 52%, respectively, when added to BCS and radiation. In a reanalysis of a subset of participants with estrogen receptor expression information, this benefit was most apparen...