Tamoxifen as an Adjuvant Agent For Ductal Carcinoma In Situ (DCIS)
by Michael D. Lagios, MD, 11/2012
Tamoxifen has been considered a standard adjuvant agent, for local control in DCIS patients undergoing breast conservation with or without irradiation. This viewpoint derived from the initial results of NSABP-B24, which claimed a significant benefit for ipsilateral local control and contralateral chemoprevention.
Both trials, which had employed tamoxifen as an adjuvant agent in DCIS patients (NSABP-B24 and UK/ANZ) have been updated in 2011 (Wapnier et al 2011 and Cuzick et al 2011), and have initiated some pointed commentary (Cadiz and Kuerer 2012; Warrick and Allred 2012).
Wapnir et al 2011 presented the update of the entire trial with a median 163 month followup (Figure 2). There was no statistically significant benefit of TAM for preventing an ipsilateral in situ event (eight fewer events with TAM), but there was a small benefit in preventing an invasive event (22 fewer invasive events).
Cuzick et al 2012 provided an update of the UK/ANZ trial. There was no significant difference between patients with or without tamoxifen therapy either for ipsilateral or contralateral events, in situ or invasive, in those patients who had been treated with radiation therapy (Figure 3).
Warrick and Allred in their editorial piece conclude that tamoxifen is probably overused, and advocate more selective use. They particularly note that the major benefit would be seen in patients who are younger (premenopausal) with extensive high-grade disease and/or narrow margins, and clearly only those that are ER positive.
In conclusion, the clinical benefit of tamoxifen intervention based on the randomized trials is meager at best. There appears to be no benefit, at least in the UK/ANZ trial for tamoxifen amongst irradiated patients, and the benefits when claimed are very small.
Allred D.C. et al, 2012. Adjuvant tamoxifen reduces subsequent breast cancer in women with estrogen receptor–positive ductal carcinoma in situ: A study based on NSABP protocol B24. J. Clin. Oncol. 30:1268-1273.
Cadiz F. and Kuerer H., 2012. Review of: Tamoxifen added to radiotherapy and surgery for the treatment of ductal carcinoma in situ of the breast: A meta-analysis of two randomized trials. Breast Diseases: A Year Book Quarterly, 23 (2), 163-164.
Cuzick J. et al, 2011. Effect of tamoxifen and radiotherapy in women with locally excised ductal carcinoma in situ: Long-term results from the UK/ANZ DCIS trial. Lancet Oncology 12:21-29.
Wapnir IL et al 2011. Long-term outcomes of invasive ipsilateral breast tumor recurrences after lumpectomy and NSABP B-17 and B-24, randomized clinical trials for DCIS. J. Natl. Cancer Institute, 103: 478-488.
Warrick J. and Allred D.C., 2012. Determining which patients with ductal carcinoma in situ should receive tamoxifen. Editorial, Breast Diseases: A Year Book Quarterly, 23 (1), 23-25. Diagnost