Impact of estrogen receptor expression and other clinicopathologic features on tamoxifen use in ductal carcinoma in situ

BACKGROUND: Recent data have demonstrated that benefit from adjuvant tamoxifen therapy for patients with ductal carcinoma in situ (DCIS) is limited to estrogen receptor (ER)-positive lesions. The objective of the current study was to correlate clinicopathologic features of DCIS with ER expression and the impact of this information on tamoxifen counseling. METHODS: Women with DCIS who were treated from 2001 to 2004 were evaluated. Routine ER staining was initiated in January 2003. RESULTS: Ninety-four women (mean age, 57.6 years) were analyzed. The mean DCIS size was 0.98 cm. ER-staining was performed in 55 lesions, and 76% were ER-positive. All Grade 1 and 2 DCIS lesions were ER-positive, compared with 54% of high-grade lesions (P<.001); no other clinicopathologic feature significantly predicted ER status. Overall, 58 patients (62%) were offered tamoxifen, and the rates were similar for the pre-ER and post-ER staining periods. In the pre-ER staining period, surgical treatment and grade were associated with offering tamoxifen (75% of patients who underwent breast conservation vs. 40% of patients who underwent mastectomy; P = .03; 78% of patients with Grade 1 or 2 lesions vs. 45% of patients with Grade 3 lesions; P = .04). In the post-ER staining period, however, only ER status was correlated significantly with offering tamoxifen (71% of patients with ER-positive lesions vs. 31% of patients with ER-negative lesions; P = .01). Approximately 66% of patients who were offered tamoxifen agreed to treatment (approximately 33% of the total DCIS study sample). No clinicopathologic features predicted for tamoxifen acceptance by patients in either the pre-ER or post-ER staining periods. CONCLUSIONS: Seventy-five percent of DCIS lesions were ER-positive. ER staining significantly influenced the likelihood that clinicians would offer tamoxifen to patients with DCIS, but it had no impact on whether patients accepted treatment.