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.