Abstract A62: Secular trends and disparity of adjuvant hormone therapy use for ductal carcinoma in situ: National Cancer Database, 1998–2007

Abstract

Abstract Background: Randomized trials have shown clinical benefit for tamoxifen for patients with ductal carcinoma in situ (DCIS). We surveyed the secular trend and disparities of adjuvant hormone therapy (AHT) utilization for DCIS for the decade following dissemination of these trials. Methods: We utilized the National Cancer Database, a joint project of the American College of Surgeons and the American Cancer Society to examine secular trends of AHT use among 1,735,160 breast cancer patients diagnosed with breast cancer during 1998–2007. Trends of AHT use were evaluated in DCIS cases, and we stratified the analysis by race/ethnicity, age of diagnosis, and estrogen receptor (ER)/progresterone receptor (PR) status. ER/PR status was available for 2004–2007 only. The general estimating equation (GEE) model with logit link was performed to assess the odds of AHT treatment as a function of the aforementioned variables, clustering on facility to account for within-group correlations. Results: 258,593 DCIS and 1,360,235 invasive breast cancer cases were included in the analysis. The use of AHT has increased in DCIS patients over time, from 11.7% in 1998, to 23.6% in 1999, and 29.7% in 2007 despite only a 4% increase in the number of DCIS cases over the same time period. Among ER/PR-positive DCIS patients, 37.2% received AHT, whereas only 6.9% ER/PR-negative patients received AHT. Among the ER/PR-positive DCIS patients, we observed a significant disparity of AHT use by race/ethnicity in 2004, but this disparity lost significance in 2006 and 2007; 36.0% white, 31.4% black and 29.9% Hispanic patients used AHT treatment in 2004 (p=0.001), compared to 38.6% white, 37.1% black and 39.5% Hispanic patients in 2007 (p=0.4). Racial disparity also diminished in the GEE model, which removes between-facility differences. AHT use was significantly less in academic/research oriented facilities than in community hospitals (OR=0.74, 95% CI: 0.66–0.83, p<0.0001), and it also varied across facility location. In addition, AHT use varied by age of diagnosis: compared with ER/PR-positive patients at age 50–59, the OR for patients <40 years was 0.58 (95% CI: 0.52–0.65), for patients 40–49 years 0.89 (95% CI: 0.85–0.95), patients 60–69years 0.95 (95% CI:0.90-1.00), patients 70–79 years 0.72 (95% CI: 0.67–0.77), and for patients 80 years or older 0.40 (95% CI: 0.37–0.45). For ER/PR-positive patients 40–69 years old the use of AHT was 39.9%. Conclusions: AHT utilization nearly doubled from 1998 to 1999 presumably because of the randomized trials but has only slightly increased from 1999–2007. Racial disparities in AHT use among DCIS patients disappeared from 2004 to 2007 but AHT use still varies by patient age, facility type and location. Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):A62.