Relationship between Oncotype DX testing and the use of chemotherapy in high-risk patients (pts).

Abstract

6098 Background: CareFirst BlueCross BlueShield (CFBCBS) insurance network partnered with Cardinal Health Specialty Solutions (CHSS) to develop a cancer care pathway for network physicians in 2008. The program included a recommendation for molecular diagnostic testing with the Oncotype DX assay for pts with early-stage estrogen receptor-positive breast cancer. Based on NCCN guidelines, the pathway suggested adjuvant chemotherapy for all pts with Oncotype DX Recurrence Scores (RS) in the high-risk category. We aimed to determine the RS risk distribution among pts who received Oncotype DX testing and assess the patterns of care that followed. Methods: Using data from CFBCBS, CHSS proprietary claims software, and Genomic Health, we retrospectively identified a cohort of women with breast cancer who were treated on the CFBCBS clinical care pathways program from 8/2008 to 6/2011 and received Oncotype DX testing. We determined the number of pts with a RS value in the low- (RS <18), intermediate- (RS 18-30), and high-risk (RS ≥31) groups along with the number of pts who subsequently received chemotherapy in each category. Results: Of 1174 women who received Oncotype DX testing, 53% of pts were in the low-, 35% in intermediate-, and 12% in the high-risk groups. Five percent of low-, 41% of intermediate-, and 74% percent of pts in the high-risk category were treated with chemotherapy. Twenty-six percent of pts in the high-risk group did not receive chemotherapy. Conclusions: The proportionate use of chemotherapy in the low and intermediate risk groups was as expected based on adjuvant chemotherapy guidelines; however, the underuse of chemotherapy in 26% of high-risk pts was an unexpected finding. Further study is needed to determine: (1) why physicians avoided chemotherapy in 26% of high-risk pts; (2) the overall number of appropriate pts who underwent Oncotype DX testing; and, (3) the tumor characteristics that may have driven the underutilization of chemotherapy in the high-risk population.