Endocrine therapy initiation, discontinuation and adherence and breast imaging among 21-gene recurrence score assay-eligible women under age 65.

BACKGROUND: Aside from chemotherapy utilization, limited data are available on the relationship between gene expression profiling (GEP) testing and breast cancer care. We assessed the relationship between GEP testing and additional variables and the outcomes of endocrine therapy initiation, discontinuation and adherence, and breast imaging exams in women under age 65 years. METHODS: Data from five state cancer registries were linked with claims data and GEP results. We assessed variables associated with survivorship care outcomes in an incident cohort of 5014 commercially insured women under age 65 years, newly diagnosed with stage I or II hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2) non-positive breast cancer from 2006 to 2010. RESULTS: Among tested women, those with high Oncotype DX® Breast Recurrence Score® (RS) were significantly less likely to initiate endocrine therapy than women with low RS tumors (OR 0.40 (95% CI 0.20 to 0.81); P = 0.01). Among all test-eligible women, receipt of Oncotype DX testing was associated with a greater likelihood of endocrine therapy initiation (OR 2.48 (95% CI 2.03 to 3.04); P <0.0001). The odds of initiation were also significantly higher for tested vs. untested women among women who did not initiate chemotherapy within six months of diagnosis (OR 3.25 (95% CI 2.53 to 4.16)), with no effect in women who received chemotherapy. Discontinuation and adherence and breast imaging exams were unrelated to tested status or RS. CONCLUSIONS: Lower endocrine therapy initiation rates among women with high RS tumors and among untested women not receiving chemotherapy are concerning, given its established efficacy. Additional research is needed to suggest mechanisms to close this gap.

Real-world economic value of a 21-gene assay in early-stage breast cancer.

OBJECTIVES: Value-based payment reforms shift cost-containment responsibilities to the physician. Although gene expression profiling (GEP) utilizing a 21-gene panel among patients with early-stage, axillary lymph node-negative, hormone receptor-positive, HER2/neu oncogene-negative breast cancer is able to identify a cohort that may achieve excellent outcomes without adjuvant chemotherapy, high up-front costs (list price, $4175) could dissuade usage. STUDY DESIGN: Retrospective review of consecutive patients with breast cancer treated at a single cancer center. METHODS: Chart review of 227 patients 70 years or younger with outpatient costs (ie, drug average sales price, reagent costs, physician charges) during first 6 months of treatment. RESULTS: Of these patients, 68% underwent GEP, with 52%, 43%, and 5% having low, intermediate, and high recurrence risk scores, respectively. Adjuvant chemotherapy was utilized less in genomically profiled cohorts (19% vs 29%; P = .08) and was consistent with recommendations of the recurrence scores. The mean 6-month outpatient costs were $24,955 with adjuvant chemotherapy and $2654 with hormonal therapy. Patients with stage II cancer undergoing GEP received adjuvant chemotherapy at a lower frequency (28.6% vs 86.7%), but patients with stage I cancer who underwent testing were slightly more likely to receive chemotherapy (15.8% vs 14%) because the test identified patients with higher-risk tumors. Universal GEP testing of patients with stage II cancer would have resulted in net savings of $11,494 per patient inclusive of test cost; stage I testing would have increased costs by $4505. Similar trends for grade 2/3 tumors (-$2394) and grade 1 tumors (+$6047) were noted. CONCLUSIONS: Universal GEP testing of women 70 years or younger with stage II or grade 2/3 lymph node-negative breast cancers would result in lower outpatient costs, inclusive of the diagnostic test, within the first 6-month episode of care.