Underutilization of gene expression profiling for early-stage breast cancer in California

Abstract

Purpose To describe the utilization of gene expression profiling (GEP) among California breast cancer patients, identify predictors of use of GEP, and evaluate how utilization of GEP influenced treatment of early stage breast cancer. Methods All women diagnosed with hormone receptor positive, node-negative breast cancer reported to the California Cancer Registry between January 2008 and December 2010 were linked to Oncotype DX (ODX) assay results. Results Overall, 26.7% of 23,789 eligible patients underwent the assay during the study period. Women age 65 or older were much less likely than women under age 50 to be tested (15.1% versus 41.4%, p<0.001). Black women were slightly less likely and Asian women slightly more likely than non-Hispanic white women to undergo GEP with the ODX assay (22.2% and 28.9% versus 26.9% respectively, p<0.001). Patients residing in low SES census tracts had the lowest use of the test (8.9%), with the proportion increasing with higher SES category. Women with Medicaid health insurance were less likely than other women to be tested (17.7% versus 27.5%, p<0.001). Receipt of adjuvant chemotherapy (ACT) was associated with the ODX recurrence score, although only 63% of patients whose recurrence scores indicated a high benefit received ACT. Of patients not tested, 15% received ACT. Conclusions Nearly three-fourths of eligible breast cancer patients in California during the 3-year period 2008 through 2010 did not undergo GEP. As a result, it is likely that many women unnecessarily received ACT and suffered associated morbidity. In addition, some high risk women who would have benefited most from ACT were not identified.

Disparities in Systemic Treatment Use in Advanced-stage Non–Small Cell Lung Cancer by Source of Health Insurance

“…Patients may have enrolled in a health plan around the time of diagnosis. Studies have shown that approximately 40% of patients with cancer with Medicaid enrolled at the time of their diagnosis (13,63). These patients, who may have been previously uninsured, present with later-stage disease and have worse survival (45,63).…”

“…Disparities in quality of cancer treatment and cancer outcomes by health insurance status have been documented (13)(14)(15). Studies have shown that patients with Medicaid insurance or no insurance are less likely to receive recommended cancer treatments than patients with private insurance (16)(17)(18).…”

Progress in the clinical detection of heterogeneity in breast cancer

“…The 21-gene expression assay has been widely used to predict tumor heterogeneity in disease recurrence and response to chemotherapy [44][45][46][47]. Various studies have demonstrated that 21-gene recurrence score changed the clinical-pathological adjuvant chemotherapy recommendation [48][49][50][51][52][53].…”

Influence of provider factors and race on uptake of breast cancer gene expression profiling

“…Several studies have reported that only approximately 25% to 50% of eligible patients receive testing, and that testing rates vary depending on nonclinical patient characteristics. In particular, lower adjusted rates of testing have been noted among eligible black patients in a variety of settings, including the National Comprehensive Cancer Network; hospitals in the Atlanta, Georgia metropolitan area; the National Cancer Database; and the California Cancer Registry . However, at least 1 recent population‐based study from Surveillance, Epidemiology, and End Results (SEER) registries failed to find a racial disparity .…”

“…In particular, lower adjusted rates of testing have been noted among eligible black patients in a variety of settings, including the National Comprehensive Cancer Network 7 ; hospitals in the Atlanta, Georgia metropolitan area 8 ; the National Cancer Database 9 ; and the California Cancer Registry. 10 However, at least 1 recent population-based study from Surveillance, Epidemiology, and End Results (SEER) registries failed to find a racial disparity. 11 Institutional characteristics are known drivers of variation in testing rates, 12 and it is possible that observed racial disparities may be explained by the concentration of black patients within hospitals with lower overall rates of testing.…”