Racial Variation in the Uptake of Oncotype DX Testing for Early-Stage Breast Cancer

Abstract

Purpose Oncotype DX (ODX) is a tumor gene-profiling test that aids in adjuvant chemotherapy decision-making. ODX has the potential to improve quality of care; however, if not equally accessible across racial groups, disparities in cancer care quality may persist or worsen. We examined racial disparities in ODX testing uptake. Methods We used data from the Carolina Breast Cancer Study, phase III, a longitudinal, population-based study of 2,998 North Carolina women who received a diagnosis of breast cancer between 2008 and 2014. Our primary analysis used modified Poisson regression to determine the association between race and whether ODX testing was ordered among two strata: node-negative and node-positive breast cancer. Results A total of 1,468 women with estrogen receptor–positive, human epidermal growth factor receptor-2–negative, stage I or II breast cancer met inclusion criteria. Black patients had higher-grade and larger tumors, more comorbidities, younger age at diagnosis, and lower socioeconomic status than non-black women. Overall, 42% of women had ODX test results in their pathology reports. Compared with those who did not receive ODX testing, women who received ODX testing tended to be younger and have medium tumor size and grade. Our regression analyses indicated no racial disparities in ODX uptake among node-negative patients. However, racial differences were detected among node-positive patients, with black patients being 46% less likely to receive ODX testing than non-black women (adjusted relative risk, 0.54; 95% CI, 0.35 to 0.84; P = .006). Conclusion We did not find racial disparities in ODX testing for node-negative patients for whom ODX testing is guideline recommended and widely covered by insurers. However, our findings suggest that a newer, non–guideline-concordant application of ODX testing for node-positive breast cancer was accessed less by black women than by non-black women, reflecting more guideline concordant care among black women.

Factors Associated with the Use of Gene Expression Profiles in Estrogen Receptor-Positive Early-Stage Breast Cancer Patients: A Nationwide Study

“…In accordance with previous reports, we observed a higher probability of GEP testing in patients with an intermediate clinical risk profile: smaller tumors of low or intermediate grade without axillary lymph node involvement [11,12,13,14,15]. This finding is in itself not surprising, since in these patients most controversy exists regarding CT benefit.…”

“…We observed a higher incidence of GEP use in younger patients. Several reports endorse this finding [13,14,16], whereas others report an increased use of GEPs in patients between 50 and 69 years of age [11,15]. Since the added value of CT is inversely related with age, the observed preferential GEP use in younger women can possibly be explained by the fact that GEPs are mainly used to seek reassurance in withholding CT in these women in whom guidelines advocate administration of CT [17].…”

“…Previous studies, mainly conducted in a US health care setting, report contradictory results on the association between race, median income or educational status and GEP use. Some observed disparities [13,15,18], whereas others found no differences in GEP uptake [11,12]. In a US health care setting, disparities in GEP uptake between different socioeconomic classes may well be explained by financial inequalities.…”

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

“…The researchers on that study were able to adjust for comorbid illnesses, which they observed were more common among non-white patients(18). …”

Molecular genetic markers of breast cancer

“…2). Их экспрессия определяется среди больных с ER + / PR + , HER-2 -РМЖ без метастазов в лимфатические узлы [21]. Дан-ный набор не должен назначаться больным с HER-2 + или базальноподобным подтипами.…”