How Canadian Oncologists Use Oncotype DX for Treatment of Breast Cancer Patients

Abstract

Background: The literature suggests that medical oncologists differ on how they use the Oncotype DX (ODX) genomic assay for making decisions about systemic therapy in breast cancer patients. Given the emergence of data supporting the use of genomic profiling for the prognosis and predicting benefit of chemotherapy, we surveyed medical oncologists in Canada to assess their usage and perception of the ODX assay. Methods: A 34-item survey was distributed to Canadian medical oncologists via the Canadian Association of Medical Oncologists. Data was collected on physician demographics, ODX usage patterns, and physicians’ perception of the impact clinical and pathologic characteristics make on ODX utilization. Results: Response rate was 20.6% with 47 responses received from 228 survey sent. Forty-five responses were eligible for analysis. Sixty-two percent (28/45) of respondents treated predominantly breast cancer, and 60% (27/45) have been in practice for at least 10 years. The most cited reason for using ODX was to avoid giving patients unnecessary chemotherapy (64%; 29/45). Sixty-seven percent (30/45) deferred making treatment decisions until ODX testing was completed. Factors most strongly impacting ODX utilization included: patient request, medical comorbidities and tumor grade. In clinical scenarios, ODX was more frequently selected for patients aged 40–65 (vs. <40 or >65), grade 2 tumors (vs. grade 1 or 3), and Ki-67 index of 10–20% (vs. <10% or >20%). Conclusions: This survey demonstrated that Canadian medical oncologists are preferentially using ODX to avoid giving patients unnecessary chemotherapy. The utilization of ODX is mainly in patients with intermediate clinical and pathologic features.

Is Oncotype DX testing informative for breast cancers with low ER expression? A retrospective review from a biomarker testing referral center

“…The ODX report also includes an ER (as well as progesterone receptor [PR] and HER2) gene score as an external validation of the ER status of the case under analysis. The ODX RS has been validated in large retrospective and prospective clinical trials [ 16 , 17 ] and has been incorporated as an essential element in adjuvant therapy decision-making for this breast cancer subtype in jurisdictions where it is funded [ 18 , 19 ]. A RS of >25 predicts significant benefit from the addition of chemotherapy to ET for the postmenopausal patient population.…”

Oncotype DX in Breast Cancer Management: Insights and Outcomes From the United Arab Emirates

“…This score helps decide the benefit of chemotherapy for hormone receptor-positive, HER2-negative breast cancer patients [ 20 ]. Oncotype DX has revolutionized personalized breast cancer treatment, enabling clinicians to tailor therapies based on individual genetic profiles, thereby optimizing outcomes and avoiding overtreatment [ 21 ].…”

Impact of the 21-gene expression assay on treatment decisions and clinical outcomes in breast cancer with one to three positive lymph nodes

“…However, several previous studies have found that the 21-gene RS could also predict the survival of N1 patients and have an impact on treatment decisions ( 8 , 10 – 13 ). In Canada, the 21-gene RS has been publicly funded for patients with N0 and ER+/HER2- BC for several years, whereas the coverage of RS testing for N+ patients has been very limited ( 14 ). Given emerging data on the role of RS and the recent discrepant treatment in these patients, this study aimed to clarify the practice patterns and the potential benefit of 21-gene testing in BC patients with ER+/HER2− and one to three LNs.…”