Results of PONDx, a prospective multicenter study of the Oncotype DX® breast cancer assay: Real-life utilization and decision impact in French clinical practice

Adjuvant chemotherapy shows clear benefits in HER2-positive and triple-negative breast cancer (BC). Its benefits are less universal in BCs expressing hormone receptors. The 21-gene Oncotype DX^® Breast Recurrence Score test was designed for HR+, HER2- early-stage BC before decision on adjuvant chemotherapy. Its validity and utility was demonstrated prospectively across multiple studies. The observational study PONDx characterized the use of Oncotype DX^® Breast in routine practice in France and evaluated its decision impact. Of 882 ER-positive BC patients (67% postmenopausal), most (79%) had N0/Nmic node involvement, grade 2 tumors (68%), tumor size 1-5 cm (88%), and ductal histology (78%). BCs with histopathologically elevated recurrence risk included grade 3: 18%; N1: 21%; Ki67 > 20%: 31%. Recurrence Score results by prognostic category were: <18: 54%, 18-30: 36%; >30: 10%. Compared to recommendations before individual availability of the score, results prompted net absolute reductions in chemotherapy recommendations of 36% (total population), and 29% (grade 3 and/or Ki67 > 20% histologies). Decisions reflected prognostic implications: in the Recurrence Score <18 category, 95% of patients received recommendations of hormonal therapy only, in the >30 category, 97.5% were recommended additional chemotherapy; 95% followed the final recommendations of their physicians. The Recurrence Score provides independent predictive and prognostic information in ER + N0/N1 early BC, including high-risk subgroups. PONDx further characterizes the population where the test is beneficial in real-life use and fits current clinical needs. Oncotype DX^® Breast enables relevant net reductions in chemotherapy use, sparing patients from serious toxicities. Its therapeutic implications are highly accepted by physicians and patients.

Impact of genomic testing and patient-reported outcomes on receipt of adjuvant chemotherapy

Practice guidelines incorporate genomic tumor profiling, using results such as the Oncotype DX Recurrence Score (RS), to refine recurrence risk estimates for the large proportion of breast cancer patients with early-stage, estrogen receptor-positive disease. We sought to understand the impact of receiving genomic recurrence risk estimates on breast cancer patients' well-being and the impact of these patient-reported outcomes on receipt of adjuvant chemotherapy. Participants were 193 women (mean age 57) newly diagnosed with early-stage breast cancer. Women were interviewed before and 2-3 weeks after receiving the RS result between 2011 and 2015. We assessed subsequent receipt of chemotherapy from chart review. After receiving their RS, perceived pros (t = 4.27, P < .001) and cons (t = 8.54, P < .001) of chemotherapy increased from pre-test to post-test, while perceived risk of breast cancer recurrence decreased (t = 2.90, P = .004). Women with high RS tumors were more likely to receive chemotherapy than women with low RS tumors (88 vs. 5 %, OR 0.01, 0.00-0.02, P < .001). Higher distress (OR 2.19, 95 % CI 1.05-4.57, P < .05) and lower perceived cons of chemotherapy (OR 0.50, 95 % CI 0.26-0.97, P < .05) also predicted receipt of chemotherapy. Distressed patients who saw few downsides of chemotherapy received this treatment. Clinicians should consider these factors when discussing chemotherapy with breast cancer patients.

Impact of the 21-Gene Recurrence Score Assay in adjuvant chemotherapy selection for node-negative, hormone receptor-positive breast cancer in the Chinese population

The 21-Gene Recurrence Score Assay has been intensively studied and recommended by major guidelines for treatment decision in early breast cancer. Its impact in adjuvant chemotherapy selection for Chinese population has not been revealed.The prospective part of this study enrolled consecutive node-negative, hormone receptor-positive patients who underwent 21-gene RS testing at Breast Surgery Department of PUMCH (n=134) between May 2012 and August 2013(21-gene RS group). Risk categories were assigned based on the RS and on standard clinicopathologic criteria according to St. Gallen and Adjuvant! Online. The chemotherapy selection and the oncologists' confidence in decision-making before and after RS testing were recorded. The retrospective part of this study compared the chemotherapy decision in the 21-gene RS group and a control group without RS testing (diagnosed between Jan 2011 and Apr 2012,n=170). A total of 304 patients were included in the analysis (134 21-gene RS group, 170 controls). Based on RS, 97 patients were classified as low risk, 29 patients as intermediate risk, and 8 patients as high risk. Tumor grade (P=0.002), PR expression (P<0.001) and Ki-67 index (P<0.001) were significantly different between the 3 risk cohorts.Comparing the St. Gallen guidelines and RS, there was a 41% concordance between risk groups. By using Adjuvant! Online, the correlation between the predicted BCSM and RS was nominal (r=0.10). A total of 29% 21-gene RS group patients changed their treatment decisions after RS testing (P<0.001, 95% CI, 0.18 to 0.49) with 6% (8/134) patients changing to receive chemotherapy besides endocrine therapy and 23% (31/134) changing to reject chemotherapy. After RS testing, more than one half of the oncologists increased their confidence level in treatment recommendation. In the control group, 67.6% (115/170) patients chose chemotherapy plus endocrine therapy. The chemotherapy percentage was much higher than that of 21-gene RS group (30/134, 22%).This is the first study to demonstrate a reduction in the use of adjuvant chemotherapy in women with node-negative hormone receptor-positive breast cancer, based on use of the RS. The RS had an impact on the physicians' treatment decision-making.