Impact of Oncotype DX Recurrence Score on Treatment Decisions: Results of a Prospective Multicenter Study in Turkey

Abstract

Introduction: Breast cancer is the most common malignancy among Turkish women and the rate of early stage disease is increasing. The Oncotype DX® 21-gene assay is predictive of distant recurrence in ER-positive, HER2-negative early breast cancer. We aimed to evaluate the impact of the Recurrence Score® (RS) on treatment decisions and physician perceptions in Turkey. We also studied correlations between RS and routine risk factors.Patients and Methods: Ten academic centers across Turkey participated in this prospective trial. Consecutive breast cancer patients with pT1-3, pN0-N1mic, ER-positive, and HER2-negative tumors were identified at multidisciplinary tumor conferences. The initial treatment decision was recorded before tumor blocks were sent to the central laboratory. Each case was brought back to tumor conference after receiving the RS result. Both pre- and post-RS treatment decisions and physician perceptions were recorded on questionnaire forms. Correlations between RS and classical risk factors were evaluated using univariate and multivariate analyses.Results: Ten centers enrolled a total of 165 patients. The median tumor size was 2 cm. Of 165 patients, 57% had low RS, 35% had intermediate RS, and 8% had high RS, respectively. The overall rate of change in treatment decision was 33%. Initially, chemotherapy followed by hormonal therapy (CT+HT) was recommended to 92 (56%) of all patients, which decreased to 61 (37%) patients post-RS assay (p<0.001). Multivariate analysis indicated that progesterone receptor (PR) and Ki-67 scores were significantly related to RS.Conclusion: Oncotype DX testing may provide meaningful additional information in carefully selected patients.

Correlations Between Oncotype DX Recurrence Score and Classic Risk Factors in Early Breast Cancer: Results of A Prospective Multicenter Study in Turkey

“…Although our results suggest correlation with some pathologic features, the RS result made a significant impact in clinical practice despite rigorous pathologic evaluation at our academic centers, as reported separately (12). The significant predictors in our multivariate analysis included the Ki67 score, which is also considered to be important in predicting luminal subtype.…”

Impact of a 21-Gene Recurrence Score Test on the Choice of Adjuvant Chemotherapy for Hormone Receptor-positive Early-stage Breast Cancer: A Prospective Study

“…We found that the 21-gene RS test reduced chemotherapy use from 78.4% prior to 21-gene RS detection to 33.8% after the 21-gene RS test, corresponding to a reduction of almost 45%. Our study was more aggressive than previous studies in the determination of adjuvant chemotherapy (28,31), as 89.4% of the patients in the 21-gene RS low-risk subgroup belonged to the St. Gallen intermediate-risk group. Indeed, the St. Gallen risk score was shown to be an effective tool for adjuvant chemotherapy decision making (33).…”

Gene Expression Profiling in Breast Cancer and Its Effect on Therapy Selection in Early-Stage Breast Cancer

“…Therefore, studies can be conducted only on a limited group of patients. Studies conducted in Turkey have demonstrated that Oncotype DX has significantly correlated with PR and Ki-67 score of the tumor, and has a significant contribution to determining the therapy selection (44,45). In another study from Turkey, Oncotype DX test was found as cost-effective in patients with early stage breast cancer (46).…”