Practice Changing Potential of TAILORx: A Retrospective Review of the National Cancer Data Base from 2010 to 2015.

BACKGROUND

Uncertainty regarding chemotherapy benefit among breast cancer patients with intermediate Oncotype Dx recurrence scores (RS; 11-25) led to the TAILORx study. We evaluated chemotherapy use in patients with intermediate RS to determine practice change potential based on the TAILORx results.

METHODS

National Cancer Data Base patients with hormone receptor-positive/human epidermal growth factor receptor 2 (HER2)-negative, N0 breast cancer were identified and were divided into three groups: Group A, ≤ 50 years of age (RS 11-15); Group B, ≤ 50 years of age (RS 16-25); and Group C, > 50 years of age (RS 11-25). Demographic and clinical factors were compared using Chi square tests and Poisson regression models to determine predictors of chemotherapy receipt.

RESULTS

Overall, 37,087 patients met the inclusion criteria, with 6.3% in Group A and 11.7% in Group C having received chemotherapy that may have been avoided based on TAILORx. The majority of Group B (64.7%) did not receive chemotherapy, whereas TAILORx showed potential benefit from treatment. Chemotherapy use decreased over time for all intermediate RS patients. T2 tumors, high grade, and treatment before 2012 increased the likelihood of chemotherapy receipt among both groups. Younger patients with the lower intermediate RS (Group A) were more likely to receive chemotherapy if they had treatment at community or comprehensive centers, whereas moderate grade was also a significant factor to receive chemotherapy in Group B. Significant factors in older patients (Group C) were Black race, estrogen receptor-positive/progesterone receptor-negative, and moderate/high grade.

CONCLUSIONS

The most potential impact of TAILORx findings on practice change is for patients ≤ 50 years of age with RS of 16-25 who did not receive chemotherapy but may benefit. These findings may serve as a baseline for future analysis of practice patterns related to TAILORx.