The effect of Oncotype DX recurrence score on treatment recommendations for patients with estrogen receptor-positive early stage breast cancer and correlation with estimation of recurrence risk by breast cancer specialists

Abstract

Purpose: The Oncotype DX assay predicts likelihood of distant recurrence and improves patient selection for adjuvant chemotherapy in estrogen receptor-positive (ER-positive) early stage breast cancer. This study has two primary endpoints: to evaluate the impact of Oncotype DX recurrence scores (RS) on chemotherapy recommendations and to compare the estimated recurrence risk predicted by breast oncology specialists to RS.

Methods: One hundred fifty-four patients with ER-positive early stage breast cancer and available RS results were selected. Clinicopathologic data were provided to four surgeons, four medical oncologists, and four pathologists. Participants were asked to estimate recurrence risk category and offer their chemotherapy recommendations initially without and later with knowledge of RS results. The three most important clinicopathologic features guiding their recommendations were requested.

Results: Ninety-five (61.7%), 45 (29.2%), and 14 (9.1%) tumors were low, intermediate, and high risk by RS, respectively. RS significantly correlated with tumor grade, mitotic activity, lymphovascular invasion, hormone receptor, and HER2/neu status. Estimated recurrence risk by participants agreed with RS in 54.2% ± 2.3% of cases. Without and with knowledge of RS, 82.3% ± 1.3% and 69.0% ± 6.9% of patients may be overtreated, respectively (p = 0.0322). Inclusion of RS data resulted in a 24.9% change in treatment recommendations. There was no significant difference in recommendations between groups of participants.

Conclusions: Breast oncology specialists tended to overestimate the risk of tumor recurrence compared with RS. RS provides useful information that improves patient selection for chemotherapy and changes treatment recommendations in approximately 25% of cases.

Figure 1.

Summary of participants' risk estimation and treatment recommendations without and with knowledge of Oncotype DX RS results. (A): Comparison of specialists' estimated recurrence risk to RS. (B): Comparison of specialists' treatment recommendations without and with knowledge of RS. Comparison of percentage of patients recommended chemotherapy without (C) and with (D) knowledge of RS. Abbreviations: A, actual treatment received; O, medical oncologist; P, pathologist; R, actual treatment recommendation; RS, recurrence scores; S, surgeon; *, p < .05, Mann-Whitney test.