The Oncotype DX recurrence score impact on the management of ER-positive, HER2-negative, node-negative breast cancer

Abstract

Introduction: Oncotype DX recurrence score is used to categorize estrogen-receptor-positive, human epidermal growth factor receptor-2 negative, lymph-node negative early breast cancer in high- or low-recurrence risk groups. It has a guiding significance for whether post-operative chemotherapy or only hormonal manipulation is selected as an adjuvant treatment. Aims: Assess the impact of the Oncotype DX recurrence score on adjuvant chemotherapy-related management decision-making in the cases of ER+ve, HER2–ve, LN–ve early breast cancer in our local unit. Material and methods: A cohort of 76 patients with early breast cancer were included, two had bilateral disease. All were operated for estrogen-receptor-positive, human epidermal growth factor receptor-2 negative, lymph-node negative early breast cancer. Tumor grade, Ki67 proliferative index, PREDICT and Oncotype DX recurrence score results were obtained in addition to the offered treatment information for each case. Results: After the primary tumor surgery and an Oncotype DX recurrence score assessment, 18 patients (24%) were eligible for adjuvant chemotherapy; out of them, 10 patients (56%) had a chemotherapy absolute survival benefit of > 15% at 10 years, where 5 patients (30%) had a chemotherapy relative survival benefit of ~ 6.5%, 3 patients (17%) had a chemotherapy relative survival benefit of ~1.6%. In this cohort, 10 patients (13%) had a low Oncotype DX recurrence score; however, they received adjuvant chemotherapy based on other clinico-biological parameters. The other 48 patients (63%) with a low recurrence risk were spared potential adverse events related to the systemic therapy. Based on the menopausal status, every patient had received suitable hormonal manipulation therapy. The data also revealed the absence of a relationship between the Ki67 proliferative index and the Oncotype DX recurrence score (p = 0.06); moreover, the size of the tumor did not correlate with the Oncotype DX recurrence score (p = 0.5). Conclusion: The Oncotype DX recurrence score provides a credible prediction of distant disease recurrence risk in early breast cancer; however, it does not correlate with other prognostic markers, such as the Ki67 proliferative index as well as the tumor size. In this cohort, the use of the Oncotype DX recurrence score led to a 24% rate of treatment recommendations in the direction of adjuvant chemotherapy in addition to anti-hormonal therapy for estrogen-receptor-positive, human epidermal growth factor receptor-2 negative, lymph-node negative early breast cancer.