Correlation of Ki-67 proliferative index with oncotype DX recurrence score in hormone receptor-positive, human epidermal growth factor receptor 2-negative early breast cancer with low-burden axillary nodal disease – a review of 137 cases

The use of chemotherapy in breast cancer management has significantly contributed to the decrease in its mortality. Currently, the prognosis is determined by molecular biomarkers, such as oestrogen receptors, and human epidermal growth factor receptor 2. However, the increasing use of advanced molecular technologies, including oncotype DX recurrence score (ODX-RS), has provided the ability to estimate the risk of recurrence. Research has demonstrated that the ODX-RS helps to predict recurrence risk and the potential benefit of chemotherapy in breast cancer. As a result, it can assist clinicians in making decisions regarding using the chemotherapy. The goal of work is to explore the correlation between the ODX-RS and Ki-67 proliferative index (Ki-67-PI).

This study included 137 patients with oestrogen positive, human epidermal growth factor receptor 2-negative early breast cancer, and had non- or early axillary disease.

Patients with low Ki-67-PI were as follows: low ODX-RS in 17%, intermediate ODX-RS in 80%, and high ODX-RS in 2%. In the high Ki-67-PI group: low ODX-RS in 12%, intermediate ODX-RS in 48%, and high ODX-RS in 40%.

In conclusion, the results show no significant correlation between the ODX-RS and Ki-67-PI (r = 0.511, p-value < 0.9).