"Intermediate-Risk Early Breast Cancer in Young Patients: Tumor Grade Should Be Added to Genetic Testing"

Gangnam Severance and Asan Medical Center Researchers Analyze 1,944 Patients
Grade 3 Tumors in Patients Under 50: Recommend Both Chemotherapy and Targeted Therapy

A Korean study has found that, among patients under the age of 50 for whom genetic testing alone did not provide clear guidance for treatment decisions, tumor grade acts as an independent prognostic factor.

Image representing a breast cancer patient. Photo by Getty Images Korea

On April 23, Gangnam Severance Hospital announced that the breast surgery teams led by Professors Ahn Seong-gwi and Bae Soongjoon, together with Professor Lee Saebyul's team at Asan Medical Center, published the results of a retrospective analysis of 1,944 early breast cancer patients who underwent the Oncotype DX test at the two hospitals between 2011 and 2023 in the International Journal of Surgery.

The study included early breast cancer patients with hormone receptor-positive (HR+), HER2-negative tumors, and no lymph node metastasis. This subtype accounts for 60–70% of all breast cancer cases and is the most common cancer among Korean women. These patients typically undergo the Oncotype DX test—which analyzes 21 genes to predict the risk of distant recurrence within 10 years and the likely benefit of chemotherapy, scoring from 0 to 100 points—to determine whether they should receive adjuvant chemotherapy.

The issue arises for those with a recurrence score in the 11–25 range. This group is classified as 'intermediate risk,' for whom the benefit of chemotherapy remains unclear, making treatment decisions ambiguous. The research team subdivided 802 women aged 50 or younger in this score range according to histologic grade (the speed and pattern of cancer cell growth) and followed their prognoses.

The analysis showed that patients with histologic grade 3 (high grade) tumors had a markedly shorter recurrence-free survival period compared to those with grades 1 or 2. The high-grade group was also associated with poor clinical and pathological features such as lymphovascular invasion, high Ki-67 expression, and a history of chemotherapy.

In multivariate analysis, high histologic grade had a hazard ratio of 6.96 and was confirmed to be an independent factor associated with worse prognosis. This association was particularly pronounced in the group that did not receive chemotherapy.

Among patients older than 50, there was no significant difference in recurrence-free survival according to grade, suggesting that this effect is unique to younger patients.

Research team leading precision studies for early breast cancer treatment. Gangnam Severance Hospital

Professor Ahn, who led the study, said, "We have demonstrated that histologic grade can serve as an additional prognostic factor for patients who receive borderline scores from genetic testing. If an intermediate-risk patient under 50 presents with a grade 3 tumor, more intensive adjuvant systemic treatment—including not only chemotherapy but also targeted therapies such as CDK4/6 inhibitors—should be considered."

This content was produced with the assistance of AI translation services.