Abstract PO4-05-02: The clinical impact of NOLUS in unresectable/metastatic hormone receptor-positive (HR+)/HER2-negative breast cancer

Abstract

Abstract Background A non-luminal disease score (NOLUS) is pathology-based predictive model to identify PAM50 non-luminal disease within HR+/HER2-negative breast cancer. NOLUS is a new model, therefore, its clinical utility is not sufficiently elucidated. In this study, the clinical impact of NOLUS was investigated in unresectable/metastatic estrogen receptor (ER) positive (ER+)/HER2-negative breast cancer. Patients and Methods The total of 61 patients, who were diagnosed unresectable/metastatic ER+/HER2-negative breast cancer between 2010 and Apr 2023, were included in this study. A NOLUS status was calculated with formula:−0.45∗ER −0.28∗PR +0.27∗Ki67 + 73.02 and diagnosed as NOLUS-positive (≥51.38) and NOLUS-negative (< 51.38) according to the previous reports (Pascual T et al, Front Oncol 2019; 9:303). The relationships between NOLUS status and clinicopathological factors and the prognosis were analyzed. Results Among 61 patients, 10 patients (16.4%) were NOLUS-positive and 51 (83.6%) were NOLOS-negative. NOLUS-positivity was significantly associated with progesterone receptor (PgR)-negativity (p=0.0051) and higher histological grade (0.0234), and had tendency to have shorter recurrence free interval and liver metastasis. NOLUS-positivity was not associated with age, menopausal status and the Ki67. The proportion of the patients whose first line treatment for unresectable/metastatic was endocrine therapy with or without targeted therapy was higher in the NOLUS-negative group. NOLUS-positivity was significantly associated with shorter overall survival (OS; log-rank p=0.0012). Uni- and multivariate analysis, NOLUS-positivity was the poor prognostic factor for OS. Conclusion The prognosis in of the patients with NOLUS-positive unresectable/metastatic HR+/HER2-negative breast cancer was significantly poor. NOLUS is useful to predict the prognosis of these patients. Table. NOLUS and clinicopathological characteristics. NOLUS-positivity was significantly associated with progesterone receptor (PgR)-negativity (p=0.0051) and higher histological grade (0.0234), and had tendency to have shorter recurrence free interval and liver metastasis. NOLUS-positivity was not associated with age, menopausal status and the Ki67. Table. Univariate and multivariate analysis for OS after recurrence NOLUS-positivity was significantly associated with shorter overall survival (OS; log-rank p=0.0012). Uni- and multivariate analysis, NOLUS-positivity was the poor prognostic factor for OS. Citation Format: Wakako Tajiri, Yoshiaki Nakamura, Junji Kawasaki, Yumiko Koi, Sayuri Akiyoshi, Chinami Koga, Eriko Tokunaga. The clinical impact of NOLUS in unresectable/metastatic hormone receptor-positive (HR+)/HER2-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-05-02.