Background: Several studies have shown the association between high neutrophil-to-lymphocyte ratio (NLR) and poor prognosis in various cancer types, including breast cancer. On the other hand, menopausal status, which is an important consideration in breast cancer treatment, has been shown to be associated with changes in NLR levels. The purpose of the present study was to clarify the prognostic significance of preoperative NLR, especially in postmenopausal breast cancer patients.

Patients and methods: Between October 2003 and December 2014, 1868 women underwent surgery without neoadjuvant systemic therapy for primary breast cancer in our department. The optimal cutoff value of preoperative NLR was determined using receiver operating characteristic curve analysis. The patients were divided into two groups based on the NLR cutoff value of 3.34: High NLR (NLR value ≥ 3.34) and Low NLR (NLR value < 3.34). Correlations between clinicopathological characteristics and preoperative NLR were analyzed, and relapse-free survival (RFS) and overall survival (OS) were estimated.

Results: Among the 1868 patients, 286 (15.3%) and 1582 (84.7%) patients were classified into High NLR and Low NLR, respectively. Although the patients in High NLR was younger (p=0.0023), there were no significant correlations between NLR and all other prognostic factors, such as tumor size, lymph node status, and histological grade. High NLR was associated with tendency to shorter RFS (p=0.0583) and shorter OS (p=0.0303). In postmenopausal patients (n=1177), significant correlations were observed between High NLR and shorter RFS and OS (p=0.0002 and p=0.0011). However, NLR was not correlated with RFS and OS in premenopausal patients (n=691). Although the postmenopausal patients with relapsed cancer had higher NLR levels than those without relapse (p=0.0252), NLR levels were not correlated with relapse occurrence in premenopausal patients. Both univariate (p=0.0009) and multivariate (p=0.0015) analyses revealed that High NLR as well as larger tumor size, lymph node metastases, and higher histological grade was significantly associated with relapse in postmenopausal patients. Moreover, in postmenopausal patients, subgroup analysis according to cancer subtype revealed that High NLR was correlated with shorter RFS only in patients with hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer (p=0.0009), in those without adjuvant chemotherapy (p=0.0034) but not in those with adjuvant chemotherapy.

Conclusion: Elevated preoperative NLR is an independent predictor of poor prognosis in postmenopausal but not premenopausal patients with breast cancer. In postmenopausal patients, adjuvant chemotherapy may improve prognosis in patients with HR-positive/HER2-negative breast cancer, especially in those with elevated preoperative NLR.

Citation Format: Ijichi H, Tajiri W, Masuda T, Koga C, Tanaka J, Nakamura Y, Okamoto M, Tokunaga E. Prognostic significance of preoperative neutrophil-to-lymphocyte ratio in postmenopausal breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-24.