Prognostic Value of Metastatic Axillary Lymph Node Ratio for Chinese Breast Cancer Patients

Huan-Xin Lin,Jia-Yuan Sun,Qin Lin,Todd W. Miller,Qun Li,Xun-Xing Guan,San-Gang Wu,Feng-Yan Li,Zhen-Yu He

doi:10.1371/journal.pone.0061410

Abstract

ObjectiveThe prevalence of breast cancer varies among countries and regions. This retrospective study investigated the prognostic value of the lymph node ratio (LNR) compared with the number of positive lymph nodes (pN) in Chinese breast cancer patients.MethodsThe medical records of female breast cancer patients (N = 2591) were retrospectively evaluated. The association of LNR and TMN staging system were compared with respect to overall, disease-free, and distant metastasis-free survival.ResultsOut of 2591 patients, 2495 underwent modified radical surgery and 96 received breast conserving surgery. All patients had adjuvant chemotherapy following surgery. The median follow up period 66.9 months (range 5–168 months). The 5-year and 10-year overall survival rates were 89.3% and 78.8%, respectively, and 5-year disease-free survival and distant metastasis-free survival rates were 81.6% and 83.5%, respectively. Univariate analysis indicated that in general T, pN, LNR, as well as tumor expression of the estrogen receptor, progesterone receptor, and HER2 were associated with overall, disease-free, and distant metastasis-free survival (all P-values <0.05). Mutlivariate analysis found pN stage and LNR were independent predictors of overall, disease-free, and distant metastasis-free survival (all P-values <0.001). If pN stage and LNR were both included in a multivariate analysis, LNR was still an independent prognostic factor for overall, disease-free, and distant metastasis-free survival (all P-values <0.001).ConclusionOur findings support the use of LNR as a predictor of survival in Chinese patients with breast cancer, and that LNR is superior to pN stage in determining disease prognosis.

Highlights

Metastasis to the axillary lymph nodes is a key indicator of prognosis in breast cancer
Recognizing that axillary lymph node status is the most important predictor of outcomes in breast cancer, the UICC/ American Joint Committee on Cancer (AJCC) TNM staging system for breast cancer emphasized the importance of the absolute number of positive nodes in the N classification for staging breast cancer: pN1 disease indicates 1 to 3 positive axiliary nodes, pN2 denotes 4 to 9 positive nodes, and pN3 is defined as $10 positive nodes [7]
We found that breast cancer patients with lower lymph node ratio (LNR) had longer overall survival, disease-free survival, and distant metastasis-free survival than patients with higher LNR values

Summary

Introduction

Metastasis to the axillary lymph nodes is a key indicator of prognosis in breast cancer. The potential issue of using the absolute number of affected nodes for staging is that the number of lymph nodes examined varies depending upon the surgeon’s views and technique, the patient’s anatomy, and the completeness of the pathological examination [8]. It is not clear the minimal number of nodes that should be examined to establish lymph node metastasis. The implication of the absolute number of positive auxillary lymph on staging is somewhat dependent upon the overall number of nodes examined. Several studies have suggested that the ratio of involved to non-involved nodes may be an alternative, and possibly better, indicator of axillary tumor burden and disease prognosis than pN staging [8,10,11,12,13,14]

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Results

Conclusion