Lymph node ratio (LNR) in sentinel lymph node biopsy (SLNB) era: are we losing prognostic information?

• Published in: Clinical breast cancer 2017-04, Vol.17 (2), p.117-126
• Main Authors: Quintyne, K.I, Woulfe, B, Coffey, J.C, Merrigan, A, Gupta, R.K
• Format: Article
• Language: English
• Subjects: Adult; Age Factors; Aged; Axilla; Axillary lymph node dissection (ALND); Breast Neoplasms - mortality; Breast Neoplasms - pathology; Breast Neoplasms - therapy; Disease-Free Survival; Early-stage breast cancer (EBC); Female; Follow-Up Studies; Hematology, Oncology and Palliative Medicine; Humans; Lymph Node Excision - statistics & numerical data; Lymph node ratio (LNR); Lymphatic Metastasis; Middle Aged; Multivariate Analysis; Neoplasm Staging; Obstetrics and Gynecology; Prognosis; Prognostic factor; Retrospective Studies; Sentinel Lymph Node - pathology; Sentinel lymph node biopsy (SLNB); Sentinel Lymph Node Biopsy - statistics & numerical data
• ISSN: 1526-8209; 1938-0666
• DOI: 10.1016/j.clbc.2016.07.011

Abstract Background Number of involved axillary lymph-nodes (LNs) found on pathologically is regarded as a significant prognostic factor in early-stage breast cancer (EBC). Recently, speculation that LNR maybe a better surrogate at predicting cancer-specific outcome than number of involved LN. This study investigated prognostic value of LNR, using pre-determined cut-off values. Methods Data included all women diagnosed with node-positive EBC between 01/01/2001 and 31/12/2010 (N=553). Retrospective evaluation for clinical, demographic and pathologic data performed. Majority had axillary node clearance (ANC) (548/553; 99.1%). Cohort divided by LNR risk-groups (Low: ≤ 0.20; Intermediate: 0.21 - 0.65; and High: > 0.65). Proportional hazard modelling was undertaken to evaluate whether LNR was associated with overall survival (OS). Results Median follow-up: 59.8 months. LNR distribution: Low: 303/553 (54.8%), Intermediate: 160/553 (28.9%) and, High: 90/553 (16.3%). Kaplan-Meier estimates for OS stratified by LNR: Low risk group had better outcome for OS (p < 0.001). Overall 5- and 10-year OS was 63% and 58%, respectively. Number of positive LNs correlated with 10-year OS (66%, 48% and, 48% for patients with N1, N2 and N3 stage respectively; p < 0.001). LNR also correlated with 5-year OS (69%, 48% and, 41% for Low-, Intermediate-, and High-risk groups respectively; p < 0.001). Significantly, LNR on multivariate analysis also formed prognostic model when combined with age, ER status, PgR status and, HER2 status (p < 0.001). Conclusion Findings support LNR as a predictor for OS in EBC. LNR should be considered an independent prognostic variable to current prognostic instruments already in use.