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

Le résumé fourni par la source

e12634 Background: The number of involved axillary lymph nodes (LNs) found on pathological assessment is regarded as a significant prognostic factor for patients with early-stage breast cancer (EBC). Recent reports have suggested that LNR may be a better surrogate at predicting cancer-specific outcome than the number of involved LN. This retrospective study investigated the prognostic value of LNR, using earlier published cut-off values, before the introduction of SLNB. Methods: A population-based study was performed, using data from UHL Oncology Database, including all women diagnosed with node-positive EBC between 01/01/2001 and 31/12/2010 (N = 553). Records were retrospectively evaluated for clinical, demographic and pathologic data. Majority had axillary node clearance (ANC) (548/553; 99.1%). Patients were divided into 3 LNR risk groups (Low: ≤ 0.20; Intermediate: 0.21 – 0.65; and High: > 0.65). Kaplan-Meier survival analysis was performed. Proportional hazard modelling was undertaken to evaluate whether LNR was associated with overall survival (OS). Results: Median follow-up: 59.8 months (IQR: 37.1 – 88.9). 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 risk group, showed Low risk group had better outcome for OS (p < 0.001). 5- and 10-year OS survival rates were 63% and 58%, respectively. The 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 a prognostic model when combined with age, ER status, PgR status and, HER2 status (p < 0.001). Conclusions: Our findings support the use LNR as a predictor for OS for patients with EBC in Mid-Western Ireland. LNR should be considered as an independent prognostic variable to the current prognostic instruments already in use. In a SLNB and Z0011 era, are we losing potential prognostic information?

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.