Abstract P3-01-07: Comparison of the prognostic value of lymph node ratio versus residual lymph node status in triple negative breast cancer
Authors: De la Cruz-Ku G , Morante Z , Pinto J , Enriquez D , Eyzaguirre E , Saavedra A , Luján M , Luque R , Ramírez M , Araujo J , Fuentes H , Flores C , Moller M , Yakoub D , Neciosup S , Gomez H 
Published: February 2018

Background: Triple negative breast cancer (TNBC) patients with residual disease are characterized for a bad outcome. In these patients nodal involvement after neoadjuvant chemotherapy (NAC) is one of the most important prognostic determinants. In this study we compare two prognostic variables based on nodal status, the lymph node ratio (LNR=#positive nodes/#resected nodes) and residual lymph node status (ypN) in TNBC who received NAC.

Methods: We evaluated a retrospective cohort of TNBC patients with residual disease in the lymph nodes (at least 4 resected nodes) and treated with NAC between 2000-2014 at the Instituto Nacional de Enfermedades Neoplasicas (Lima-Peru). Patients were grouped in three LNR groups (≤0.20, 0.20-0.69 and ≥0.70). Survival differences were calculated by the log rank test. Prognostic factors for progression free survival (PFS) and overall survival (OS) were assessed by the Cox regression analysis.

Results: Overall, 189 were evaluated. Mean age was 48y (range: 26-73) where 53.5% were premenopausal and 16.5% had breast/ovary cancer familial background. A total of 175 pts (92.6%) had clinical T3-T4 tumors and 85.2% had nodal involvement at diagnosis. Indeed, the majority of patients had III CS (94.2%). Regarding to the LNR, 48.2% (n=91), 29.6% (n=56) and 22.2% (n=42) (22.2) had LNR ≤0.20, 0.21-0.69 and ≥0.70, respectively. Distribution of clinical differences was similar between groups, except for the clinical N stage (N2-N3: 15.4%, 46.4%, 52,3%, respectively; p&lt;0.001). The median follow-up was 7 years. Progression risk was higher in patients with LNR ≤0.20 than 0.20-0.69 and ≥0.70 (HR=1.77, 95%CI:1.21-2.59, p=0.003 and HR=2.22, 95%CI:1.47-3.35, respectively, p&lt;0.001). It was similar for the risk of death (HR=1.78, 95%CI: 1.17-2.70, p=0.007 and HR=2.95, 95%CI:1.91-4.56, respectively, p&lt;0.001). LNR groups were associated to progression events (P=0.02) in contrast to ypN groups (P=0.07). In the multivariate analysis, pre-menopausal status, a higher LNR and ypT with non-complete response were prognostic factors of worse DFS. Only a higher LNR has a negative impact on OS (table 1).

Conclusion: LNR was an independent prognostic factor for TNBC in patients with residual disease with better capability than ypN to predict progression events. LNR should be considered in the risk stratification after NAC among these patients.

Table 1. Multivariate Cox Regression AnalysisCharacteristicsDFS  OS   HR95%CIp valueHR95%CIp valuePremenopausal status1.931.37-2.73&lt;0.001nsnsnsLNR 0.20 vs 0.21-0.692.011.36-2.970.0011.781.17-2.700.007LNR 0.20 vs 0.701.751.57-3.74&lt;0.0012.921.88-4.55&lt;0.001ypT complete vs partial1.751.13-2.710.012nsnsnsypT complete vs non-response2.041.20-3.480.009nsnsnsns=not significant

Citation Format: De la Cruz-Ku G, Morante Z, Pinto J, Enriquez D, Eyzaguirre E, Saavedra A, Luján M, Luque R, Ramírez M, Araujo J, Fuentes H, Flores C, Moller M, Yakoub D, Neciosup S, Gomez H. Comparison of the prognostic value of lymph node ratio versus residual lymph node status in triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-01-07.