Abstract P3-01-07: Comparison of the prognostic value of lymph node ratio versus residual lymph node status in triple negative breast cancer

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<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<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<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<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<0.0012.921.88-4.55<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.

Abstract P3-10-11: Triple negative breast cancer in young Peruvian patients: 15-years' experience in a public hospital

Background: The incidence of breast cancer (BC) is low in young women and is characterized by a high prevalence of triple-negative tumors, representing a group of high risk. In this work, we describe the clinicopathological and epidemiological features of triple-negative breast cancer (TNBC) in patients aged ≤35 years.

Methods: We reviewed information of TNBC patients diagnosed at ≤35 years old and treated at the Instituto Nacional de Enfermedades Neoplasicas (between 2000 and 2014). The Cox proportional hazard model was used to identify prognostics factors for DFS and OS.

Results: In total, of 243 out 2007 cases (12.11%) were very young TNBC patients. The median follow-up was 9 years. The median age was 32 years (range: 19-35); 14.8% had obesity. A total of 40 (16.5%) patients had a family history of breast-ovary cancer (FHBOC). Regarding to the clinical-pathological characteristics, 59.4% presented T-Stages 3/4; 65.2% had nodal involvement and 7 patients (2.9%) had bilateral BC. Most of patients were diagnosed at Clinical Stage (CS) III (50.8%). The most common histological subtype the was ductal invasive carcinoma (92.1%), followed by medullar (4.5%) and lobulillar (1.7%). A high histological grade was frequent (84.7%), while 71 cases (49%) were diagnosed with vascular permeation and 55 (48.2%) with macrometastasis in lymph nodes. The majority of patients underwent mastectomy (60.2%) compared to lumpectomy (39.8%). Locoregional relapse and distant metastasis were reported in 30.9% and 49.4% of cases, respectively. The most frequent sites of metastases were lung (14.8%) and brain (11.5%). In the multivariate analysis, only N3 stage was associated with a poor outcome in terms of (N0 vs N3, HR=7.89, 95%CI:2.76-22.56, p<0.001). Variables associated with the risk of death were N stage (P<0.001 for N0 vs N3), neoadjuvant chemotherapy (P<0.027), adjuvant chemotherapy (P<0.001), and radiotherapy (P=0.008).

Conclusions: TNBC in very young Peruvian women was characterized by advanced stage at diagnosis. In these patients, nodal involvement was the most important prognostic factor for DFS. It presents distinctive characteristics and poorer outcomes in terms of DFS and OS.

Table 1. Multivariate Cox Regression Analysis.CharacteristicsPFS  OS   HR95% CIp valueHR95% CIp valueN0 vs N11.820.74-4.480.191.510.88-2.590.14N0 vs N22.260.69-7.360.183.031.69-5.46<0.001N0 vs N37.892.76-22.56<0.0013.581.83-7.01<0.001Adjuvant chemotherapynsnsns0.340.20-0.55<0.001Neo-Adjuvant Chemotherapynsnsns0.590.37-0.940.027Radiotherapynsnsns0.560.37-0.860.008ns = not significant

Citation Format: Morante Z, De la Cruz-Ku G, Pinto J, Araujo J, Eyzaguirre E, Saavedra A, Lujan M, Enriquez D, Ramirez M, Fuentes H, Neciosup S, Gomez H. Triple negative breast cancer in young Peruvian patients: 15-years' experience in a public hospital [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 P3-10-11.

Abstract P1-15-02: Benefit of adjuvant chemotherapy in disease-free survival for T1N0 triple negative breast cancer

Background: Although chemotherapy is not recommended in low-risk early breast cancer, triple-negative breast cancers (TNBC) have twice risk of recurrence despite an aggressive treatment. In this study we evaluated the role of chemotherapy in the outcome of T1N0 TNBC patients in terms of disease-free survival (DFS) and overall survival (OS).

Methods: We evaluated a retrospective cohort T1N0 TNBC patients diagnosed between 2000 to 2014 at the Instituto Nacional de Enfermedades Neoplasicas (Lima-Peru). Survival rates differences were assessed by Log-rank test and prognostic factors were identified using the Cox proportional hazards model.

Results: We identified 123 T1N0 TNBC patients. The median age was 51 years (range: 28-85), where 38.5% were premenopausal. Thirty-six (29.3%) were pT1a/b and 87 were pT1c (70.7%). ACT was administered more frequently in pT1c patients (74.7% vs 55.6%; P=0.036). Locoregional relapse and distant metastases rates were 8.3% vs 19.5% and 5.6% vs 16.1% for tumors pT1a/b and pT1c, respectively. The median of follow-up was 8.8 years. Independent prognostic factors were pT stage and treatment with ACT. In relation to pT stage, DFS rates were 97% vs 78% (at 5-years) and 97% vs 70% (at 8-years) for pT1a/b vs pT1c patients, respectively (HR=4.8; 95%CI:1.46-17.0; P=0.015). In the other hand, patients treated with ACT had a better outcome with DFS rates to 5-years of 86% vs 74% and 8-years of 81% vs 65% (HR: 0.41, 95%CI: 0.17-0.97, p=0.043). Our study had not statistical power to evaluate benefit of ACT in pT1a/b patients. In cases with pT1c tumors, treatment with ACT was the only factor associated with a better DFS (HR=0.29, 95%CI: 0.11-0.77, p=0.012). Because the low mortality in our cohort, OS was not evaluable.

Conclusions: Treatment with adjuvant chemotherapy reduces the recurrence risk in 71% among pT1cN0 TNBC.

Citation Format: Morante Z, De la Cruz-Ku G, Pinto J, Araujo J, Fuentes H, Enriquez D, Luque R, Eyzaguirre E, Saavedra A, Luján M, Neciosup S, Gomez H. Benefit of adjuvant chemotherapy in disease-free survival for T1N0 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 P1-15-02.