Abstract P2-16-34: Patterns of survival and efficacy of chemotherapy in elderly patients with triple-negative breast cancer treated in the neoadjuvant setting

Abstract

Abstract Background. Triple negative breast cancer (TNBC) is the most aggressive molecular subtype. It is mostly observed in younger patients, however, substantial proportion of patients are above age of 60. Despite that, this group of patients was not studied and analyzed separately in previous studies. Objectives. To establish efficacy of neoadjuvant chemotherapy in elderly patients with stage II-III TNBC and patterns of progression for this group of patients. Methods. Since 2014 we treated 92 patients with histologically confirmed stage II-III TNBC. Neoadjuvant therapy included 6 cycles of Cisplatin 75mg/m2 day 1 and Paclitaxel 80mg/m2 days 1, 8, 15, every 4 weeks according to local protocol. After neoadjuvant chemotherapy patients proceeded to radical breast surgery with assessing pathological response. Then we analyzed clinical characteristics of patients and their survival according to the pathological response achieved. Results. In our analysis were included 92 patients, 22 of them were elderly patients (above 60). Pathological complete response was achieved in 57,6% of all patients. In the elderly group we observed significantly higher proportion of tumors with advanced stages (N3: 40,9% vs 20,0%, p<0.05, locally advanced: 77,3% vs 51,4%, p<0.05). Although not clinically significant, elderly patients less frequently achieved complete clinical response (28,6% vs 41,4%). Pathologic complete response was achieved in 52,6% of elderly patients and in 71,7% of younger patients (p<0.05). Higher proportion of patients above 60 experienced nephrotoxicity (54,5% vs 17,1%, p<0.05) and peripheral polyneuropathy (22,7% vs 17,1%, p=0.054). In this group of patients only 22,7% completed all 6 cycles as opposed to 65,7% of younger patients (p<0.05). Higher proportion of elderly patients had local recurrence: 45,5% vs 22,9% (p<0.05), visceral metastases: 36,4% vs 17,1% (p<0.05). We observed tendency for this group of patients to have liver and lungs as first sites of metastases (80%), as opposed to younger patients, for whom CNS was the most frequent first metastatic site (50%). To the date of cut-off (June 2019) 17 patients died, all of them due to the progression of the disease (31,8% in elderly group, 14,3% in younger group). Survival outcomes are presented in table below. Table 1. Survival outcomes.SurvivalBelow 60 y.o.Above 60 y.o.Recurrence-free survival<0.053 years73,7%61,9%5 years69,6%51,6%Survival without distant metastases<0.053 years78,9%68,6%5 years74,6%57,2%Overall survival0,0573 years81,8%72,4%5 years77%54,3% Conclusion. In our analysis elderly patients with early and locally advanced TNBC demonstrate decreased response, another safety profile and lower survival rates. Different efficacy could be explained with lower number of cycles of neoadjuvant chemotherapy administered and more advanced stages upon presentation. Different metastatic patterns which we observed in younger and elderly patients should be further studied. Citation Format: Olga Gordeeva, Irina Kolyadina, Lyudmila Zhukova, Inna Ganshina, Dmitry Komov, Andrey Meshcheryakov. Patterns of survival and efficacy of chemotherapy in elderly patients with triple-negative breast cancer treated in the neoadjuvant setting [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-16-34.