Abstract P2-14-03: Exploring the benefit of adjuvant chemotherapy in elderly women with triple negative breast cancer: 16,062 women age 70 and above
Authors: Crozier Jennifer A , Pezzi Todd A , Hodge Caitlin , Lesnikoski Beth-Ann , Samiian Laila , Shreders Amanda , Hammond William A , Audisio Riccardo A , Pezzi Christopher M 
Published: March 2020

Purpose: The benefit of chemotherapy in older women with breast cancer is not well defined. The aim of this study was to explore the effect of chemotherapy on overall survival (OS) in women ≥ 70 years old with triple-negative breast cancer (TNBC) using the National Cancer Database (NCDB).

Methods: The NCDB was queried for older women (≥ 70 years of age) with surgically treated, AJCC Stage I-III invasive TNBC diagnosed from 2004-2014. Patient demographics, performance status as defined by the Charlson Deyo co-morbidity score, pathologic characteristics, treatment data, and OS were examined. Non-invasive, T1aN0, and any M1 patients were excluded. Multivariate regression analysis and propensity score matching were utilized to minimize bias.

Results: 16,062 elderly women with TNBC met the inclusion criteria, and 7,485 (47.1%) received chemotherapy. Chemotherapy was recommended, but ultimately not administered to 2,659 (16.6%). Chemotherapy was not recommended to 5,732 (35.7%). On multivariate analysis, significantly improved OS was associated with lower co-morbidity score, smaller tumor size, negative lymph node status, infiltrating lobular histology, relatively younger age, and either having received or being recommended to receive chemotherapy (but not administered) [Table 1]. The benefit of chemotherapy was confirmed by conducting a multivariate, propensity score matched analysis of those who received chemotherapy with those who were recommended (but did not receive) chemotherapy (HR 0.70, 0.61 – 0.80) [Table 2]. Within the propensity matched cohort, statistical significance persisted when stratified by nodal status, and the 5-year overall survival of node negative women was 71% vs 74%, and for node positive women was 35% vs 42%.

Conclusion: These data support the consideration of adjuvant chemotherapy in the treatment of women ≥70 years of age with TNBC, especially in those with lymph node involvement. These results can further inform the complex discussion about the benefits and toxicities associated with the administration of chemotherapy in older women with TNBC.

Table 1: Multivariate Cox Regression Overall survival analysis of 16,062 surgically treated women, ≥ 70 years of age, with invasive, triple-negative breast cancer in the National Cancer Database from 2004-2014.p-valueHR95% CILowerUpperComorbidity Score = 010.0001.3181.2121.43520.0001.8251.6212.055Primary Tumor Size ≤5mm6 - 10mm0.7301.0970.6471.86111 - 20mm0.0711.6080.9602.69621 - 50mm0.0002.7281.6324.559&gt;50mm0.0004.0522.4116.807pN0    pN10.0001.6261.4861.779pN20.0002.8622.5483.215pN30.0003.8163.3354.366NX0.0701.3350.9761.824Chemo, Not Received    Chemo Received0.0000.5580.5090.611Chemo Recommended, not received0.0000.7860.7120.868Histology, IDCILC0.0000.6270.4960.794Age, 70 - 74    75 - 800.0031.1591.0511.27780 - 840.0001.3451.2101.49485 - 890.0001.7551.5631.97190+0.0002.5512.2012.956XRT not received    XRT Received0.0000.6170.5720.665Well Differentiated    Moderately Differentiated0.1931.2030.9111.589Poorly Differentiated/Anaplastic0.0051.4771.1271.936

Table 2: Multivariate Cox Regression overall survival analysis of propensity matched sample of surgically treated women, ≥ 70 years of age, with invasive, triple-negative breast cancer in the National Cancer Database from 2004-2014 who received chemotherapy with those who were recommended to received chemotherapy but did not.p-valueHR95% CILowerUpperChemo recommended but not receivedChemo received&lt;0.0050.6980.6100.798pN0pN10.0002.0031.7022.358pN20.0003.0562.4763.771pN30.0003.7532.9564.767Well DifferentiatedModerately Differentiated0.3401.3900.7072.734Poorly Differentiated0.0421.9951.0263.877Advancing Age0.0001.0241.0111.038Comorbidity Score = 010.0001.4001.1991.63420.0011.5181.2001.922Primary Tumor Size≤5mm6-10mm0.9481.0400.3183.41011-20mm0.2571.9490.6156.17821-50mm0.0463.2191.02210.137&gt;50mm0.0055.1911.63716.465

Citation Format: Jennifer A Crozier, Todd A Pezzi, Caitlin Hodge, Beth-Ann Lesnikoski, Laila Samiian, Amanda Shreders, William A Hammond, Riccardo A Audisio, Christopher M Pezzi. Exploring the benefit of adjuvant chemotherapy in elderly women with triple negative breast cancer: 16,062 women age 70 and above [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 P2-14-03.