Abstract P6-13-05: Frequency of delivery of systemic chemotherapy in elderly versus younger patients with triple negative breast cancer
Authors: Muhsen S , Dang C , Plitas G , Knezevic A , Stempel M , Patil S , Morrow M , El-Tamer M 
Published: February 2018

Introduction

Chemotherapy (CT) is the standard of care for most triple negative breast cancer (TNBC). Chemotherapy is less commonly recommended in older than younger patients. We aim to explore the frequency of CT delivered in elderly patients when compared to young patients.

Methods

Patients ≤50yrs and ≥70 yrs with stage I-III TNBC defined as ER &lt;10% PR &lt; 10% HER2 IHC &lt; 3+ or FISH &lt; 2.0 and treated at our institution from 2000-2011 were identified from our institutional breast cancer database. Clinicopathologic features were retrieved and co-morbidity indexes (CI) were calculated. Patients were grouped by age and CT use, and features were compared between groups using chi-square tests. Cause of death was reported as dead of disease (DOD) or dead of other causes (DOC) when available; otherwise, it was recorded as dead of unknown causes (DUC). OS survival was estimated using the Kaplan-Meier (KM) methods. Cumulative incidence functions for competing risks were calculated and compared between groups using Gray's test. Competing risks regression was performed for multivariate analysis.

Results

We identified 901 pts with TNBC; 664 (73.7%) were ≤50yrs and 237 (26.3%) were ≥70 yrs. Median followup is 7 yrs (range, 0-16.8yrs).

Younger women diagnosed with TNBC were more likely to have stronger family history of breast cancer (p&lt;.001), to present with palpable masses (p&lt;.001), higher nuclear grade (NG) (p&lt;.001), larger tumors (p=.04), more involved nodes (p=.01), advanced tumor stage (p=.02) and to receive systemic chemotherapy (&lt;.001). Anthracycline-based chemotherapy was administered to 486 (80.3%) in women ≤50yrs and only to 42 (36.5%) in the ≥70 yrs cohort (p&lt;0.001). Chemotherapy data was missing on 2 pts in ≤50 yrs and 4 pts ≥70 for a total cohort of 662 patients ≤50 yrs and 233 pts ≥70 yrs.

The 5 year rates of DOD were similar between both groups at 10.6% (range, 8.3-13.2) for pts ≤50yrs and 10.8% (range, 7.0-15.4) (p=0.52) for the older group; meanwhile, the 5 year OS rates were significantly different between both groups at 87.5% (range, 84.7-90.0) for pts ≤50yrs and 74.3% (range, 68.2-80.0) (p&lt;.001) for the older group since older women die at higher rates from causes other than disease.

CT was given to 115 (49%) patients of the ≥70 yrs cohort with a selection biased by larger tumors (p&lt;.001) and more advanced stages (p&lt;.001). There was no significant difference however, between tumor size (p=0.47) and stage (p=0.98) when comparing the 609 (92%) pts ≤50 yrs and the 115 (49%) of ≥70 yrs patients who received CT.

When categorized based on age and receipt of CT, in the 662 pts ≤ 50 yrs, 609 (92%) and 53 (8%) received CT vs no CT respectively; in the 233 pts ≥70 yrs, 115 (49%) and 118 (50%) received CT vs no CT; the cumulative incidence curves for DOD were not statistically different for the four groups (p=0.85) at 5 years.

Conclusions

In our series, CT was given to 92% of patients ≤ 50 yrs of age. In the elderly pts ≥ 70 yrs of age, CT was limited to 50% of patients, namely those with worse clinicopathologic features.

Citation Format: Muhsen S, Dang C, Plitas G, Knezevic A, Stempel M, Patil S, Morrow M, El-Tamer M. Frequency of delivery of systemic chemotherapy in elderly versus younger patients with 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 P6-13-05.