280P Outcomes of women with early-stage triple-negative breast cancer (TNBC) in connection with age and other socio-demographic factors: A population based cohort study

TNBC is associated with a high risk of local and distant recurrence and is diagnosed at a relatively younger age. There is a paucity of trials focusing on women ≥70 yrs with TNBC. We aimed to determine the outcomes of women with TNBC in relation to age, residence, and marital status independent of known clinical variables. In this retrospective cohort study, women with early-stage operable invasive BC diagnosed during 2010-2018 in the province of Saskatchewan and underwent curative surgery were included. A multivariate Cox proportional hazard model was performed. Various clinical and demographic variables were examined for their prognostic importance of overall survival (OS) for all stages and disease-free survival (DFS) for early-stage TNBC. 485 eligible women were identified. 358 (74%) were <70 yrs old and 127 (26%) were ≥70 yrs old. There were significant differences between the 2 groups in relation to comorbid illness, performance status, secondary cancer, smoking history, and marital status. 86% of women <70 years received (neo)adjuvant chemotherapy vs. 39% of elderly women (p<0.0001). The median follow-up period was 82 months. The median OS of the entire cohort has not been reached. The median OS of women ≥70 yrs was 100 months (95% CI: 56-144), whereas it has not been reached in younger women (p<0.0001). The 5 and 10 year OS of women <70 yrs were 82% and 78%, respectively, compared to 61% and 45% of women ≥70 yrs old (p<0.0001). On multivariate analysis, being single, hazard ratio (HR): 1.46 (1.02-2.08), lack of chemotherapy, 1.57 (1.11-2.23), node-positive TNBC, 2.42 (1.53-3.83), and T3/T4 tumor, 2.77 (1.72-4.46), were significantly correlated with inferior DFS. For OS, age ≥70 years, 1.74 (1.18-2.55), being single, 1.46 (1.02-2.08), comorbid illnesses, 1.61 (1.05-2.46), leukocytosis, 2.28 (1.51-3.44), T3/T4 tumor, 2.77 (1.72-4.46), node-positive TNBC, 2.21 (1.53-3.19), and Grade III tumor, 2.17 (1.32-3.58), correlated with inferior survival. Our study underscores that adjuvant chemotherapy is less frequently used in elderly women. In addition to other known clinical variables, older age and being single were correlated with inferior outcomes.