Evaluation of Local and Distant Recurrence Patterns in Patients with Triple-Negative Breast Cancer According to Age

Background: Triple-negative breast cancer (TNBC) subtype and young patient age are both associated with an increased risk of local recurrence (LR) and distant recurrence (DR). In young women with TNBC, it is unclear whether subtype or patient age is driving prognosis. Methods: Patients treated for primary TNBC from 1998 to 2011 were identified from the breast surgery database. Clinicopathologic characteristics, treatment, and outcomes were compared between patients <40 and ≥40 years of age at diagnosis. Multivariate models were used to identify factors independently associated with LR and DR. Results: Among 1930 patients with TNBC, 289 (15 %) were <40 and 1641 (85 %) were ≥40 years of age at diagnosis. Younger patients were more likely to present with higher stage disease and more likely to receive mastectomy (p < 0.01), axillary node dissection (p < 0.01), and chemotherapy (p < 0.01). At a median follow-up of 74 (0–201.1) months, there was no difference in LR or disease-free survival (DFS) by age group [5-year LR = 3.9 % (95 % confidence interval (CI) 1.5–6.2) vs. 4.5 % (95 % CI 3.5–5.6) and 5-year DFS = 75.3 % (95 % CI 70.2–80.7) vs. 77.7 % (95 % CI 75.6–79.8), p = 0.94] in patients aged <40 and ≥40 years, respectively. On multivariate analysis, larger tumor size, lymphovascular invasion, and nodal positivity were associated with increased risk of DR. Age and type of surgery were not significantly associated with either outcome. Conclusions: Young age at diagnosis is not an independent risk factor for LR or DR in patients with TNBC.