Long-term Survival Outcomes of Triple-receptor Negative Breast Cancer Survivors Who Are Disease Free at 5 Years and Relationship with Low Hormone Receptor Positivity

Background: We counsel our triple-negative breast cancer (TNBC) patients that the risk of recurrence is highest in the first 5 years after diagnosis. However, there are limited data with extended follow-up on the frequency, characteristics, and predictors of late events.

Methods: We queried the MD Anderson Breast Cancer Management System database to identify patients with stage I-III TNBC who were disease free at 5 years from diagnosis. The Kaplan-Meier method was used to estimate yearly recurrence-free interval (RFI), recurrence-free survival (RFS), and distant relapse-free survival (DRFS), as defined by the STEEP criteria. Cox proportional hazards model was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs).

Results: We identified 873 patients who were disease free at least 5 years from diagnosis with median follow-up of 8.3 years. The 10-year RFI was 97%, RFS 91%, and DRFS 92%; the 15-year RFI was 95%, RFS 83%, and DRFS 84%. On a subset of patients with oestrogen receptor and progesterone receptor percentage recorded, low hormone receptor positivity conferred higher risk of late events on multivariable analysis for RFS only (RFI: HR=1.98, 95% CI=0.70-5.62, P-value=0.200; RFS: HR=1.94, 95% CI=1.05-3.56, P-value=0.034; DRFS: HR=1.72, 95% CI=0.92-3.24, P-value=0.091).

Conclusions: The TNBC survivors who have been disease free for 5 years have a low probability of experiencing recurrence over the subsequent 10 years. Patients with low hormone receptor-positive cancers may have a higher risk of late events as measured by RFS but not by RFI or DRFS.