Survival Outcomes for Patients with Metastatic Triple-Negative Breast Cancer: Implications for Clinical Practice and Trial Design

BackgroundClinical experience suggests that many women with triple-negative metastatic breast cancer (MBC) relapse quickly. This has implications for clinical practice and trial design. We evaluated the duration of first-, second-, and third-line chemotherapy as a surrogate for duration of treatment response.Patients and MethodsWe performed a retrospective multicenter chart review of patients with triple-negative MBC receiving palliative chemotherapy. Primary outcome was duration of palliative chemotherapy, and secondary outcome was to identify prognostic variables.ResultsA total of 111 patients were analyzed. Median age at diagnosis was 51 years (range, 26–82 years). Fourteen percent of patients presented with MBC. Twenty-seven percent received neoadjuvant chemotherapy, and 48% received adjuvant chemotherapy. Median distant disease-free interval (DDFI) was 18 months (range, 0–172 months). At presentation of MBC, 68% had visceral and 71% had multiple sites of disease. Median survival with MBC was 13.3 months (range, 0.8–99.8 months). Median duration of first-line palliative therapy was 11.9 weeks (range, 0–73.1 weeks). Eighty-seven patients (78%) went on to receive second-line therapy with a median duration of 9 weeks (range, 0–120.9 weeks), and 55 (49%) received third-line therapy with a median duration of 4 weeks (range, 0–59 weeks). Multivariate analysis revealed that age < 50 years, ALP > 120 U/L, history of previous chemotherapy, DDFI < 12 months, and visceral presentation were all independently associated with a poor prognosis.ConclusionDespite the poorer overall prognosis of patients with triple-negative disease, there remains considerable heterogeneity in individual outcomes. Many women with recurrent triple-negative disease will progress quickly on first-, second-, and third-line palliative treatment. Future clinical trials in this population must take into account their shorter time to progression when determining optimal trial design.