Objective: To characterize the sites of distant recurrence and clinical outcomes in a cohort of Chinese patients with metastatic triple-negative breast cancer (TNBC).
Methods: One hundred and thirty-four patients with metastatic TNBC treated at Cancer Hospital of CAMS from January 1999 to December 2007 were included in this study. The clinicopathological features and long-term survival of the patients were retrospectively analyzed.
Results: The median age of the patients was 45 years. Most patients (72.7%) had a higher predilection for visceral metastasis and early recurrence within the first two years of follow-up. Six patients (4.5%) presented with stage IV disease, 14 patients were diagnosed with locoregional recurrence after mastectomy, 75 patients with distant metastases, and 45 patients with both locoregional recurrence and distant metastasis. The most common site of first recurrence was the lung, and 62(51.7%)of the patients had more than two sites of metastasis. By July 30, 2009, 75 patients died of breast cancer (56.0%). The median overall survival (OS) was 26.5 months [95% confidence interval (CI), 20.5 - 32.6 months]. The 1-, 3- and 5-year overall survivals (OS) were 80.9%,37.1% and 30.1%, respectively. The median overall survival time of 58 patients with single site of metastasis was 28.5 months, longer than that of patients with more than two sites of metastases. Patients whose initial distant recurrence was bone metastasis only (7 patients) had better prognosis, with a median OS of 84.2 months. The median OS (28.5 vs. 12.6 months, P = 0.0001) differed significantly between patients who received first-line chemotherapy and those who did not. Forty-five of the 96 patients with measurable disease achieved complete/partial response (CR/PR), 39 patients had stable disease (SD), and 12 patients had disease progression (PD). The median OS was 36.1 months in patients with CR/PR, 20.8 months with SD, and 14 months with PD, respectively. The median OS of patients with CR/PR was significantly longer than that of patients with SD/PD (P = 0.0108). Distant metastasis, first-line chemotherapy and clinical response were significantly related with OS by univariate analysis. Furthermore, first-line chemotherapy and the clinical response were demonstrated to be an independent prognostic factor by multivariate analysis.
Conclusions: Recurrence risk and mortality are considerably higher in TNBC patients within the early years of follow-up. TNBC patients have a higher risk of multiple and visceral metastases, and poorer survival, which might attribute to its aggressive clinical behavior and lack of effective regimens. Our findings also suggest that chemotherapy can effectively improve the clinical outcome of those patients.