Chronological Improvement in Survival of Patients with Breast Cancer: A Large-Scale, Single-Center Study.

Purpose: This study aimed to chronologically evaluate survival of patients with breast cancer in Korea and investigate the observed changes during the last 20 years. We also sought to determine factors that may influence outcomes and changes in the duration of survival over time.

Methods: We retrospectively analyzed a total of 10,988 patients with breast cancer who were treated at our institution between January 1993 and December 2008. We divided the study period into three periods (P1, 1993-1997; P2, 1998-2002; and P3, 2003-2008). We retrospectively reviewed the collected data from the Asan database, including age at diagnosis, clinical manifestations, pathology report, surgical methods, types of adjuvant treatment modalities, type of recurrence, and follow-up period.

Results: At a median follow-up of 8.2 years, we observed that survival outcomes have improved recently. The 5-year breast cancer-specific survival (BCSS) rate also increased from 82.8% in P1 to 92.6% in P3 ( p <0.001). The survival rate in patients with tumors at each stage increased in similar patterns in all patients, and, remarkably, there was a significant survival improvement in patients with stage III breast cancer (P1 vs. P3: 5-year BCSS, 57.4% vs. 80.0%, p <0.001). The time period was a significant prognostic factor in multivariate analysis (P1 vs. P2: hazard ratio [HR], 0.83, p =0.035; P1 vs. P3: HR, 0.75, p =0.015).

Conclusion: The study results suggest an improvement in breast cancer survival in Korea, which is consistent with the development of treatments and early detection.