Increasing Mortality in Korean Patients With Breast Cancer: High Mortality Rate in Elderly Breast Cancer Population Due to Suboptimal Treatment and Other Diseases

Background The incidence of breast cancer in Asia, including Korea, has rapidly increased. Each country has shown different clinical features. This study presents a comprehensive understanding of breast cancer in different age groups in Korea and determines potential measures for improving patient survival. Methods Patients diagnosed with invasive breast cancer stages I to III with available clinicopathologic and follow-up data were included in the study. Kaplan-Meier survival graphs were generated for each group and compared using log-rank test. The hazard ratio for each risk factor was calculated using the Cox regression model and the 95% confidence interval. Results The final cohort included 833 patients with a mean age of 51.3 +/- 11.3 years (range, 22-89 years), and 191 (22.9%) of them were aged >60 years. Patients aged >= 60 years had worse overall survival (OS) and distant disease-free survival than those aged <60 years. Although no difference was observed in the tumor biology, elderly patients showed significant differences in practice patterns: they tended to undergo mastectomy (40.2% vs 62.8%, P<0.001), did not receive the standard chemotherapy (88.4% vs 69.3%, P < 0.001), and had a higher risk of developing second primary cancer or diseases other than breast cancer (1.2% vs 6.8%, P < 0.001), which significantly correlated with poor survival in elderly patients. Conclusion Less-than-the-standard treatment of care or development of a second primary disease resulted in poor prognosis in elderly patients in Korea. A multi-institutional and multinational study is warranted to elucidate the clinical features of breast cancer in Asian patients.