Treatment and long-term outcome of breast cancer in very young women: nationwide population-based study

BACKGROUND: The study aimed to assess the correlation between long-term survival and treatment in very young women with breast cancer. METHODS: Data on women with breast cancer were retrieved from the Taiwan Cancer Registry between 2004 and 2014. Patients who did not undergo surgery or who had stage 0 or IV disease were excluded. Survival analysis was conducted. The participants were divided into very young (20–29.9 years), young (30–39.9 years), and adult (40–50.0 years) groups. RESULTS: Among 104 115 women, 24 474 (572 very young, 5565 young, and 18 337 adult) were eligible for the study. Median follow-up was 79.5 (range 24–158) months. The mortality rates in the very young, young, and adult groups were 12.9, 10.0, and 8.2 per cent respectively (P < 0.001). Very young patients had higher histological grade, unfavourable subtype, higher TNM stage, and received more breast-conserving surgery (BCS). Kaplan–Meier survival analysis showed that very young patients had the poorest long-term survival. Very young patients with stage II disease had the worst prognosis. In the multivariable regression model, radiotherapy was associated with decreased local recurrence but not with improved overall, cancer-specific, or disease-free survival for stage II disease in the very young group. Surgery type and chemotherapy were not associated with significant improvement in overall survival. CONCLUSION: Very young patients with stage II disease had poor long-term outcomes. BCS had no detrimental effects on long-term outcomes.