Background: The proportion of very young women with breast cancer is high in Asia, ranging between 10% and 25%. Material and methods: Within the multi-institutional Singapore-Malaysia hospital-based breast cancer registry, we compared tumor characteristics, treatment and survival of very young (<35 years; n=210) and older (35-55 years; n=2,152) breast cancer patients diagnosed between 1990 and 2007. Overall survival (OS)was estimated by Kaplan-Meier analysis. Cox regression analysis was used to compute hazard ratios (HR) after splitting follow-up time along the age-axis and calendar-time axis.

Results: Compared to older breast cancer patients, young patients presented with larger tumor (median diameter 25mm vs 30mm respectively: P<0.001), and less estrogen receptor positive (54% vs 46% respectively: P<0.01), and progesterone receptor positive tumors (57% vs 47%: P<0.01). Young women were more likely to receive chemotherapy (70% vs 61%: P<0.01), and less likely to be given hormone therapy (36% vs 57%: P<0.001).

Among those with stage 0 to stage II disease, 5-year OS was 71.3% (95%CI: 61.7%-80.9%) in young patients and 85.6% (95%CI: 83.2%- 88.0%) in older women. After adjustment for stage, tumor profile and treatment, young patients had approximately 50% higher risk of death than their older counterparts (HR:1.46; 95% CI: 1.23-1.73). Ethnicity, tumor size, pathological lymph node staging, loco-regional therapy, and chemotherapy, were significant independent predictors of overall survival among young patients with breast cancer.

Conclusion: Asian women diagnosed at a very young age, present with less favorable tumor characteristics and stage distribution. They have a 50% higher risk of death following their disease, which is independent of their stage at diagnosis, tumor characteristics and treatment.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-11-13.