Abstract 1959
Background
De novo Stage IV breast cancer (BC) is increasing in premenopausal women. Less is known about current incidence and survival among these women with Stage I-III BC.
Methods
Women ages 20-29 (N = 3,826), 30-39 (N = 34,585), 40-49 (N = 126,552) and 50-59 (N = 172,448) diagnosed with Stage I-III BC from 2000-15 were identified from the US Surveillance, Epidemiology and End Results database. Age-adjusted, annual percentage changes (APC) in incidence and 10-year Kaplan-Meier survival curves were estimated by stage, hormone receptor (HR) status, and grade (low: well/moderately differentiated; high: poorly/undifferentiated) for each age decade.
Results
Stage III BC at presentation decreased with age (20-29 [23.9%], 30-39 [21.9%], 40-49 [16.1%], 50-59 [14.1%]); the opposite pattern was observed for Stage I (23.6%, 28.8%, 42.0%, 48.3%, respectively). HR+ high grade and HR- BCs also decreased with age (20-29 [34.5%, 36.5%], 30-39 [31.1%, 31.6%], 40-49 [23.9%, 21.4%], 50-59 [20.9%, 21.1%]). Among all BC presentations, age-adjusted APC in incidence was higher for women 20-29 (1.6) than those 30-39 (0.3), 40-49 (0.3) or 50-59 (-1.1). Incidence of HR+ low and high-grade BC increased for women <50 with the highest APC (5.7 and 3.8, respectively) for women 20-29; HR- BC incidence decreased for all ages. Among women 20-29, 10-year survival was lowest for those with HR+ high grade BC (Table); for this group, the greatest survival difference between HR+ high grade and HR- BC was for Stage I BC (79.8% vs 89.3%) compared to Stage II (77.2% vs 80.7%) or Stage III (44.9% vs 45.0%). Comparing Stage III BC across age decades, 10-year survival was lowest for women 20-29, notably for HR+ BC.Table: 245P
| Stage | HR Status | Grade | 10-Year Survival % (Standard Error) | |||
|---|---|---|---|---|---|---|
| Age (years) | ||||||
| 20-29 | 30-39 | 40-49 | 50-59 | |||
| Any | + | Low | 81.2 (1.9) | 85.4 (0.5) | 91.1 (0.2) | 89.2 (0.1) |
| + | High | 67.7 (2.0) | 75.3 (0.6) | 80.2 (0.3) | 77.1 (0.3) | |
| - | 73.8 (1.5) | 74.3 (0.5) | 75.1 (0.3) | 74.3 (0.3) | ||
| Stage III | + | Low | 54.2 (5.7) | 62.8 (1.6) | 73.7 (0.7) | 68.3 (0.7) |
| + | High | 44.9 (3.9) | 55.7 (1.3) | 60.1 (0.8) | 54.2 (0.8) | |
| - | 45.0 (3.5) | 49.2 (1.2) | 49.8 (0.8) | 47.5 (0.7) |
Conclusions
Among young women, HR+ BC is increasing in incidence and associated with reduced survival for those 20-29. Understanding the etiologies underlying these trends may inform strategies directed toward improving outcomes for these women.
Clinical trial identification
Legal entity responsible for the study
University of Iowa.
Funding
United States Centers for Disease Control and Prevention (U01DD001035) and the Nealie Belk Stevens Fund for Breast Cancer Research.
Editorial Acknowledgement
Disclosure
All authors have declared no conflicts of interest.