Purpose: To investigate survival of breast cancer patients by 1) age, 2) tumor stage and 3) period of diagnosis, also to determine the contribution of improvements in treatment and opportunistic mammography screening in Austria.
Methods: Survival was calculated overall and by 1) age groups (in years) < 50, 50-64, > 65; 2) stage I, II, IV, unknown 3) for 17,025 patients diagnosed 1988-92, compared with 19,284 patients diagnosed 1993-97. Odds ratios for being diagnosed as stage I in the period 1993-97 compared to 1988-92 were calculated by age group and for all ages.
Results: In the later period (1993-97) age-adjusted mortality rate decreased overall by 3.3% (age: < 50; 8.2%, 50-64; 5.1%, > 65; 1.6%). Overall, stage I cases increased from 46.5% to 51%. Five year relative survival rates improved significantly overall, 6.7% (p < 0.001), and within age groups (age: < 50; 4.5% (p < 0.05), 50-64; 7.2% (p < 0.05) and > 65; 7.3% (p < 0.001). This improvement is confined to patients with stage I tumors in age groups 50-64 (4.1%, p < 0.05) and > 65 (7.2%, p < 0.001) and to patients with stage II in age groups < 50 (7.7%, p < 0.01) and 50-64 (8.3%, p < 0.01). For patients younger than 50, in stage IV, diagnosed 1993-97, survival was significantly poorer (-16.9%, p < 0.05) compared to 1988-92. The odds ratio of being diagnosed as stage I in the later period was 1.19 (95% CI: 1.14, 1.24) for all ages, 1.13 (95% CI: 1.03, 1.24) and for women < 50, 1.3 (95% CI: 1.20, 1.40) 50-64 and 1.15 (95% CI: 1.09, 1.22) > 65 years old.
Conclusion: We conclude that treatment improvements, which are accessible to all patients countrywide due to the compulsory state insurance system, had a major impact on positive trends in mortality and survival. Opportunistic screening should have contributed to some extent beginning in the early nineties.