Background: A major goal in Norwegian health politics is that all patients should have equal access to health services irrespective of where they live. Different access to health services may affect prognosis. Breast cancer is the most common type of cancer among Norwegian women. In this article we analyse breast cancer survival by Norwegian county.
Material and methods: Population-based study including all Norwegian women diagnosed with breast cancer between 1985 and 2004. Breast cancer survival was analysed by county using Cox proportional hazards models.
Results: 41,833 women with breast cancer were included in the study. After a median follow-up time of 5.8 years, 16,494 (39.4 %) women died; 9953 (60.3 %) of them of breast cancer. Five-year breast cancer specific survival varied from 74.1 to 80.6 % in the different counties. Age-adjusted analyses that excluded women invited to mammography screening, showed a 20 % difference in breast cancer survival (HR 0.80; 95 %KI 0.72-0.90; p < 0.001) between the counties. For women diagnosed with tumours in stage two, the difference was 45 %. Treatment varied between counties, but the treatment trends were similar in the different counties during the study period.
Interpretation: There is a significant difference in breast cancer survival between Norwegian counties. Possible explanations may be differences in offering of mammography screening, diagnostics and treatment.