Mammography screening in Norway: results from the first screening round in four counties and cost-effectiveness of a modeled nationwide screening

Objective: To evaluate whether the results of the first screening round in the Norwegian Breast Cancer Screening Program predict future mortality reduction and to explore the cost-effectiveness of the program. Methods: The results of surrogate measures were calculated and compared with the targets. A cost-effectiveness analysis was performed assuming a nationwide program starting in 1996 with an attendance rate of 80% and a mortality reduction of 30%. Results: The attendance rate was 79.5% and the detection rate was 0.67%. The proportion of invasive tumors smaller than 15 mm was 53.1%, and 21.7% of the patients who underwent axillary surgery had lymphatic metastasis. The C/E ratios were found to be 3750 US dollars (USD) per year of life saved and 86,045 USD per life saved. Conclusion: The results of the first screening round will lead to a mortality reduction of at least 30%. The cost-effectiveness analysis shows that it is possible to run a highly cost-efficient screening program in Norway.