Breast cancer survival trends in different stages and age groups - a population-based study 1989-2013

Background: During the recent decades, breast cancer survival has gradually improved but there is limited knowledge on the improvement in population-based studies of patients diagnosed with different stages of the disease and in different age groups.Patients and methods: In two Swedish health care regions a total of 42,220 female breast cancer patients below 90years of age were diagnosed between 1989 and 2013. They were treated and followed according to national and regional guidelines and formed a population-based cohort.Results: Using patients diagnosed in 1989-1993 as a reference to the relative risk, 5-year mortality decreased with 49% for patients diagnosed at the end of the observation period (CI 95% 45-58). The mortality tended to decrease for patients with all stages of breast cancer and test for trend resulted in a statistically significant improvement over time in 5-year relative survival in stage III and IV and in 10-year survival in stage I and III. For each operable stage of disease, patients aged below 40years or more than 70years when diagnosed tended to have less favorable survival than patients diagnosed between 40-69years of age. Test for trend resulted in statistically significant improvements over time for patients diagnosed at ages below 40, 40-54 and 54-69, but less marked improvements for patients older than 70 when diagnosed.Conclusions: During the period 1989-2013 the relative risk of 5-year mortality decreased with 49%. Improvements were seen in all age groups but were unevenly distributed between stages and age groups pointing to the need for further improvements for younger and elderly patients.