Breast Cancer Trends in Chile: Incidence and Mortality Rates (2007–2018)

Introduction Breast cancer (BC) is one of the most common cancers in women worldwide and in Chile. Due to the lack of a Chilean national cancer registry, there is partial information on the status of breast cancer in the country. Aims To estimate breast cancer incidence and mortality rates by health care providers and region for Chilean women. Methods We used two public anonymized databases provided by the Department of Health Statistics and Information of the Ministry of Health: the national death and hospital discharges datasets. For calculations of incidence and mortality rates, we selected all patients whose primary diagnosis was breast cancer, according to the CDI-10 diagnostic code. Results We considered a cohort of 58,254 and 16,615 BC hospital discharges and deaths for the period 2007–2018. The new cases of BC increased by 43.6%, from 3,785 in 2007 to 5,435 in 2018. Total BC deaths increased by 33.6% from 1,158 to 1,547 during the same time period. Age–adjusted incidence rates were stable over time, with an average rate of 44.0 and a standard deviation of 2.2 during the study period. There were considerable differences in age–adjusted incidence rates among regions, with no clear geographical trend. Women affiliated to a private provider (ISAPRE) have an average age adjusted incidence rate of 60.6 compared to 38.8 for women affiliated with the public provider (FONASA). Age–adjusted mortality rates did not change significantly during the study period, with an average of 10.5 and a standard deviation of 0.4. Discussion This study shows important differences in incidence rates between private and publicly insured women, with no significant differences in mortality rates. This result suggests potential inequalities in breast cancer healthcare outcomes in Chilean women, that should be studied in greater depth. Additionally, differences in breast cancer incidence found in this study compared to incidences reported from other estimations reinforce the need of a national cancer registry that should lead to more accurate indicators regarding breast cancer magnitude in Chile.