Trends in the incidence and survival of women with hormone receptor-positive breast cancer from 1990 to 2019: a large population-based analysis

Hormone receptor-positive breast cancer (BC) is the most prevalent subtype of BC and is generally correlated with a favorable prognosis. This study aimed to determine the incidence and survival trends among women diagnosed with hormone receptor-positive BC between 1990 and 2019. Female patients with hormone receptor-positive BC for calendar years 1990-2019 were obtained from the Surveillance, Epidemiology, and End Results (SEER) database and categorized into six diagnostic groups according to the year of diagnosis. Age-adjusted incidence rates (IRs) were calculated using joinpoint regression. We used the Kaplan-Meier method and multivariate Cox regression analyses to determine the association between diagnostic groups, and overall survival (OS) and BC-specific survival (BCSS). The final analysis included 370,729 women, among whom 37,943 (10.2%), 49,266 (13.3%), 55,652 (15.0%), 64,451 (17.4%), 77,127 (20.8%), and 86,290 (23.3%) were diagnosed between 1990 and 1994, 1995-1999, 2000-2004, 2005-2009, 2010-2014, and 2015-2019, respectively. Within the overall cohort, IRs gradually increased from 70 per 100,000 in 1990 to 113 per 100,000 in 2019 (average annual percent change, 1.59%; 95% CI, 1.18-1.99). Multivariate Cox regression analysis revealed that the survival outcomes gradually improved over nearly three decades among hormone receptor-positive BC patients, with a 0.8% and 1.3% decrease in risk for all-cause and BC-specific mortality each year, respectively. Compared to 1990-1994, hormone receptor-positive BC patients diagnosed in 2015-2019 had a 22% lower risk of all-cause death (hazard ratio [HR], 0.78; 95% CI, 0.76-0.81) and a 27% lower risk of BC-specific death (HR, 0.73; 95% CI, 0.70-0.76). The development of treatment strategies within the past three decades, especially endocrine therapy, may contribute to the continuous improvement of clinical outcomes in patients with hormone receptor-positive BC.