Survival trends in chronic lymphocytic leukemia in the era of oral targeted therapies in the United States: SEER database analyses (1985 to 2017).

Abstract

7524 Background: The survival of chronic lymphocytic leukemia (CLL) patients has progressively improved after the approval of new targeted therapy for first-line treatment and relapsed disease. We performed a corresponding analysis from the U.S. population-based SEER database (1973–2017) to explore the trend of survival and the effect of advanced CLL treatment on overall survival in CLL patients. Methods: Data were extracted from SEER*Stat for all patients 15 years or older with a primary diagnosis of CLL with or without subsequent cancers. A period analysis was performed to estimate the 5- and 10-year relative survival rates for patients diagnosed (dx) during different calendar periods from 1985 to 2017, based on gender and age at time of diagnosis (15–44, 45–54, 55–64, 65–74, 75–84, 85 years or older). A mixture cure model was used to examine the proportion of long-term survivors per gender and age category among CLL patients diagnosed between 1985 and 2015. Cox proportional hazard modeling was used to calculate the hazard ratios (HRs) of death adjusted for gender and age at diagnosis for two cohorts: (a) diagnosed in 2000–2003 and followed to 2012; (b) 2004–2007 and followed to 2015. Results: For males, the 5-year age-adjusted relative survival rate improved progressively from 72.0% (dx 1985-1989) to 88.2% (dx 2010-2014); for females, from 76.8% (dx 1985-1989) to 90.8% (dx 2010-2014). The corresponding 10-year age-adjusted relative survival rates were 47.3% (dx 1985-1989) and 72.5% (dx 2005-2009) for males; and 58.2% (dx 1985-1989) and 78.7% (dx 2005-2009) for females. The table below shows the proportions of long-term survivors for the 1985–2017 cohort as estimated in the mixed cure model. The HRs (95%CI) of death for cohort (b) in comparison to cohort (a) were 0.58 (0.43–0.78), 0.58 (0.48–0.70), 0.57 (0.49–0.67), 0.68 (0.54–0.85); and 0.83 (0.68–1.02) for age categories of 45–54, 55–64, 65–74, 75–84, and 85 years or old. Conclusions: Survival is significantly improved by calendar period among patients diagnosed after 2004 and treated in the era of advanced therapies. Females and younger patients had a higher probability of long term survival. Future studies should consider such covariates as treatment type, disease stage and genetics.[Table: see text]