ATLANTA—Survival among patients with hairy cell leukemia (HCL) has improved significantly over the past three decades, according to a study reported during the 54th American Society of Hematology Annual Meeting and Exposition.
While therapies for HCL have “changed dramatically,” during this time, large population survival analyses are lacking due to the rarity of the disease, noted Rekha Chandran, MD, of Legacy Health, Vancouver, WA, and colleagues from the Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon.
In 1984, recombinant alpha interferon was approved, followed by development of pentostatin in 1986 and cladribine in 1990, which afforded high response rates and disease control that lasted years, they pointed out. “Monoclonal antibodies, including rituximab—first approved in 1999—have also shown promise; to date, mainly in relapsed HCL.”
Dr. Chandran and colleagues evaluated overall survival and factors associated with mortality trends in patients with HCL in the general U.S. population from 1978 to 2008, using the Surveillance Epidemiology and End Results (SEER-17) database.
A total of 3,360 patients for whom survival status could be determined were included in the analysis, which focused on age, gender, race, and year of diagnosis. Mean age for the entire study population was 58 years (range, 29-86 years).
Age, race, and year of diagnosis were all associated with survival, the researchers found, with risk of death increasing by 5.9% (95% CI 5.2%–6.6%) annually with older age at diagnosis. “After adjusting for age, survival has improved over the study period,” they noted.
Risk of death in an unselected patient of the same age with HCL in the U.S. decreased by 84.9% (95% CI 78.8%–89.3%), with a trend toward a reduction in mortality after 1984. Risk of mortality decreased by 6.5% annually with a later year of diagnosis.
African-American patients had a significantly higher mortality than Caucasians (OR 2.031; 95% CI 1.296–3.181).
“Although there is no way to directly assess the effects of a specific treatment in this analysis, therapeutic advances have likely played a significant role in the dramatic survival improvement in patients with HCL,” Dr. Chandran concluded.