Second Malignant Neoplasms Increase Among Multiple Myeloma Patients
Second malignant neoplasms (SMNs) have increased among younger patients with multiple myeloma, according to research presented at the 59th American Society of Hematology Annual Meeting & Exposition (December 9-12, 2017; Atlanta, GA).
However, researchers did not observe a concomitant significant increase in mortality, and noted a growing reduction in multiple myeloma deaths among patients aged 65 years or younger.
Treatment options for patients with multiple myeloma have steadily increased in the past 20 years. Some research has suggested a correlation between increased risk for SMNs and common multiple myeloma treatments, including immunomodulatory agents such as lenalidomide and autologous hematopoietic cell transplants (AHCT).
Luciano J Costa, MD, PhD, University of Alabama at Birmingham, and colleagues sought to determine the population-level increase in SMNs, and whether increases influenced survival of multiple myeloma patients.
Researchers accessed the Surveillance, Epidemiology and End Results 13 registries to identify cohorts of patients from three distinct time periods: 1995-1999 (n = 2720), 2000-2004 (n = 3246), and 2005-2009 (n = 3867). Patients aged younger than 65 years (median age, 56 years) were included due to their higher likelihood of exposure to lenalidomide and AHCT.
Median follow-up was 198 months in the 1995-1999 cohort; 141 months in the 2000-2004 cohort; and 81 months in the 2005-2009 cohort. Researchers observed a small but significant increase in SMNs, from 4.7% (95% CI, 4-5.6) in the 1995-1999 cohort, to 6% (95% CI, 5.2-6.8) in the 2000-2004 cohort, to 6.3% (95% CI, 5.5-7.1) in the 2005-2009 cohort (P = .0008).
Increases were mostly seen in the context of secondary hematologic malignancies, with a standardized incidence ratio for lymphoma increasing from 0.59 in 1995-1999 to 3.31 in 2005-2009.
In contrast, researchers saw a significant decline in all-cause mortality (69.9% vs 60.4% vs 52.8%; P < .0001). Further, multiple myeloma-related mortality declined from 159.4 persons out of 1000 for the 1995-1999 cohort to 91.7 persons out of 1000 in 2005-2009, and no notable increases in deaths related to SMNs were seen.
“This population study confirms that the evolution of multiple myeloma therapy in the United States in the last 20 years is associated with a small statistically significant increase in SMNs in patients aged 65 years or younger,” researchers concluded. “The study also demonstrates that the mortality from SMN is modest, has not significantly increased over time and is obscured by the robust reduction in mortality from multiple myeloma.”—Cameron Kelsall