In an article published in Blood Cancer Journal, researchers found that patients with chronic lymphocytic leukemia (CLL) have a 20% higher risk of developing a second primary malignancy (SPM) compared with the general population of the United States.
The investigators compared data from the Surveillance, Epidemiology, and End Results (SEER) database (1973-2015) on the risk of SPMs in surviving patients with CLL with the risks expected in the general population.
Between 1973 and 2015, a total of 38,754 patients were diagnosed with CLL and were followed for nearly 270,000 person-years. In that time, 6487 new SPMs were diagnosed (standardized incidence ratio [SIR], 1.2; 95% CI, 1.17-1.23). Patients with CLL had higher risks for both solid (SIR, 1.15; 95% CI, 1.12-1.18) and hematologic (SIR, 1.61; 95% CI, 1.5-1.73) malignancies compared with the general population.
The researchers also assessed trends in SPMs over time. Patients had the highest risk for SPMs between 2 and 5 months after diagnosis of CLL (SIR, 1.57; 95% CI, 1.41-1.74). Over time, the risk of developing an SPM appeared to be increasing. From 1973 to 1982, the overall risk was 19% higher in patients with CLL compared with the general population (SIR, 1.19; 95% CI, 1.12-1.26). From 2003 to 2015, the risk increased to 36% (SIR, 1.36; 95% CI, 1.3-1.42).
Lastly, the researchers assessed the effects of prior treatments and demographic factors. A multivariate analysis showed higher hazard ratios for developing SPMs among patients with CLL who were male (P <.001), had prior chemotherapy (P <.001), had been diagnosed after 2003 (P <.001), had advanced age (P <.001), and were not white (P =.001).
The authors concluded that “active survivorship plans and long-term surveillance for SPMs are crucial for [improving] outcomes of patients with a history of CLL.”
1. Kumar V, Ailawadhi S, Bojanini L, et al. Trends in the risk of second primary malignancies among survivors of chronic lymphocytic leukemia [published online September 30, 2019]. Blood Cancer J. doi:10.1038/s41408-019-0237-1