Assessing Cause of Death in Patients with Newly Diagnosed Chronic Lymphocytic Leukemia

Causes of death in patients with newly diagnosed chronic lymphocytic leukemia (CLL) differ according to their CLL-International Prognostic Index (IPI) risk group, according to a study presented as part of the 2020 ASCO Virtual Scientific Program.

Researchers used the Mayo Clinic CLL database to recruit 1,276 patients (median age at diagnosis, 63 years; 69% male) diagnosed with CLL between January 2000 and December 2019 who were evaluated within one year of diagnosis. They assessed incidences of cause-specific death using Gray’s test, and categorized deaths from different causes treated as competing events and excluded any deaths from unknown causes.

Based on CLL-IPI scores, researchers observed that 35% of CLL patients had low-risk disease, 35% had intermediate-risk disease, and 30% had high- and very-high-risk disease, respectively. During a mean follow-up of six years, 286 mortalities occurred. Of those, cause of death was CLL progression in 35% of patients, infection in 6%, second malignancy in 16%, CLL-unrelated in 21%, and unknown in 23%. Results showed that rates of death due to CLL progression were higher (17.3% at five years; 30.3% at 10 years) than the rates due to CLL-related complications (5.7% at five years; 12.9% at 10 years) or due to CLL-unrelated causes (8.6% at five years; 16.9% at 10 years) in the CLL-IPI high- and very-high-risk group, but not the CLL-IPI low- or intermediate-risk group. The investigators found that the CLL-IPI risk group was linked with a higher rate of death due to CLL progression (P<0.001), as well as a higher rate of death due to CLL-related complications (P=0.013) and CLL-unrelated causes (P<0001).

In patients with high- and very-high-risk CLL, improving CLL disease control with novel agents seems justified. In patients with low- and intermediate-risk CLL, there should be increased efforts to reverse immune dysfunction to reduce infections and second malignancies,” the authors concluded.

Wang Y, et al. Cause of Death in Patients with Newly Diagnosed Chronic Lymphocytic Leukemia (CLL) stratified by the CLL-International Prognostic Index (CLL-IPI). Presented at the 2020 ASCO Virtual Scientific Program; May 29-31, 2020.