Cause of Death Varies by Risk Group in Chronic Lymphocytic Leukemia

The cause of death in patients with newly diagnosed chronic lymphocytic leukemia (CLL) varies by CLL-International Prognostic Index (IPI) risk group, according to research published in Blood Cancer Journal.

Among patients with low- or intermediate-risk disease, the risk of dying from CLL progression was similar to the risk of dying from CLL-related complications, such as infections and second malignancies, or from causes unrelated to CLL.

In contrast, for patients with high- or very high-risk disease, the risk of dying from CLL was 3-fold higher than the risk of dying from CLL-related complications or unrelated causes.

For this study, researchers analyzed 1274 patients from the Mayo Clinic CLL Database who were diagnosed between January 1, 2000, and December 26, 2019. In all, 574 patients received CLL treatment.

Based on the CLL-IPI score, 448 patients (35.2%) had low-risk disease, 442 (34.7%) had intermediate-risk disease, 317 (24.9%) had high-risk disease, and 67 (5.3%) had very high-risk disease.

During a median follow-up of 5 years (range, 0-19 years), there were 286 deaths. The cause of death was attributed to CLL progression in 34.6% of patients, infection in 5.6%, second malignancy in 16.4%, CLL-unrelated causes in 20.6%, and unknown causes in 22.7% of patients.

Patients with high and very-high risk disease had significantly higher rates of death from CLL progression (P <.001), CLL-related complications (P =.013), and CLL-unrelated causes (P <.001) when compared with patients who had low- or intermediate-risk disease.

Among patients with high- or very-high-risk disease, the cumulative incidence of death from CLL progression was higher (17.3% at 5 years; 30.3% at 10 years) than that from CLL-related complications (5.7% at 5 years; 12.9% at 10 years) or CLL-unrelated causes (8.6% at 5 years; 16.9% at 10 years).

For patients with low-risk disease, the cumulative incidence of death from CLL progression (0.3% at 5 years; 2.8% at 10 years) was similar to that from CLL-related complications (2.1% at 5 years; 6.4% at 10 years) or CLL-unrelated causes (0.6% at 5 years; 3.6% at 10 years).

Likewise, for patients with intermediate-risk disease, the cumulative incidence of death from CLL progression (2.0% at 5 years; 10.4% at 10 years) was similar to that from CLL-related complications (2.5% at 5 years; 7.0% at 10 years) or CLL-unrelated causes (3.1% at 5 years; 7.4% at 10 years).

The researchers concluded that “the CLL-IPI risk score has an important role in predicting causes of death in newly diagnosed CLL and has implications in improving patient counseling and advancing clinical practice.”

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Wang Y, Achenbach SJ, Rabe KG, et al. Cause of death in patients with newly diagnosed chronic lymphocytic leukemia (CLL) stratified by the CLL-International Prognostic Index. Blood Cancer J. Published online August 5, 2021. doi:10.1038/s41408-021-00532-1

This article originally appeared on Cancer Therapy Advisor