Incidence of second primary malignancies in relapsed/refractory B-cell non-Hodgkin's lymphoma patients in England

Treatments for relapsed/refractory (r/r) B-cell non-Hodgkin's lymphoma (NHL) may be associated with an increased risk of second primary malignancies (SPMs). Currently available SPM incidence benchmarks are unreliable due to small sample sizes.

The Cancer Analysis System (CAS), a population-level cancer database in England, was used to identify patients with incident B-cell NHL diagnosed during 2013-2018 with evidence of r/r disease. Incidence rates (IRs) of SPMs after r/r disease diagnosis were calculated per 1000 person-years (PYs) and stratified by age, sex, and SPM type.

We identified 9444 patients with r/r B-cell NHL disease. Of those who were eligible for SPM analysis, nearly 6.0% (470/7807) developed at least one SPM after r/r disease diagnosis (IR: 44.7; 95% confidence interval [CI]: 40.9-48.9). Of note, 205 (2.6%) had a non-melanoma skin cancer (NMSC) SPM. IR of SPMs was the highest for patients with r/r chronic lymphocytic leukemia/small lymphocytic leukemia (80.0) and lowest for diffuse large B-cell lymphoma (DLBCL) (30.9). Patients with DLBCL had the shortest overall survival after r/r disease diagnosis.

This real-world data study suggests that the IR of SPM among patients with r/r B-cell NHL is 44.7 per 1000 PY and that most SPMs diagnosed after r/r disease diagnosis are NMSCs, establishing a basis for the comparison of safety outcomes for new treatments being developed for r/r B-cell NHL.