Mortality from cardiovascular disease (CVD) is increased in patients with non-Hodgkin lymphoma (NHL), according to a retrospective study published in Hematological Oncology.
Use of anthracycline-based chemotherapy and exposure to radiation therapy, both of which have been associated with an increased risk of CVD, are used in the treatment of some patients with NHL. Previous studies have identified an increased risk of CVD in patients with NHL, as well as a higher rate of CVD-related death in this population, although most of these studies focused on CVD morbidity. Hence, gaps remain regarding the relative risk of CVD mortality in patients with specific subtypes of NHL, such as the more aggressive diffuse large B-cell lymphoma (DLBCL) and the more indolent subtypes chronic lymphocytic lymphoma/small lymphocytic lymphoma (CLL/SLL) and follicular lymphoma (FL). In addition, specific risk factors for death from CVD in the patients with these NHL subtypes are unclear.
In this study, 153,983 patients with NHL including those with DLBCL (n=69,329), CLL/SLL (n=48,650) and FL (n=36,004) and corresponding information on race, marital status, cause of death, and prior radiation therapy were identified in the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database for the period between January 2000 and November 2013. Data on CVD-related mortality for the general population was obtained from the Wide‐ranging Online Data for Epidemiologic Research (WONDER) tool from the Centers for Disease Control and Prevention. The primary end point was mortality from CVD.
At a median follow-up of 37 months, the rate of CVD-related mortality was 5.8% in the overall patient cohort, with an age-specific risk that was 14-fold higher than the general population. Within the 3 identified subtypes of NHL, 5.1%, 8.0%, and 4.4% of patients with DLBCL, CLL/SLL, and FL, respectively, died from CVD-related causes. Compared with the general population, the age-specific risks of CVD-related death in patients with CLL/SLL, FL, and DLBCL were 21-fold, 11-fold, and 13-fold higher, respectively.
Following adjustment for confounding factors, specific risk factors for mortality from CVD in patients with all 3 identified subtypes of NHL included older age, male gender, and residing in the southern US states, whereas white race and being married were associated with a lower risk of death from CVD. For patients with FL and DLBCL, another risk factor for CVD-related death was stage IV disease; in patients with these 2 subtypes of NHL, prior radiation therapy was associated with lower mortality from CVD.
Regarding the lower risk of CVD in patients with DLBCL compared with those with CLL/SLL, the study authors speculated that this finding may be related to the lower overall survival of the former group. In addition, they proposed that the association between higher disease stage and increased risk of CVD-related death may be related to an increased likelihood of receiving anthracycline-based chemotherapy for patients with more advanced disease. Furthermore, a decreased likelihood of receiving chemotherapy was offered as a possible explanation for the finding of decreased CVD mortality risk in patients with a history of radiation therapy, although the authors stressed caution in the interpretation of those results.
Some of the limitations of this study identified by the study authors included lack of information regarding administration of chemotherapy or known risk factors for CVD, such as smoking history, diabetes, and hypertension, as well as the possibility that mortality due to CVD is over-represented on death certificates.
“Our data suggest that risk assessment and careful cardiac monitoring are recommended for NHL patients, particularly those with the CLL/SLL subtypes,” the study authors concluded.
Reference Abuamsha H, Kadri AN, Hernandez AV. Cardiovascular mortality among patients with non-Hodgkin lymphoma: differences according to lymphoma subtype [published online March 27, 2019]. Hematol Oncol. doi: 10.1002/hon.2607