Patients with hematologic cancers are often heavily immunocompromised due to the malignancy itself and the treatments that they receive. There is emerging evidence that these patients may be more vulnerable to coronavirus disease 2019 (COVID-19) than patients with solid tumors.

In a recently published meta-analysis of outcomes of patients with hematologic cancers and COVID-19, authors incorporated data from 34 adult and 5 pediatric studies that included 3,377 patients from Asia, Europe and North America; 14 of the 34 adult studies comprised hospitalized patients only (n=2,361). The total duration of the studies ranged from 3 to 15 weeks, and COVID-19 was diagnosed using reverse-transcriptase polymerase chain reaction in the majority of cases (71%). The primary outcome of the analysis was the pooled risk of death in all patients and in hospitalized patients. Secondary outcomes included the proportion of hospitalized patients requiring intensive care unit (ICU) admission and ventilation support (mechanical or non-invasive). Subgroup analyses included risk of death stratified by age, treatment status, and malignancy subtype.

The pooled risk of death was 34% in adult patients with hematologic malignancy and COVID-19, and 39% in hospitalized patients. The risk of death in pediatric patients (n=102) was 4%. The pooled risk for ICU admission was 21%, and the risk for mechanical ventilation was 17% versus 16% for non-invasive ventilation. Subgroup analysis showed that patients ≥60 years had a significantly higher risk of death than patients <60 years (47% versus 25%; P<0.00001). There were also differences according to race: non-white patients had a significantly higher risk of death compared with white patients, with a pooled risk ratio (RR) of 2.2 (P=0.003). With respect to treatment status, the RR for death in patients who had received recent systemic anti-cancer therapy (SACT) compared with those who had no treatment was not significant (RR 1.17, P=0.37). The data highlighted some differences between hematologic malignancy subtypes and pooled risk of death: the highest risk was in patients with acquired bone marrow failure syndrome (53%), and the lowest risk was in patients with lymphoma (32%) and chronic lymphocytic leukemia (31%). Of note, the overall risk of death was similar between the three continents (38% in Asia, 35% in Europe, and 31% in North America).

This study is the first meta-analysis to quantify the outcomes of patients with hematologic malignancies and COVID-19, and the authors conclude that adult patients, especially those who are hospitalized and those ≥60 years, have a high risk of death. However, while the risk is substantially higher than the general population, the authors note that the data are comparable with those published for patients with solid tumors. Therefore, patients with hematologic malignancies and COVID-19 should be considered for similarly intensive supportive care measures, where appropriate, especially given that the majority of these patients recover, even if they recently received SACT. Furthermore, treatment of hematologic malignancy should not be routinely withheld due to a fear of higher mortality from COVID-19. While the authors acknowledged several limitations of their study, they highlighted the importance of continued data gathering and meta-analyses to assess trends across specific at-risk patient populations.

Reference

Vijenthira A, et al. Blood 2020 Oct 28 [Online ahead of print]