Patients with lymphoproliferative cancers may have a higher risk of breakthrough COVID-19 than patients with myeloproliferative cancers, according to research published in Blood.

Researchers identified patients with hematologic malignancies who developed COVID-19 after full or partial COVID-19 vaccination using data from the EPICOVIDEHA registry ( Identifier: NCT04733729).

There were 113 patients who developed breakthrough COVID-19. About 81% of them (n=91) had lymphoproliferative malignancies. The most common were non-Hodgkin lymphoma (n=36), chronic lymphocytic leukemia (n=28), and multiple myeloma (n=20).   

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About 68% of patients (n=78) received active cancer treatment at the time of COVID-19 diagnosis or within the prior 3 months. Most patients received immunochemotherapy (n=30), targeted therapy (n=21), or conventional chemotherapy (n=13).

Vaccination and Response

In all, 87 patients (77%) were fully vaccinated, and 26 were partially vaccinated. There were 79 patients who received the Pfizer-BioNTech vaccine, 20 who received the Moderna vaccine, 10 who received the Oxford-AstraZeneca vaccine, and 4 who received the Sinovac CoronaVac vaccine.

The median time from the last vaccine dose to COVID-19 diagnosis was 64 days (interquartile range, 33.5-108 days). Among the 87 fully vaccinated patients, COVID-19 was diagnosed more than 2 weeks after the second vaccine dose.

At 2-4 weeks from the last dose, researchers analyzed post-vaccine immunoglobulin G levels against SARS-CoV-2 spike protein in 40 fully vaccinated patients. There were 13 patients (32.5%) with an antibody response and 27 patients (67.5%) who were nonresponders.

Severe Disease and Death

Overall, 79 (60.4%) patients had severe or critical COVID-19. There were 75 patients (66.4%) admitted to the hospital, 16 (21.3%) admitted to an ICU, and 10 (8.8%) who required mechanical ventilation.

At 30 days after COVID-19 diagnosis, 14 patients (12.4%) had died. COVID-19 was the primary or secondary cause of death for all except 1 patient. 

Of the 14 patients who died, 10 (71.4%) had underlying lymphoproliferative malignancies. None of the patients had acute myeloid leukemia, the researchers noted.

There was no significant difference in mortality between partially or fully vaccinated patients — 15.4% and 11.5%, respectively (P =.734) — or between patients achieving a response to vaccination and nonresponders — 13.3% and 15.6%, respectively (P =1).

In a multivariable analysis, age was the only factor that was independently associated with the risk of death (hazard ratio, 1.053; 95% CI, 1.004-1.105; P =.035).

“Our study reports preliminary observations, and the low number of vaccinated patients is the main weakness, for now limiting the possibility to define the real incidence of breakthrough COVID-19 in HM [hematologic malignancies],” the researchers wrote. “Recruitment to this survey continues, and larger numbers of cases will enable us to draw more conclusions in order to develop strategies to prevent severe COVID-19 in this frail population.”


Pagano L, Salmanton-Garcia J, Marchesi F, et al. COVID-19 in vaccinated adult patients with hematological malignancies. Preliminary results from EPICOVIDEHA. Blood. Published online November 8, 2021. doi:10.1182/blood.2021014124

This article originally appeared on Cancer Therapy Advisor