The risk of COVID-19-related death after breakthrough SARS-CoV-2 infection “remains high” for patients with cancer, according to researchers.
The team also found that patients with a SARS-CoV-2 infection prior to COVID-19 vaccination had an increased risk of death after a breakthrough SARS-CoV-2 infection.
These findings were published in the European Journal of Cancer.
For this study, researchers compared outcomes in cancer patients and health care workers (HCWs) who were vaccinated against COVID-19.
Data from 2391 cancer patients were included. Their median age was 65 years, and 52% were women. Cancer types included hematologic malignancies (22%), breast cancer (19%), lung cancer (12%), and prostate cancer (5%). About half of patients (51%) had metastatic disease, and 3% had received anti-CD20 therapy within 3 months of vaccination.
Ninety-five patients (4%) had a prior SARS-CoV-2 infection and received a single COVID-19 vaccine dose (in compliance with guidelines at the time). Among patients without a prior infection, 63% received 2 vaccine doses, 28% received 1 dose, and 6% received 3 doses.
Among the 2285 HCWs, 11.3% had received 1 vaccine dose, and 88.7% had received 2 or 3 doses.
Results: Breakthrough Infections and Death
The median follow-up was 142 days in the cancer patients and 199 days in the HCWs. The rate of breakthrough SARS-CoV-2 infection was 1.6% in the cancer patients and 1.5% in the HCWs (P =.07).
Among the cancer patients, the incidence of breakthrough infection was 4% in those who received 1 vaccine dose and 0.7% in those who received 2 doses. None of the patients who received 3 doses had a breakthrough infection.
For the cancer patients, independent risk factors for developing COVID-19 after vaccination included being younger than 60 years of age, receiving only 1 vaccine dose, and receiving anti-CD20 therapy in the last 3 months.
Six of the 39 cancer patients with a breakthrough infection died of COVID-19. The cumulative death rate at 50 days post-infection was 17.6%. On the other hand, none of the HCWs died from COVID-19.
The independent risk factors for death in the cancer patients were being male and having a hematologic malignancy, metastatic disease, or a SARS-CoV-2 infection prior to vaccination.
Based on these results, the researchers concluded that 2 or more doses of a COVID-19 vaccine reduce the risk of COVID-19 for cancer patients. However, the risk of death is high, and SARS-CoV-2 infection before vaccination is associated with an increased risk of death.
Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Heudel P, Favier B, Solodky M-L, et al. Survival and risk of COVID-19 after SARS-COV-2 vaccination in a series of 2391 cancer patients. Eur J Cancer. Published online February 9, 2022. doi:10.1016/j.ejca.2022.01.035