Patients with cancer and COVID-19 may need close monitoring and personalized thromboprophylaxis due to an increased risk of venous thromboembolism (VTE), according to researchers.

The researchers found a higher risk of VTE in patients with cancer and COVID-19 who were receiving systemic cancer therapies. Underlying risk factors and demographic factors were also associated with the risk of VTE.

These findings were published in JAMA Oncology.

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The study ( Identifier: NCT04354701) included 4988 patients with cancer and COVID-19 who were hospitalized. A total of 2179 patients (44%) had active cancer, and 1541 (31%) had metastatic cancer.

Most patients (n=3119; 62%) had not received systemic therapy in the 3 months prior to SARS-CoV-2 infection. Of the patients who had received recent systemic treatment, 466 (9%) received endocrine therapy, 332 (7%) received VEGF inhibitors (VEGFis) or tyrosine kinase inhibitors (TKIs), 138 (3%) received immunomodulatory drugs (IMiDs), 262 (5%) received immune checkpoint inhibitors (ICIs), and 1002 (20%) received chemotherapy.

In the overall cohort, the incidence of any thromboembolic event (TEE) was 11%, the incidence of VTE was 7%, and the incidence of arterial thromboembolism (ATE) was 4%.

The incidence of ATE in patients with recent systemic therapy was the same or lower than the incidence in patients who were not recently exposed to systemic therapy. In a log-binomial regression model, the relative risk of ATE was not significantly different between the groups (adjusted risk ratio [aRR], 0.81; 95% CI, 0.56-1.16).

However, the incidence of VTE was higher among patients recently exposed to systemic therapy than among unexposed patients. The incidence of VTE was 6% in the unexposed patients, 7% in those who received endocrine therapy, 8% in IMiD recipients, 10% in VEGFi/TKI recipients, 10% in chemotherapy recipients, and 12% in ICI recipients.

In a log-binomial regression model, recent exposure to systemic therapy was associated with a significantly higher risk of VTE (aRR, 1.33; 95% CI, 1.04-1.69). When the researchers assessed the treatments individually, the association was only significant for ICIs (aRR, 1.45; 95%CI, 1.01-2.07).

Other factors associated with a significantly higher risk of VTE were active or progressing cancer (aRR, 1.43; 95% CI, 1.01-2.03), a history of VTE (aRR, 3.10; 95% CI, 2.38-4.04), and cancers with a high risk of VTE per Khorana score (aRR, 1.42; 95% CI, 1.14-1.75).

There was no significant association between systemic treatment and the risk of TEEs overall, but the risk of TEEs was associated with other factors. Black patients had a significantly higher risk of TEEs than White patients (aRR, 1.24; 95% CI, 1.03-1.50).

Patients with a history of VTE also had a higher risk of TEEs (aRR, 2.33; 95% CI, 1.88-2.89), as did patients who had cancers with a high risk of VTE (aRR, 1.20; 95% CI, 1.02-1.42).

Among patients who had TEEs, 25% died within 30 days, 46% were admitted to the intensive care unit, and 31% required mechanical ventilation.

“[P]atients with cancer and COVID-19 who require hospitalization and have recently received TOIs [treatments of interest] are at a relatively high risk of VTEs; those patients who experience a TEE are at very high risk of death,” the researchers summarized.

“Although not designed to prove causality between systemic therapy exposure and TEEs, our study highlights a potential association, and further investigation with prospective studies and randomized clinical trials is recommended to address risk-mitigation strategies,” the researchers concluded.

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Gulati S, Hsu C-Y, Shah S, et al. Systemic anticancer therapy and thromboembolic outcomes in hospitalized patients with cancer and COVID-19. JAMA Oncol. Published August 17, 2023. doi:10.1001/jamaoncol.2023.2934