Asymptomatic COVID-19 Rate Much Lower for Patients With Cancer vs General Population

Just 0.6% of patients with cancer tested positive for asymptomatic COVID-19 between March 2020 and September 2020 during pre-procedure screening at an academic cancer center in Philadelphia, according to a study published in the Journal of Cancer Research and Clinical Oncology.

The asymptomatic COVID-19 rate in the study was similar to a previously identified rate of 0.74% among patients in New York City, researchers noted, but noticeably lower than the rate of 17% for the general population reported in a meta-analysis published in 2020.

“Patients with cancer tend to already take measures to try to prevent infection, including physical distancing, avoiding crowds, and avoiding anyone who is sick,” wrote corresponding author Namrata Vijayvergia, MD, and coauthors from Fox Chase Cancer Center. “It is likely that rates of COVID-19 in cancer patients are less than that in the general population because of such increased protective health measures.”

Researchers conducted a retrospective chart review of 4143 patients who underwent COVID-19 testing as part of the pre-procedure screening process at Fox Chase Cancer Center through September 2020. Just 25 patients tested positive for asymptomatic COVID-19, reflecting an incidence of 0.6%.

Among patients with asymptomatic COVID-19, 10 patients never underwent their planned oncologic intervention, including six patients who no longer required the intervention after it was safe to proceed, according to the study. In 50 matched patients who did not test positive for asymptomatic COVID-19, just one patient did not undergo the planned intervention.

Of the 15 patients with asymptomatic COVID-19 who went on to receive their intervention, 11 patients experienced a delay related to COVID-19, the study found. The average delay was 18 days.

“Active screening delayed oncologic care marginally, but the institution of such measures and other precautions (separate treatment rooms and scheduling procedures at the end of the day for infected patients) have ensured safe and prompt cancer care delivery during the pandemic,” the authors wrote. “With these measures and patient education, we maintained the outpatient clinical arena largely free of SARS-CoV-2.”

Reference:
Liu L, Ross NM, Handorf EA, et al. Incidence of asymptomatic COVID-19 positivity in cancer patients and effects on therapy. J Cancer Res Clin Oncol. Published online ahead of print July 29, 2022. doi:10.1007/s00432-022-04231-7