Doctor and nursing home residents wearing source control

Unvaccinated adults with a recent diagnosis of cancer who had COVID-19 had a sevenfold increased risk of all-cause death than their unvaccinated peers with no SARS-CoV-2 infection, according to a new retrospective cohort study. The findings underscore the vulnerability of people whose immune systems may be weakened by cancer or its treatment, the researchers say.

During the study period of January 2019 to December 2020, over 41,000 adults in a statewide database in Indiana were identified with newly diagnosed cancer, and 6.9% tested positive for SARS-CoV-2. Study participants were in active cancer treatment or in remission. 

Seniors at high risk

Certain cohorts among the unvaccinated patients with cancer, including adults aged 65 years and older, were at highest risk of all-cause death following COVID-19 when compared to other cancer patient populations. Other unvaccinated cancer patients at high risk included persons with two or more comorbid conditions such as hypertension or diabetes, males and rural community dwellers. 

Despite controlling for many other factors that might have contributed to these deaths, exposure to SARS-CoV-2 infection was consistently linked to increased risk, reported Nimish Valvi, PhD, with the Regenstrief Institute in Indianapolis, and Brian E. Dixon, PhD, with Regenstrief and Indiana University.

Other studies have found a lower risk of severe outcomes among cancer patients, but these studies were smaller (in a single cancer center, for example) and their analyses less comprehensive, the authors noted.

Weakened immunity

“This analysis provides additional empirical evidence on the magnitude of risk to patients with cancer whose immune systems are often weakened either by the disease or treatment,” Dixon and colleagues wrote. There is also a “need for continued vigilance against infection given continued waves of infection in the United States, Europe and other nations,” the authors added.

Healthcare providers should take steps to help patients with cancer to stay protected from COVID-19, encouraging them to remain up to date with vaccination and to take other precautions such as social distancing and using source control, Dixon said.  

Full findings were published in JMIR Cancer.

Related articles:

Cancer and dementia patients more at risk from breakthrough COVID infections