An early report pegged the prevalence of cancer among COVID-19 patients at 1%, but authors of a recent meta-analysis found an overall prevalence of 2% and up to 3% depending on the subset of data they reviewed.
However, those findings are limited by the retrospective nature of the studies published to date, according to the authors of the meta-analysis, led by Aakash Desai, MBBS, of the University of Connecticut, Farmington.
Nevertheless, the results do confirm that cancer patients and survivors are an important at-risk population for COVID-19, according to Dr. Desai and colleagues.
“We hope that additional data from China and Italy will provide information on the characteristics of patients with cancer at risk, types of cancer that confer higher risk, and systemic regimens that may increase COVID-19 infection complications,” the authors wrote in JCO Global Oncology.
More than 15 million individuals with cancer and many more cancer survivors are at increased risk of COVID-19 because of compromised immune systems, according to the authors.
Exactly how many individuals with cancer are among the COVID-19 cases remains unclear, though a previous report suggested the prevalence of cancer was 1% (95% confidence interval, 0.61%-1.65%) among COVID-19 patients in China (Lancet Oncol. 2020 Mar;21[3]:335-7). This “seems to be higher” than the 0.29% prevalence of cancer in the overall Chinese population, the investigators noted at the time.
That study revealed 18 cancer patients among 1,590 COVID-19 cases, though it was “hypothesis generating,” according to Dr. Desai and colleagues, who rolled that data into their meta-analysis of 11 reports including 3,661 COVID-19 cases.
Overall, Dr. Desai and colleagues found the pooled prevalence of cancer was 2.0% (95% CI, 2.0%-3.0%) in that population. In a subgroup analysis of five studies with sample sizes of less than 100 COVID-19 patients, the researchers found a “slightly higher” prevalence of 3.0% (95% CI, 1.0%-6.0%).
However, even that data wasn’t robust enough for Dr. Desai and colleagues to make any pronouncements on cancer prevalence. “Overall, current evidence on the association between cancer and COVID-19 remains inconclusive,” they wrote.
Though inconclusive, the findings raise questions about whether treatments or interventions might need to be postponed in certain patients, whether cancer patients and survivors need stronger personal protection, and how to deal with potential delays in cancer clinical trials, according to Dr. Desai and colleagues.
“As the evidence continues to rise, we must strive to answer the unanswered clinical questions,” the authors wrote.
Dr. Desai and colleagues reported no potential conflicts of interest related to the study.
SOURCE: Desai A et al. JCO Glob Oncol. 2020 Apr 6. doi: 10.1200/GO.20.00097.