ABSTRACT
Background Data on the prevalence of cancer in coronavirus disease 2019 (COVID-19)-infected patients and the severe illness incidence and mortality of COVID-19 patients with cancers remains unclear. Methods We systematically searched PubMed, Embase, Cochrane Library, and Web of Science, from database inception to July 15, 2020, for studies of patients with COVID-19 infection that had available comorbidity information on cancer. The primary endpoint was the pooled prevalence of cancer in COVID-19 patients and the secondary endpoint was the outcomes of COVID-19-infected cancer patients with incidence of severe illness and death rate. We calculated the pooled prevalence and corresponding 95% confidence intervals (95% CIs) using a random-effects model, and performed meta-regression analyses to explore heterogeneity. Subgroup analyses were conducted based on continent, country, age, sample size and study design. Findings A total of 107 eligible global studies were included in the systematic review. 90 studies with 94,845 COVID-19 patients in which 4,106 patients with cancer morbidity were included in the meta-analysis for prevalence of cancer morbidity among COVID-19 patients. 21 studies with 70,969 COVID-19 patients in which 3,351 patients with cancer morbidity who had severe illness or death during the studies. The overall prevalence of cancer among the COVID-19 patients was 0.07 (95% CI 0.05~0.09). The cancer prevalence in COVID-19 patients of Europe (0.22, 95% CI 0.17~0.28) was higher than that in Asia Pacific (0.04, 95% CI 0.03~0.06) and North America (0.05, 95% CI 0.04~0.06). The prevalence of COVID-19-infected cancer patients over 60 years old was 0.10 (95% CI 0.07~0.14), higher than that of patients equal and less than 60 years old (0.05, 95% CI 0.03~0.06). The pooled prevalence of severe illness among COVID-19 patients with cancers was 0.35 (95% CI 0.27~0.43) and the pooled death rate of COVID-19 patients with cancers was 0.18 (95% CI 0.14~0.18). The pooled incidence of severe illness of COVID-19 patients with cancers from Asia Pacific, Europe, and North America were 0.38(0.24, 0.52), 0.36(0.17, 0.55), and 0.26(0.20, 0.31), respectively; and the pooled death rate from Asia Pacific, Europe, and North America were 0.17(0.10, 0.24), 0.26(0.13, 0.39), and 0.19(0.13, 0.25), respectively. Interpretation To our knowledge, this study is the most comprehensive and up-to-date meta-analysis assessing the prevalence of cancer among COVID-19 patients, severe illness incidence and mortality rate. The prevalence of cancer varied significantly in geographical continents and ages. The COVID-19 patients with cancer were at-risk for severe illness and a high death rate. The European COVID-19 patients had the highest cancer prevalence among the three continents examined and were also the most likely to progress to severe illness and death. Although the Asia Pacific COVID-19 patients had the lowest cancer prevalence, their severe illness rate was similar to that of European.