ABSTRACT
SummaryBackground 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. MethodsWe 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. FindingsA 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{bsim}0.09). The cancer prevalence in COVID-19 patients of Europe (0.22, 95% CI 0.17{bsim}0.28) was higher than that in Asia Pacific (0.04, 95% CI 0.03{bsim}0.06) and North America (0.05, 95% CI 0.04{bsim}0.06). The prevalence of COVID-19-infected cancer patients over 60 years old was 0.10 (95% CI 0.07{bsim}0.14), higher than that of patients equal and less than 60 years old (0.05, 95% CI 0.03{bsim}0.06). The pooled prevalence of severe illness among COVID-19 patients with cancers was 0.35 (95% CI 0.27{bsim}0.43) and the pooled death rate of COVID-19 patients with cancers was 0.18 (95% CI 0.14{bsim}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. InterpretationTo our knowledge, this study is the most comprehensive and up-to-date metaanalysis 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 age. 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 Europeans. Research in context Evidence before this studyCoronavirus disease (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a newly discovered coronavirus, which leads to respiratory illness and can be transmitted from person to person. As the infection has become widespread, concern for the influence of COVID-19 on patients with cancer has grown. Previous studies suggest that patients with a history of active malignancy might be at increased risk for COVID-19, developing COVID-19-related complications and having a poorer prognosis. Until now, however, few studies explored the following two questions: 1) what is the estimated prevalence of cancer patients with COVID-19 infection; and 2) do COVID-19-infected cancer-patients have distinct clinical courses and worse outcomes compared with COVID-19-infected patients without cancers. The latter is based on the former to further explore the characteristics of clinical outcomes of such patients. The clarification of these two questions will greatly help to understand the relationship between COVID-19 and cancer in terms of clinical epidemiology, and thus facilitate the formulation of targeted and relevant public health policies. Added value of this studyTo our knowledge, this systematic review and meta-analysis of 107 studies is the most comprehensive and up-to-date assessing the prevalence of cancer among COVID-19 patients, the incidence of severe illness and mortality rate of COVID-19 patients with cancers. We provided a relatively accurate overall cancer prevalence among the all COVID-19 patients (7%), stratified by geographical continent, country, age, study sample size, and study design type. We also presented the pooled severe illness and mortality rates stratified by continent. European COVID-19-infected cancer patients seemed the most likely to both develop cancer and progress to severe illness and death. Implications of all the available evidenceOur findings have reinforced important considerations of clinical care and emphasized the urgent unmet needs for COVID-19 patients with cancers using the pooled prevalence, incidence of severe illness, and death rates as evidence. Also, after comparing the cancer prevalence, incidence of severe illness, and death rate of COVID-19 patients from different continents, European population may require stronger control measures than the Asia Pacific and North American populations. In the future, as more data will be available, it will be interesting to further investigate the differences of sociodemographic and climcopathological features between COVID-19-infected patients with cancer and without cancer.
