Clinical outcomes of cancer patients with COVID-19: A systematic review and metaanalysis

Abstract

Background: Patients with coronavirus disease 2019 (COVID-19) and cancer have worse clinical outcomes compared to those without cancer. Primary studies have examined this population, but most had small sample sizes and conflicting results. Prior meta-analyses exclude most US and European data or only examine mortality. The present meta-analysis evaluates the prevalence of several clinical outcomes in cancer patients with COVID-19, including new emerging data from Europe and the US. Methods: A systematic search of PubMED, medRxiv, JMIR and Embase by two independent investigators included peer-reviewed papers and preprints up to July 8, 2020. The primary outcome was mortality. Other outcomes were ICU and non-ICU admission, mild, moderate and severe complications, ARDS, invasive ventilation, stable, and clinically improved rates. Study quality was assessed through the Newcastle-Ottawa scale. Random effects model was used to derive prevalence rates, their 95% confidence intervals (CI) and 95% prediction intervals (PI). Results: Thirty-four studies (N = 4,371) were included in the analysis. The mortality prevalence rate was 25.2% (95% CI: 21.1-29.7;95% PI: 9.8-51.1;I2= 85.4), with 11.9% ICU admissions (95% CI: 9.2-15.4;95% PI: 4.3- 28.9;I2= 77.8) and 25.2% clinically stable (95% CI: 21.1-29.7;95% PI: 9.8-51.1;I2= 85.4). Furthermore, 42.5% developed severe complications (95% CI: 30.4-55.7;95% PI: 8.2- 85.9;I2= 94.3), with 22.7% developing ARDS (95% CI: 15.4-32.2;95% PI: 5.8-58.6;I2= 82.4), and 11.3% needing invasive ventilation (95% CI: 6.7-18.4;95% PI: 2.3-41.1;I2= 79.8). Post-follow up, 49% clinically improved (95% CI: 35.6-62.6;95% PI: 9.8-89.4;I2= 92.5). All outcomes had large I2 , suggesting high levels of heterogeneity among studies, and wide PIs indicating high variability within outcomes. Despite this variability, the mortality rate in cancer patients with COVID-19, even at the lower end of the PI (9.8%), is higher than the 2% mortality rate of the non-cancer with COVID-19 population, but not as high as what other meta-analyses conclude, which is around 25%. Conclusions: Patients with cancer who develop COVID-19 have a higher probability of mortality compared to the general population with COVID-19, but possibly not as high as previous studies have shown. A large proportion of them developed severe complications, but a larger proportion recovered. Prevalence of mortality and other outcomes published in prior meta-analyses did not report prediction intervals, which compromises the clinical utilization of such results.