Background The COVID-19 pandemic hit all over the world and cancer patients are more vulnerable for COVID-19. Mortality rate may increase up to 25% in solid malignancies. In parallel to increased mortality rates among cancer patients, safety concerns regarding cancer treatment has increased over time. However, there were contradictory results for the cancer treatment during pandemic. In this study, we assessed the effect of cancer treatment on the severity of COVID-19. Methods The MEDLINE database was searched on September 01, 2020. Primary endpoints were severe disease and death in the cancer patients treated within the last 30 days before COVID-19 diagnosis. Quality of included studies were assessed by New Castle-Ottawa Scale. Generic inverse variance method was used to calculate odds ratios (ORs) for each outcome. Results Sixteen studies were included for this meta-analysis. Chemotherapy within the last thirty days before COVID-19 diagnosis increased the risk of death in cancer patients after adjusting for confounding variables (OR: 1.85; 95% CI:1.26-2.71). However, severe COVID-19 risk did not increase. Furthermore, targeted therapies, immunotherapy, surgery, and radiotherapy did not increase the severe disease and death risk in cancer patients with COVID-19. Conclusion Chemotherapy increased the risk of death from COVID-19 in cancer patients. However, there was no safety concern for immunotherapy, targeted therapies, surgery, and radiotherapy.
All age groups Risk factor COVID-19