Prognosis of COVID-19 in patients with breast cancer A protocol for systematic review and meta-analysis

Background: Coronavirus disease 2019 (COVID-19) has become a pandemic in the world and posed a great threat to people's health. Several meta-analyses have indicated that many comorbidities were associated with increased risk of COVID-19 severity or mortality. The original report also showed that the mortality rate of COVID-19 in breast cancer patients is more dependent on comorbidities than previous radiation therapy or current anti-cancer therapy. However, no meta-analysis has focused on this aspect. This systematic review aims to assess whether breast cancer will increase the severity and mortality of patients infected with COVID-19 and to explore which factors that may affect the severity or mortality rate of breast cancer patients with COVID-19. Methods: We will search the PubMed, Embase, Web of Science, the Cochrane Central Register of Controlled Trials (CENTRAL), China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), and Wanfang database from December 1, 2019 to June 30, 2020. Cohort studies comparing the disease severity and mortality of COVID-19 patients with and without breast cancer will be included. Two independent reviewers will assess the risk of bias of the included cohort studies using the modified Newcastle-Ottawa Scale. We will conduct meta-analyses to calculate the risk ratio (RR) and 95% confidence interval (95% CI) using the random-effects model with the Mantel-Haenszel method. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach will be used to rate the quality of the evidence. Results: The results of this study will be published in a peer-reviewed journal. Conclusion: This study will provide comprehensive evidence for medical staff to adopt effective treatment strategies for breast cancer patients during the COVID-19 pandemic. PROSPERO registration number: CRD42020188208.