Risk factors for in-hospital mortality in patients with cancer and COVID-19.

The COVID-19 pandemic is getting worse globally. We read with interest the recent article by Kunyu Yang and colleagues in The Lancet Oncology, which was, to our knowledge, the first to focus on the mortality of COVID-19 in patients with cancer. The authors concluded that receiving chemotherapy within 4 weeks before symptom onset and male sex were independent prognostic factors for in-hospital mortality in patients with cancer and COVID-19.

First, the data in the article showed that 40 (20%) of 205 patients with cancer and COVID-19 had died. However, this finding is insufficient to conclude that patients with cancer and COVID-19 had a higher case-fatality rate than did the general patient population with COVID-19. Additionally, in Wuhan, the mortality rate of inpatients with COVID-19 was 28%, regardless of whether or not they had cancer. Second, we reviewed the cancer history of the 205 patients listed in the article. Based on data availability, we found that 98 (77%) of 127 survivors were at early cancer stage (stage I–II), 121 (82%) of 148 survivors underwent surgery, and 73 (47%) of 156 survivors survived for more than 5 years since their cancer diagnosis, indicating that a substantial proportion of these patients might be clinically cured of their cancer. Therefore, there was a large amount of heterogeneity among the patients with cancer and it would be better to study the association between mortality related to COVID-19 and primary or metastatic thoracic malignancies. Third, the main causes of death for the general patient population with COVID-19 include sepsis, respiratory failure, and acute respiratory distress syndrome. Older age, high Sequential Organ Failure Assessment score, and D-dimer concentration greater than 1 μg/mL are potential risk factors for poor prognosis. Although there were only 40 endpoint events in this article, it is not appropriate to establish the multivariable logistic regression model by use of cancer-related variables, rather than these key risk factors. Because of scarce evidence of the correlation between these factors and mortality in patients with cancer and COVID-19, as well as the small sample size, the conclusion that receiving chemotherapy within 4 weeks before symptom onset is an unfavourable prognostic factor for these patients should be interpreted with caution.

Furthermore, biological sex affects immune responses and COVID-19 outcomes in all populations, not just patients with cancer. Because the expression of angiotensin-converting enzyme 2 (ACE2) is also different in various cancers, an analysis of the relation between case-fatality rate and ACE2 expression in patients with cancer and COVID-19 would be of interest.

Overall, the available evidence might not strongly prove that patients with cancer and COVID-19 have a much higher case-fatality rate than do the general patient population with COVID-19. The decision of whether or not to use chemotherapy should be especially cautious for patients with cancer and COVID-19.