We read with the interest the recent paper by Chen et al. who described the clinical progression with COVID-19 in Shanghai, China, 1 which described ninety patients (36.1%) had one or more coexisting chronic medical conditions and one patient had malignant tumor (0.4%). A small amount of literatures have reported that the infection rate of COVID-19 was higher in cancer patients compared with non-cancer patients. In addition, cancer patients are more likely to turn to severe COVID-19 cases than non-cancer patients. [2] [3] [4] In this letter, we describe the demographics, clinical characteristics, and prognosis of cancer patients with COVID-19 infection.
A total of 1380 COVID-19 patients admitted to Renmin Hospital of Wuhan University from January 1, 2020 to March 30, 2020 were screened, and 37 cancer patients with COVID-19 were enrolled. All the enrolled patients were confirmed COVID-19 infected as positive in laboratory tests, including nucleic acid testing or antibody test for SARS-CoV-2. Severe and critical patients are diagnosed according to the New Coronavirus Pneumonia Prevention and Control Program (7th edition). 5 The study was approved by the Institutional Review Board of Renmin Hospital of Wuhan University.
Demographic information and laboratory tests including complete blood count test, liver and kidney function tests, coagulation and immune function tests results were collected upon admission. Continuous variables were shown as median (interquartile range) and percentages were presented for categorical variables. Mann-Whitney U test was used to compare continuous variables. Fisher's exact test was used to compare categorical variables. P < 0.05 was considered to be statistically significant.
In our study, the infection rate of COVID-19 among cancer patients in the single center was estimated to be 2.7% (37 of 1380 patients), which was 6 times higher than that in Wuhan until Mar 30, 2020 (0.45%, 50,006 of 11,081,000). The proportion of severe/critical COVID-19 patients with cancer was 54.1%, which was also significantly higher than that of the general population. 6 As shown in Table 1 , there were 20 male patients (54.1%), and the median age of the patients was 62 years old. According to the previous studies, cancer patients with COVID-19 were much older. 6 , 7 The most common symptoms of onset were fever (75.7%) and cough (56.8%), complicated with dyspnea (32.4%) or fatigue, diarrhea and myalgia.
In addition, cancer patients with COVID-19 were divided into two groups, as mild group, and severe/critical group, according to the severity of COVID-19. Compared with the mild group, patients in the severe/critical group were more likely to have dyspnea (50%). Among the 37 patients, thirteen patients had a history of anti-cancer therapy including surgery, radiotherapy, chemotherapy, targeted therapy, or immunotherapy within one month before hospitalization; six patients in the mild group and seven patients in the severe/critical group respectively. However, with/without the cancer therapy history did not differ significantly between the two groups, suggesting that anti-cancer therapy did not effect on the severity of COVID-19 among these cancer patients. It is noteworthy that the most common cancer was colorectal cancer (29.7%), followed by lung cancer (21.6%) and breast (18.9%). Among the severe/critical patients, there were seven colorectal cancer patients. Previous studies indicated that lung cancer patients were the most common to be infected, which needs more multicenter retrospective studies with a larger sample size to identify. [3] [4] [5] Studies have shown that the prognosis of COVID-19 patients with underlying diseases was poor, while the prognosis of patients with two or more basic diseases would be even worse. 6 In our study, a total of twelve COVID-19-infected cancer patients were complicated with underlying diseases, such as hypertension, diabetes, chronic obstructive pulmonary disease etc., accounting for 32.4%. In the severe/critical group, 8 WBC count, ×10 9 /L 3.5-9. derlying diseases, which was two times higher than that in the mild group, although there was no statistical difference between the two groups. Moreover, five cancer patients died, with a mortality rate of 13.5%, all of which occurred in the severe/critical group. In terms of the results of laboratory tests, we interestingly found that the numbers of neutrophil, NLR, IL-6, LDH and PCT ( Table 2 ) in the severe/critical group were significantly higher than those in the mild group. Studies have shown that increased neutrophils and decreased lymphocytes will increase the risk of severe illness in COVID-19 patients. 6 At the same time, the increase of NLR was also an independent prognostic factor in T1-2 rectal cancer patients. 7 In addition, LDH and PCT were significantly higher in the severe/critical group than that in the mild group. These two indexes were also increased in the general population of patients required ICU admission. 6 Moreover, IL-6 was known to participate in the storm of inflammatory factors caused by COVID-19. The storm could be the main cause of death in infected patients. 8 Therefore, we should pay more attention to the above laboratory indicators in order to identify early and reduce the severe ratio and mortality of cancer patients with COVID-19.
In conclusion, our report originally described and analyzed clinical characteristics and prognosis in cancer patients with COVID-19. Cancer patients had a high infection rate of SARS-CoV-2 and were easy to become severe or critical cases, which should be monitored closely during the COVID-19 epidemic. More multicenter retrospective studies are needed to investigate the comprehensive demographics and risk factors for cancer patients with COVID-19.
All the authors have no conflicts of interest to declare.
This study was supported by the National Natural Science Foundation of China (No. 81903137 ).