We report here a cohort of 56 cancer patients with laboratory confirmed SARS-CoV–2 infection. In our study, the infection rate of COVID–19 among cancer patients in the single center is estimated to be 3.6% (79 of 2143 patients), which is significantly higher compared with the general population in previous research( 2.3% [1023 deaths among 44 672]). This result is also in accordance with other studies that reported high rates of infection due to impaired immune function caused by by the disease itself or the treatment. Approximately 21%(12 of 56 patients) of all hospital patients with cancer dying during their hospital stay. The mortality rate in cancer patients with COVID–19 in our cohort is high. In a cohort of 37 cancer patients with SARS-CoV–2 infection from a single hospital in China, 5 patients patients had died, with a mortality rate of 13.5%. 3 (25%) of 12 cancer patients with SARS-Cov–2 infection were also reported to have died at a Tertiary Care Hospital in Wuhan, China.
Compared with the overall population, the average age of all cancer patients with COVID–19 infections is higher(64 vs 49). We observe that cancer non-survivors are no older than cancer survivors. In our cohort, gastrointestinal cancers (23%) are the most commonly encountered tumors. This did not concur with previous studies, in which lung cancer patients were the most common to be infected[19, 20]. However, oneclinical studyhave reported the samefound. Therefor, more multicenter retrospective studies with a larger sample size is required. The clinical symptoms of onset included fever, cough, dyspnea and fatigue. Sputum and broad use of antibiotics were more frequently noted in non-cancer survivors.
Of all included cancer non-survivors, 6 (50%) had ARDS and 10 (83%) required mechanical ventilation. It also supports the notion that patients with cancer were observed to have a higher risk of severe events caused by the SARS-CoV–2. Notably, leukemia and lymphoma patients have a higher probability of severe complications compared with patients with other cancer types. Laboratory tests showed severe lymphopenia, increased levels of lactate dehydrogenase and NT-proBNP in cancer non-survivors compared to cancer survivors. Apart from this, in comparison with the surviving group, non surviving group deteriorated more rapidly (4.5 vs 14.5 days).
With more cancer non-survivors have a history of receiving anticancer treatment within one mouth, suggesting that anti-cancer therapy may have an adverse effects on the severity of COVID–19 among cancer patients. It is noteworthy, however, that significantly more non-survival patients with hematologic malignancies, such as leukemia or lymphoma, in which severe complications such as anemia, thrombocytopenia and profound derangements in coagulation function are inherently more expected. Whether to continue cancer therapy or to delay it is still in controversial, as the risk of cancer progression after stopping cancer therapy remains unknown[3, 8]. In general, treatment delay is not recommended in patients who are at high risk of disease progression or patients who are receiving curative cancer therapy despite the potential risk of COVID–19 infection during anticancer therapy. Thus, more future studies are warranted before any recommendation can be generalized. Intravenous glucocorticoids and immunoglobulin were commonly used in cancer patients with severe SARS-CoV–2, however, with no statistical difference between the two groups,their efficacy remains controversial and their use to treat SARS-CoV–2 infection is also controversial.
It is well known that COVID–19 is associated with cytokine storm and elevated levels of inflammatory markers (interleukin–6, IL–6). Cytokine release syndrome (CRS) is considered to be the main cause of ARDS in patients infected with SARS-CoV. Similarly, cytokines responses are recognized as important roles in cancer development, progression and metastasis, and are therefore potential prognostic factors[24, 25]. In our study, the degree of cytokine elevation correlates well with adverse clinical outcomes in cancer patients with COVID–19. Moreover, cancer non-survivors had higher concentrations of IL–2R, IL6, and IL10 than those survivors suggesting that the cytokine storm was associated with disease severity. Elevated serum IL–2R, IL6, and IL10 are associated with an unfavorable prognosis and a higher risk of mortality[26, 27]. Therefore, nowadays, the application of drugs that block IL–6 including tocilizumab and sarilumab to treat critically ill patients with CODIV–19 is an active area for research[28, 29].
To our knowledge, this is the first study to pay attention to the follow-up of recovered cancer patients with COVID–19. 3(6.8%) cancer patients with COVID–19 who met criteria for hospital discharge as a previously described method (asymptomatic, normal radiological images and 2 consecutive negative RT-PCR test results) had positive RT-PCR test results(throat swabs) 7 days later. This finding suggests that individual recovered cancer patients still may be virus carriers[30, 31]. The infection has not yet been found in contacts, this might be explained by the fact that all reported patients were subject to special care during home quarantine. Currently, there is lack of reliable relevant data about the general population in this respect. Thus, the difference between cancer survivors and general infected individual is worthy of more attention.
This study has several limitations. First, while the sample size is larger than the previous studies, only 56 cancer patients were included. With the limited number of cases, it is remain difficult to assess the exactrisk factors and to draw a solid conclusion about disease severity and mortality. At the same time, findings of the p-values of the statistical analysis require caution in their interpretation, and non-significant p values do not necessarily exclude difference between cancer survivors and cancer non-survivors.We hope the findings showed here will encourage a larger cohort study or some randomly controlled trials if possible. Second, some specific information were incomplete, such as immunoglobulins and Tcell subsets, which resulted in an incomprehensive analysis in disrupted immune function and immunosuppression. The data on other clinical information, however, as discussed in text, are indisputable. Third, this is a retrospective study. This study only describe the clinical course and outcomes of cancer patients with SARS-CoV–2 pneumonia. However, important data on anti-IL–6 therapy are lacking. More effort should be made to solve these questions correctly in future studies.
In conclusion, the infection rate and mortality of COVID–19 among cancer patients are considerable. Cancer non-survivors are characterized by more severe lymphopenia and a higher levels of IL2R, IL6 and IL10. Anti-cancer therapy may have an adverse effects on the severity of COVID–19 among cancer patients. Recovered cancer survivors still may be virus carriers.