Clinical considerations for critically ill COVID-19 cancer patients: A systematic review

BACKGROUND The World Health Organization (WHO) on March 11, 2020, had declared the novel coronavirus disease 2019 (COVID-19) outbreak a global pandemic. The COVID-19 infection continues to be a pandemic and is currently causing overwhelming challenges to healthcare across the nations. Cancer patients represent a unique population vulnerable to COVID-19 infection due to their advanced age, intrinsic frailty, medical comorbidities, immunosuppression, and frequent health care visits for their underlying disease. Robust analysis of COVID-19 infection among cancer patients is crucial to aid in the optimal management of these patients. AIM To identify contributors of worse outcomes in patients with malignancy and COVID-19 and to describe the role of critical care. METHODS In this review, we summarized the information from seminal articles on the presentation and management of patients with COVID-19 and malignancy that were published before December 10, 2020. We searched the Pub Med and Medline database for "COVID-19" and "Cancer", "Malignancy". Studies published in English, including adults with malignancy and COVID-19 infection, were eligible to be included in this review. Studies on patients that provided details on malignancy, clinical presentation, management, and outcome were included. Various details of malignancy that were included are the site of cancer, histopathlogical type, stage, chemotherapy, and immunotherapy. Details of COVID-19 infection that were obtained are clinical presentation, the modality of testing, imaging, management, and outcome. Critical care details that were obtained were the type of the organ dysfunction and the requirement of organ support measures, requirement of noninvasive, invasive ventilation, management of vasopressor support, and outcome. Articles that did not have patient details, opinions, letters, and articles not published in English were excluded. All articles were reviewed by 2 independent clinicians. Articles were screened for the above terminologies by independent clinicians. RESULTS We identified two thousand one hundred eighty-six articles, among which fifty-five were studies that had included patient details pertaining to COVID-19 and cancer (Figure 1). Among these, eighteen studies were eligible and were included in this review as shown in Table 1. A total of 5199 cancer patients were reported. The mean age of patients across all the studies was 64.3 years with male predominance was noted in 12 studies. The clinical presentation and diagnosis of these patients were similar to the general population. Most commonly reported malignancies with COVID-19 infection were hematological in 44% of patients, followed by thoracic malignancy in 11% of patients. The mean number of cancer patients with COVID-19 requiring critical care was 16%. The mean mortality reported was 27.4%. Among the studies that reported the presence of organ dysfunction, respiratory failure was reported in 52% of patients, of which 11.7% required mechanical ventilation. 72% of COVID-19 cancer patients required hospitalization across all the studies. The factors which are associated with the worse outcome from COVID-19 infections among the cancer patients were male gender, age >= 65 years, presence of higher comorbidity burden based on Charlson comorbidity index and cumulative illness reporting scale > 6, and smoking history. CONCLUSION The majority of the cancer patients required intensive care due to respiratory failure and the need for mechanical ventilation. Appropriate contingency planning for these patients in terms of goals of care and judicious resource allocation in the resource-poor regions is the key. The factors associated with worse outcomes from COVID-19 infections were independent of ontological features such as tumor stage, disease status, or current provision of active anticancer therapy and it could be continued with caution.