Last week, a research team under the direction of Conghua Xie, MD, PhD, and Melvin LK Chua, MBBS, FRCR, PhD, reported in JAMA Oncology that patients with cancer at a hospital in Wuhan, China, experienced an increased risk of COVID-19 infection relative to other members of the community. In this interview with i3 Health, Dr. Chua and Dr. Xie discuss their findings and analyze possible factors contributing to the increased risk of COVID-19 infection in patients with cancer.
Can you comment on the significance of your results?
Melvin LK Chua, MBBS, FRCR, PhD, and Conghua Xie, MD, PhD: This is actually the first report that carefully examines the risk of COVID-19 in the general pool of patients with cancer. The previous report by Liang et al was in fact based on the percentage of cancer patients among all the recorded cases of COVID-19. Here, we carefully curated the medical records of over 1,500 patients, across all cancer types, who were either admitted for treatment or were on follow-up at our center. We found that the risk of COVID-19 was more than doubled in our cohort of patients with cancer relative to the community, with an odds ratio of 2.31. The crude incidence rate was 0.8%, with an upper boundary of 1.2%, which was startling to us, in truth!
Next, we dug deeper into the interactions with treatment, whether these patients were at risk because of chemotherapy or radiotherapy. It turns out that treatment was not a major factor in these COVID-19–positive patients: half of the patients were in fact on routine follow-up at the hospital. It remains to be determined if there are other factors, such as a baseline lower immune status in cancer patients, that might have predisposed them to this higher risk, apart from the repeated hospital visits.
Your study noted a particularly high incidence of COVID-19 in patients with non–small-cell lung carcinoma (NSCLC), especially among those over the age of 60. To what do you attribute this finding?
Dr. Chua and Dr. Xie: It was an interesting finding that the majority of these COVID-19–positive cancer patients had lung cancer. Lung and gastrointestinal cancer patients comprised half of the 1,524 patients with cancer, a fact not published in the paper. The question of why COVID-19 was more common among lung cancer patients is intriguing and ought to be further investigated. A simple and plausible explanation would be that the patients with lung cancer likely have an abnormal respiratory epithelium that facilitates the entry of the virus, and subsequently, the immunocompromised host provides a favorable microenvironment for the virus to reside and propagate.
It is also noted that age was a risk factor, but we believe that this may be a biased confounder rather than a true association, given that cancer patients are generally older. We refer to the larger study by Guan et al, which showed that age was not a risk factor for COVID-19 infection; rather, it was a risk factor for infection severity.
What further research needs to be done on this issue?
Dr. Chua and Dr. Xie: We believe that our study is merely a beginning to the research on COVID-19 impact in cancer patients. Several more questions remain.
We need to more accurately determine the risk of COVID-19 and severe COVID-19 in cancer patients; we will need aggregation of datasets globally to yield larger numbers so that we can derive tighter estimates. We need to elicit and confirm the susceptibility of lung cancer patients and the mechanisms underpinning this. Do these patients harbor seroconversion—immunoglobulin G (IgG) of severe adult respiratory syndrome coronavirus 2 (SARS-CoV-2)—in the long term, post infection? We need to determine the interaction between cancer treatments and COVID-19 in patients, whether treatments in fact worsen the severity of infection.
Finally, we need to ascertain the impact of this pandemic on the overall outcomes of cancer patients. This is yet to be determined, since patients are having their treatments delayed or interrupted during this period. This will be a key question, one of crucial importance to the public regarding the impact of such a pandemic on global heath.
About Dr. Chua and Dr. Xie
Melvin LK Chua, MBBS, FRCR, PhD, is a clinician-scientist at the Division of Radiation Oncology of the National Cancer Centre, Singapore, and an Assistant Professor with the Duke–National University of Singapore (Duke–NUS) Medical School. His research focuses on prognostic and predictive biomarker discovery and on drug development and clinical trials in prostate, nasopharynx, and head and neck cancers. Dr. Chua serves on several journal editorial boards, including as the Editor-in-Chief for the Annals of Nasopharynx Cancer and as the Head and Neck Cancer Section Editor of the International Journal of Radiation Oncology, Biology, Physics. He also serves on several committees for the American Society of Clinical Oncology (ASCO) that are involved in improving clinical care, education and research initiatives in the low- and middle-income countries.
Conghua Xie, MD, PhD, is the Medical Director of the Department of Radiation and Medical Oncology at Zhongnan Hospital of Wuhan University, Wuhan, China. He leads a department consisting of more than 200 medical doctors and allied health staff and was instrumental in leading Zhongnan Hospital to achieve the status of a Tier 3 (highest) tertiary cancer center in China. Dr. Xie is also a Full Professor at Wuhan University. His academic interests include the discovery of biomarkers for the screening of early lung cancers, the interaction between radiation and the antitumor immune response, and the development of clinical trials for lung and upper gastrointestinal cancers.
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Transcript edited for clarity. Any views expressed above are the speakers' own and do not necessarily reflect those of i3 Health.