COVID-19 infection risk in cancer patients
Dr. Liang Tzung Lin
Professor, Department of Microbiology and Immunology
Joint-Appointment Professor, Master Program in Global Health and Development
Joint-Appointment Professor, Ph.D. Program in Global Health and Health Security
Elevation of SARS-CoV-2 (Coronavirus) viral entry genes and dampening of the immune system following cancer treatment may make cancer patients more susceptible to COVID-19.
Original Research Article: Elevation in viral entry genes and innate immunity compromise underlying increased infectivity and severity of COVID-19 in cancer patients
Globally Covid-19 infection has surpassed over 150 million cases, and more than 3 million deaths have been reported by WHO as of early mid-2021. With multiple countries battling precarious second and third waves and more dangerous variants emerging in different parts of the world, COVID-19 is ranked as one of the top ten deadliest pandemics seen in human history alongside the Black Death, Plague of Justinian, Spanish flu, and a few other plagues much to our horror. How did a virus so simple bring the entire world to a worrying halt and change the definition of normalcy in our lives? What evolutionary brilliance that this virus possesses in the era where medical advancement is at its best and yet failed to curb the pandemic from spreading so sporadically? A Professor from the University of Cambridge answers these questions by elucidating the deceptive ability of this virus that dampens the immune system by shutting down the release of a chemical that acts as a warning signal. This enables the virus to become highly infectious even before you “fall sick”, making it so deadly and undetectable from an early stage of infection.
In addition to being highly contagious, the biggest concern in COVID-19 management is when patients have other comorbidities such as diabetes, heart condition, high blood pressure, and cancer as they increase the severity of the infection. Cancer patients, in particular, are four times more likely to be infected by COVID-19 compared to the general population making it a concern of the health care system. Apart from increased vulnerability, cancer patients are also known to have more severe complications when they get infected by this virus. Hence, identifying treatment and management gaps in COVID-19 becomes vital to reduce the morbidity and mortality of both diseases.
In line with that, researchers from Taipei Medical University, Taiwan, alongside those from the University of Toronto, Canada, investigated the intricate relationship between cancer patients and COVID-19 infection to understand possible modifications needed in the clinical management of the disease. Large-scale genome-wide transcriptional analysis on normal and tumor tissues of adults and children was done to study relevant genes and other factors that thrive the infection. RNA expression of three significant genes responsible for SARS-CoV-2 entry into the body, including ACE2, TMPRSS2, and CTSL, were found to be upregulated in different adult tumor tissues tested. On the contrary, pediatric cancer samples were shown to have lower expression of viral entry genes, reflecting a lower incidence of COVID-19 infection among children. Chemotherapy and radiotherapy in cancer patients contributed to a temporary increase in the viral entry genes and dampening of the immune system during the treatment period, thereby increasing the risk of infection in this cohort. The findings published in Nature’s Scientific Reports claim that, compared to the opposite sex, males are predisposed to a higher risk of infection. Likewise, smokers were also identified to express increasing CTSL expression with age. A previous study in China aimed to construct a risk map for tissues susceptible to COVID-19 infection based on ACE2 expression. Nevertheless, this study has comprehensively encompassed two additional essential genes and other factors, including age, sex, smoking, and cancer treatments. These findings create a framework to further investigate the link between cancer and COVID-19 to mitigate the risk of infection by optimizing treatment scheduling and close monitoring.
Existing COVID-19 treatment and management mostly follow the empirical guideline, as its association with a lot of diseases is yet to be unraveled. Consequently, the effectiveness of COVID-19 management could be compromised if the increased risk of infection and the corresponding reasons for different ailments are not investigated. To recapitulate, the outcome of this study will provide a fundamental to develop treatment guidelines for COVID-19 in cancer patients. The findings are imperative to guide clinicians and oncologists on managing COVID-19 in cancer patients to modify cancer treatment schedule or sequence appropriately if possible. As the infection is spreading faster than ever, every possible endeavor to understand the disease and its physiology is vital to reducing this infection’s morbidity in different conditions. Studies like this that contribute to the knowledge of COVID-19 and its management will complement major ongoing efforts like vaccinations in an attempt to end this pandemic worldwide and restore the health of the global community. Such is ideally crucial to uphold the United Nations’ Sustainable Development Goal (UNSDG) 3: Good health and wellbeing, which aims to improve global public health. With the pandemic being the current health emergency worldwide, every effort to improve its management becomes an integral part of fighting the battle.
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