As we are all facing new challenges and uncertainties amidst the worldwide coronavirus (COVID-19) pandemic, I think that it is important to acknowledge COVID-19 as a part of my blog series on cancer biology. As many of us already know, elderly people (aged 65 and above) and other immunocompromised individuals are at a higher risk of infection by COVID-19 and more likely to develop severe symptoms or death once infected. However, you may not realize that individuals with a history of cancer or currently battling the disease are notably more susceptible to COVID-19 infection because they have an immunosuppressive state. That is cancer patients have a much weaker immune system compared to other individuals due to the nature of their disease as well as anticancer treatments. Certain cancers, including lymphomas, multiple myeloma and leukemia, negatively affect the immune system and can change the way that our bodies respond to foreign pathogens, such as the COVID-19 virus. Additionally, radiation therapy, immunotherapy, chemotherapy and surgery, all common cancer treatments, can affect your immune system too. Chemotherapy is most likely to weaken the immune system because it targets rapidly dividing cells, which cancer cells are – but so are many normal cells in the body – which also get targeted (killed). Typically, your healthy cells can repair the damage caused by chemotherapy once treatment ends. However, if patients are currently undergoing treatment as the COVID-19 pandemic evolves, their immune system will be extremely weakened making them very vulnerable to infection. Therefore, some healthcare providers have been working with their patients to make a decision on temporarily halting treatment or delaying the start date in some cases.
Knowing that cancer patients are immunocompromised and likely more susceptible to COVID-19 infection, researchers in China, the initial epicenter of the disease, investigated the actual relationship between cancer and COVID-19. They analyzed 1590 cases from over 500 hospitals across China where all patients were diagnosed with confirmed COVID-19 acute respiratory disease. They found that 1% of the COVID-19 cases had a history of cancer which is higher than the overall incidence of cancer in the Chinese population (0.29%). Of the cancer patients, lung cancer was the most frequent type.
Most notable, patients with cancer were observed to have a higher risk of severe events – severe events were recorded as admission to the intensive care unit requiring invasive ventilation or death – compared with patients without cancer. (39% versus 8%). Overall this study concluded that patients with cancer might be at an increased risk of COVID-19 when exposed and experience a poorer prognosis once infected.
With the data from their study in The Lancet supporting the hypothesis that cancer patients are more susceptible to COVID-19, Liang et al., proposed three major strategies for individuals with cancer during this COVID-19 crisis:
- An intentional postponing of adjuvant chemotherapy or elective surgery for stable cancer should be considered in endemic areas.
- Stronger personal protection provisions should be made for patients with cancer and cancer survivors
- More intensive surveillance and treatment should be considered when patients with cancer are infected with the coronavirus, especially in older patients
The reminder that immunocompromised individuals, including cancer patients (approximately 40% of the US population will be diagnosed with cancer at some point in their lifetime), are more susceptible to COVID-19 should be a stark reminder for all of us. It is essential that both cancer patients and healthy individuals follow all of the recommendations set out by the CDC as a service to ourselves, our families and to others who may be more vulnerable. It is especially important right now that cancer patients, caregivers and everyone else (healthy or not) follow the social distancing and self isolation guidelines. This is our last defense against a rapidly spreading virus and any extreme measures we take now, will benefit us greatly in the future.
For further information visit: https://www.cdc.gov/coronavirus/2019-nCoV/index.html
Liang, Wenhua, et al. “Cancer Patients in SARS-CoV-2 Infection: a Nationwide Analysis in China.” The Lancet Oncology, vol. 21, no. 3, 2020, pp. 335–337., doi:10.1016/s1470-2045(20)30096-6.