What does coronavirus do to our bodies and how can it affect cancer patients?
The constant information flow about coronavirus can feel overwhelming. People suffering from cancer and their families might feel especially worried in these uncertain times. This blog post aims to explain how coronavirus affects our bodies and what this means for cancer patients.
Coronaviruses are a large family of viruses known to cause illnesses ranging from the common cold to more severe diseases. The early 2020 outbreak of infectious respiratory disease is caused by a novel Severe Acute Respiratory Syndrome (SARS) coronavirus, named SARS-CoV-2, and triggers the development of coronavirus disease 2019, abbreviated as COVID-19.
Researchers from multiple disciplines are combining efforts to understand COVID-19 as we don’t know a lot about it yet. Around 80% of infected people suffer mild or moderate respiratory illness and recover from COVID-19, while others might be asymptomatic. It has been seen that the elderly and people with comorbidities (i.e. cardiovascular disease, diabetes, chronic respiratory disease, and cancer) can experience severe complications, frequently as a form of pneumonia.
Viruses can be described as parasites, meaning that they require a host (e.g. a human) and a particular environment within a host cell to survive. How does SARS-CoV-2 infect a human cell? Why does this cause disease?
SARS-CoV-2 is primarily transmitted by respiratory droplets to others in direct or close contact with symptomatic people, or by contact with contaminated objects and surfaces. Then, the virus infects and enters cells found in the human respiratory tract (e.g. lungs) using its spikes which interact with proteins, called ACE2 receptors. Consequently, the virus can replicate in the host cell and spread to neighbouring lung cells.
This raises an alarm to the immune system. Generally, if a person is in good health, the body can start a specific immune response to eliminate the virus and impede disease progression to severe pneumonia stages. In critical cases, the antiviral response can be impaired and cause a rapid onset of inflammation in the lungs, leading to severe breathing difficulties and in some cases, respiratory failure.
The immune system protects us from disease and infection caused by virus, bacteria, fungi or parasites. The immune system is especially important to cancer patients because it helps to fight cancer, however some cancers can affect the immune response.
Cancer can cause immunosuppression by spreading into the bone marrow. The bone marrow is responsible for producing white blood cells to fight invaders, such as SARS-CoV-2, cancer can stop it from making enough cells, thereby weakening the immune response. Certain types of blood cancer can directly affect our immune system, such as leukaemia or lymphoma, but it can happen with other cancers too. Some cancer treatments can also cause a drop in white blood cell production in the bone marrow and might temporarily weaken the immune system. These include chemotherapy, radiotherapy and targeted cancer drugs.
On the other hand, immune cells can recognise cancer cells as abnormal and kill them. Sometimes this is not enough to stop it, but there are new drugs that aim to boost the immune system to fight cancer, known as immunotherapies.
As a result of the outbreak, specialists are working together to guide clinical decision-making, to coordinate cancer services and minimise risk of infection. Doctors aim to ensure cancer care doesn't stop for a pandemic. To do so, “cancer hubs” have been designated to be coronavirus-free centres, supporting hospitals to deliver cancer care. This means you might be asked to go to a different hospital for surgery, however your current oncologist will remain in charge of your overall care. Likewise, you may have consultancy calls to reduce hospital visits.
Coping with cancer diagnosis and treatment is difficult, and for many the coronavirus is an extra concern. Cancer treatment usually feels urgent, and it can be unsettling to face changes to your treatment plan. You might have to take chemotherapy drugs as a tablet or injection, or have longer breaks between cycles for targeted cancer drugs or immunotherapies. Talking to your health team about the effect of the coronavirus outbreak on your particular treatment plan can help you understand possible modifications and manage them. They will support you and help protect you from developing COVID-19.
You should still contact your GP if you notice any abnormal changes or if you develop any possible symptoms of cancer. Your doctors are ready to help you safely. If your symptoms are due to cancer, always remember that an early detection increases chances of successful treatment.
CCG.ai’s top priority remains developing tools that will help clinicians to provide the best cancer care possible, and by following the global guidance to tackle COVID-19 we hope we can get back to beating cancer as soon as possible.