Viral Infections and Cancer: Does Covid-19 Trigger Dormant Cells?

Recent scientific research shows that severe respiratory infections like Covid-19 may trigger dormant cancer cells in the body. The intense inflammatory process, which occurs especially when the immune system fights an infection, can pave the way for these cancerous cells to wake up. This situation once again reveals just how complex the relationship between infection and cancer is, and why it requires careful monitoring.

Our bodies are in a constant state of defence against external threats. However, severe infections can disrupt the balance of the immune system. For individuals who have undergone cancer treatment or are currently in active treatment, protecting themselves from such viral infections is of vital importance.

• Viruses like Covid-19 and influenza risk activating silent cancer cells by altering the immune response.
• It has been a medical fact for many years that viruses such as Hepatitis B, Hepatitis C, and HPV can directly lead to cancer.
• Due to a weakened immune system, Covid-19 infections in cancer patients can be much more severe compared to healthy individuals.
• Vaccination is one of the most effective methods for both preventing viral infections and reducing the risk of virus-related cancers.
• Keeping the immune system strong, managing chronic diseases, and not taking infections lightly are the foundations of the healing process.

What is a Dormant Cancer Cell?

After cancer treatment, some cells that could not be completely destroyed but have stopped multiplying may remain in the body. In this state, known in medical terms as cellular dormancy, cancer cells can hide in certain parts of the body for years, or even decades, without showing any symptoms. Dormant cancer cells are kept under constant pressure by the immune system, preventing them from multiplying. These cells are usually micro-metastases that detach from the primary tumour, travel through the bloodstream, and settle in distant tissues like the lungs, liver, or bone marrow.

As long as the immune system is strong, these cells remain inactive. However, a major trauma in the body, a severe infection, or extreme stress can distract the immune system. When immune cells leave the area to fight an infection, or when intense inflammation occurs in the body due to an infection, the mechanisms suppressing these dormant cells weaken. The cells can take advantage of this opportunity to begin dividing and multiplying again. Therefore, it requires great care for individuals with a history of cancer to protect their overall health.

Which Viruses Can Be Associated with Cancer?

The answer to the frequently asked question "do viruses cause cancer?" has long been clearly understood in the medical world. Some viruses pave the way for cancer development by directly interfering with the DNA structure of human cells or by causing chronic inflammation. These are called oncogenic viruses. A significant portion of cancer cases worldwide is directly linked to viral infections.

For example, Hepatitis B and Hepatitis C viruses can cause long-term damage to liver cells, leading to liver cancer. The Human Papillomavirus (HPV) is the primary cause of cervical cancer and is also associated with head and neck cancers. The Epstein-Barr virus (EBV), which causes the infection commonly known as kissing disease (mononucleosis), can play a role in the development of various types of lymphoma later in life. The most effective way to protect against the cancer-causing effects of these viruses is to adhere to vaccination programmes. Hepatitis B and HPV vaccines act indirectly as cancer vaccines by preventing the initial infection.

Infection and Cancer: How Does Covid-19 Affect the Process?

Recent scientific studies on the relationship between Covid-19 and cancer offer striking data regarding the effects of infections at the cellular level. Laboratory research conducted on mice in collaboration with the University of Colorado in the US and Utrecht University in the Netherlands has shown that respiratory infections like Covid-19 and influenza can awaken dormant cancer cells. Researchers found that the virus does not directly alter the DNA of cancer cells, but rather, the body's excessive immune response to the virus causes this awakening.

During an infection, intense inflammation occurs in the lungs. Neutrophils, the frontline soldiers of the immune system, flock to the area to fight the virus. During this battle, neutrophils create net-like structures (NETs - Neutrophil Extracellular Traps) to catch the viruses. However, these nets and the inflammatory substances secreted also alter the tissue surrounding dormant cancer cells, creating a suitable environment for them to become active again. This mechanism proves that respiratory infections should not be seen as a simple cold, and that they can leave lasting effects at the cellular level, especially in high-risk individuals.

The Course of Covid-19 and Risks in Cancer Patients

Covid-19 infection in cancer patients is a process that must be managed much more carefully due to the nature of the disease and the treatments applied. The immune systems of patients receiving chemotherapy, radiotherapy, or targeted therapies are more suppressed compared to healthy individuals. A drop in the number of white blood cells leaves the body vulnerable to external viral or bacterial threats.

Scientific data shows that hospitalisation, intensive care requirements, and mortality rates in cancer patients who contract Covid-19 are significantly higher than in individuals with no history of cancer. Patients battling blood cancers like leukaemia or lymphoma, as well as lung cancer, are in the highest risk group. When the respiratory distress caused by the infection combines with the damage cancer has caused in the lungs, the clinical picture can deteriorate rapidly. During this period, it is of great importance for patients to take precautions in line with the guide to protection against increasing viral infections as winter approaches.

How Should Cancer Patients Protect Themselves from Covid-19?

Individuals undergoing cancer treatment or those who have survived cancer in the past need to take extra care in their daily lives to protect themselves from viral infections. Simple but effective precautions significantly reduce the risk of infection.

• Adherence to Vaccination Programmes: Getting up-to-date doses of Covid-19 vaccines prevents severe illness. Additionally, with a doctor's approval, getting the flu vaccine (influenza) and pneumonia vaccine every year is strongly recommended.
• Personal Hygiene and Mask Use: High-protection masks must be used in crowded, enclosed, and poorly ventilated environments. Hand hygiene should be prioritised, and hands should be washed frequently with soap and water.
• Social Distancing: Contact with individuals showing signs of illness (coughing, sneezing, fever) should be avoided.
• Diet and Sleep Routine: A balanced diet rich in protein, vitamins, and minerals should be followed to support the immune system. Adequate and quality sleep is indispensable for the body's repair processes.
• Regular Doctor Check-ups: Cancer follow-ups should not be neglected, and in case of any suspected infection, a specialist should be consulted without delay.

When to See a Doctor?

In individuals undergoing cancer treatment or those with suppressed immune systems, infection symptoms can progress very quickly. A mild sore throat or fatigue can soon turn into a severe respiratory infection. If you experience a persistent fever of 38 degrees Celsius or higher, severe cough, yellow or green sputum, extreme fatigue, or muscle and joint pain, you should consult your treating physician or a healthcare facility without delay.

Some symptoms require emergency medical intervention. Severe shortness of breath felt even while resting, a feeling of pressure or pain in the chest, bruising on the lips or nail beds, confusion, difficulty waking up, or excessive sleepiness are life-threatening signs. If you observe any of these symptoms in yourself or a loved one, you should immediately call the 112 Emergency Call Centre or go to the emergency department of the nearest fully equipped hospital.

The Process and Multidisciplinary Approach at BHT CLINIC

The management of infectious diseases and cancer processes is directly linked to the body's overall metabolic balance. Metabolic issues such as diabetes, obesity, or thyroid diseases can disrupt the functioning of the immune system and lower resistance to infections. At BHT CLINIC İstanbul Tema Hastanesi, our patients' treatment processes are handled with a multidisciplinary approach. Our Endocrinology and Metabolism department offers personalised treatment plans using the latest technologies to control metabolic conditions that increase the risk of infection.

Our emergency department, which provides 24/7 service at our hospital, enables rapid diagnosis and intervention in potential infection cases. When cancer patients present with a suspected infection, our infectious diseases, oncology, and endocrinology specialists work in coordination to determine the safest treatment protocol. Take care not to neglect your check-ups to protect your health and minimise risks.

To get detailed information and consult with our specialist doctors, you can book an appointment.

Frequently Asked Questions

Does Covid-19 directly cause cancer?

No, according to current scientific data, there is no evidence that the Covid-19 virus directly alters cell DNA to initiate a new cancer. However, the severe inflammation caused by the virus can trigger the awakening of pre-existing, dormant cancer cells in the body.

What are dormant cancer cells?

Dormant cancer cells are inactive cells that remain in the body after cancer treatment but have stopped multiplying. These cells, suppressed by the immune system, carry the risk of reactivation when immunity weakens due to severe infections or trauma.

Should cancer patients get the Covid-19 vaccine?

Yes, cancer patients are in a high-risk group for Covid-19 because their immune systems are weak. Getting vaccinated according to the schedule determined by your doctor significantly reduces the risk of severe illness and hospitalisation.

Which viral infections increase the risk of cancer?

Hepatitis B and Hepatitis C viruses can pave the way for liver cancer, HPV (Human Papillomavirus) for cervical and head-neck cancers, and the Epstein-Barr virus for certain types of lymphoma. Vaccination is the most effective method of protection against these viruses.

Do the flu or a cold trigger cancer?

A simple cold is not expected to trigger cancer. However, laboratory studies show that respiratory infections causing severe lung inflammation, such as influenza (the flu), can cause cellular changes that may awaken dormant cancer cells, much like Covid-19.

This article is for informational purposes only; please always consult your doctor for diagnosis and treatment.