Spontaneous recovery from cancer is very rare. And interestingly, some cases are associated with transmitted infectious diseases. In scientific journals, there were stories of patients whose neoplasms disappeared against the background of COVID-19. Experts believe that the reason is an unusual reaction of the immune system.
Unique cases during the pandemic
In January, researchers at the Royal Cornwall Hospital in the UK published a short note in the British Journal of Hematology. They said that a 61-year-old patient who had a failed kidney transplant three years ago was sent to them for treatment. Since then, he has needed hemodialysis. Doctors diagnosed Hodgkin’s lymphoma of the third stage — a malignant disease of the lymph nodes.
Soon, the patient was again admitted to the clinic with pneumonia, and the test for COVID-19 was positive. After 11 days, he was discharged; the lymphoma was not treated all this time. However, four months later, a CT scan did not find it.
A similar case was described in February by scientists from the Humanitas Research Clinic in Milan (Italy). They observed a 61-year-old man with pneumonia on the background of COVID-19, complicated by Hodgkin’s lymphoma.
In the course of treatment, they noticed that the tumor in the lymph node in the area of the intestine is decreasing, and then growing. At the same time, the patient lost cancer symptoms. Subsequent tomography did not reveal any neoplasms.
According to doctors, the immune system in these cases reacted unusually -together with the virus destroyed cancer cells. This happens very rarely.
In a 2012 paper, researchers from the University of North Carolina at Chapel Hill (USA) collected data on 18 people who had spontaneous remission of diffuse B-large cell lymphoma, one of the most common types of malignant blood diseases. Some have recovered from the infection.
The authors described observations on one of these patients — a 67-year-old woman. She went to the dentist with a swelling on her cheek. The biopsy showed that it was lymphoma. Two days before the start of chemotherapy, the patient was taken by ambulance to the hospital with a high fever, vomiting, diarrhea, and cough. Doctors diagnosed pneumonia, tests revealed the pathogenic bacteria Clostridium difficile in the body. The therapy was successful, and at the same time, the tumor disappeared.
The link between infections and spontaneous cancer cure has been known before. Back in the late 19th century, the American doctor William Coley gave cancer patients injections of streptococcal bacteria. He called it a vaccine. His contemporaries did not believe him, but today scientists have proved that Coley was on the right track.
Of course, we are not talking about COVID-19 as a cure for cancer. On the contrary, oncology is a risk factor for viral infection. “Coley vaccines” are now specially modified bacterial and viral strains (most commonly known as herpesviruses and adenoviruses) that infect only cancer cells.
Especially effective are such “vaccines” in combination with immunotherapy for malignant blood diseases: they not only directly destroy diseased cells, but also activate the immune system, forcing it to work selectively.
All these methods are still not without drawbacks and are being tested. But, according to experts, in most cases, cancer is not a disease that can be defeated by one drug. This means that “Coley toxins” and oncolytic viruses have great potential.