A first-of-its-kind study examining the assumption that cancer patients are an at-risk group for COVID-19 finds that these patients do not get infected any more than the general population and do not suffer from more severe disease symptoms. In fact, based on their findings, the researchers hypothesize that cancer treatments may affect the patients’ response to COVID19-induced “cytokine storm.”
From the moment the COVID-19 pandemic broke out, medical teams around the world operated under the assumption that cancer patients were an at-risk group in terms of contracting the virus. Defining cancer patients as an at-risk group had far-reaching implications for their treatment – this without any prior scientific basis. Patients were afraid to seek treatment for fear of contracting the coronavirus in hospitals, and in some countries, guidelines were issued for postponing oncology treatments in certain situations.
A new study conducted by researchers at Rambam Medical Center and the Technion reveals surprising findings, namely that cancer patients may not be associated with the broad range of at-risk groups of people suffering from morbidities. The research was led by Professor Yuval Shaked, head of the Rappaport -Technion Integrated Cancer Center (R-TICC) and Professor Irit Ben Aharon, director of the Division of Oncology at Rambam and principal investigator at the R-TICC, in collaboration with Dr. Tal Goshen-Lago, head of the Translational Research Division of Oncology at Rambam. The findings were published in Cancers, in a special edition dealing with the impact of the coronavirus on cancer patients.
The study included 271 participants, including 164 cancer patients, who came to the Rambam Medical Center to receive ongoing treatment for their disease, and a control group of 107 healthy employees among the medical staff. In the study, which was conducted between March and June 2020, all participants underwent blood tests, at three different times, to examine changes in the profile of the immune system. The test monitored three antibodies – IgG, IgM and IgA – that represent antibody formation at different times of virus exposure.
“We were surprised to find that cancer patients and health subjects developed antibodies at similar rates,” said Prof. Ben Aharon. “2.4% of cancer patients who participated in the study and 1.9% of participants in the healthy control group developed antibodies for the coronavirus and all were asymptomatic. Moreover, throughout the entire study period, no symptomatic coronavirus patients were detected in the study population and among the general population of our oncology patients.” According to Prof. Ben Aharon, the CyTOF technology was used to map immune system cells, and a significant difference was found between the immune profile of cancer patients who were positive for coronavirus antibodies and the immune profile of the positive staff members.
“Our hypothesis is that the different response of cancer patients to the disease is related to the fact that anti-cancer treatment changes the profile of the immune system,” said Prof. Shaked. “The myeloid cells, which are vital cells in the immune system, are severely damaged by the coronavirus. In the general population and in the medical staff that participated in the study, the virus reduces the rate of myeloid cells by about 90%; in cancer patients, however, it reduces them by only 50%. This fact gives cancer patients relative protection.”
Prof. Ben Aharon added that the hypothesis is that anti-cancer treatments may change the profile of the immune system and its function which may limit the ability of the coronavirus to induce severe inflammation in patients receiving these treatments. The researchers estimate that this is why the proportion of cancer patients with non-hematological malignancies who develop severe disease is relatively low compared to that of the general population according to the literature, and that severity may be affected by other comorbidities. The mechanism for this observation is being further explored nowadays.