While it’s well established that cancer patients are at a higher risk of getting severe COVID-19, researchers have found a potential new link between the two conditions. The study, published in the journal Scientific Reports, suggests that a person who develops severe COVID-19 might also be living with undiagnosed cancer.
The investigation, which its authors call the first of its kind, found that people hospitalized with severe COVID-19 had a 31 percent increased likelihood of being diagnosed with cancer in the months afterwards, compared with people hospitalized for other reasons and people with COVID-19 that did not require hospitalization.
The analysis took into account a number of variables that could influence cancer risk, such as age, sex, comorbidities (other health problems besides COVID-19), and addictive disorders.
“If our findings are reproduced elsewhere, screening for some cancers — for example, colon, kidney, lung, hematological [blood] — in case of severe forms of COVID could allow for early detection and treatment,” says Antoine Flahault, MD, a study author and director of the Institute of Global Health at the University of Geneva in Switzerland.
Results Based on a Large Pandemic Population
The investigation included over 41,000 individuals in France who were hospitalized in an intensive care unit (ICU) due to COVID-19, and compared cancer incidence in that group to almost 714,000 people who were not hospitalized for COVID-19. The average patient age was about 60, and just over two-thirds were men; none had a history of cancer in the previous five years.
Dr. Flahaut and his colleagues examined health records of those hospitalized from February 15, 2020, until August 31, 2021, a period covering the beginning of the pandemic until the end of the fourth wave in France.
Follow-up was from the date of ICU admission until an end date of December 31, 2021, allowing for a minimum of four months.
During this period, cancer incidence was 2.2 percent in the COVID-19 intensive care group versus 1.5 percent in the control group.
Certain Types of Cancer Were More Prevalent
This risk was significantly higher for particular types of cancer: renal (kidney), hematological (blood), colon, and lung. Focusing on blood cancers alone, scientists noted that the hospitalized COVID-19 group had a significantly greater likelihood of being diagnosed with leukemia, myeloma, or non-Hodgkin lymphoma compared with the controls.
On the other hand, there was no difference between the two groups for the following cancers: Hodgkin’s lymphoma, melanoma, and cancers of the breast, prostate, kidney, liver, bladder, or uterus.
“Knowing this may raise the question of targeted screening for these specific cancers,” says lead author Adeline Dugerdil, MD, a resident physician at the University of Geneva in Switzerland. “So, the question should be: Should we provide screening for these specific cancers for people discharged from intensive care with severe COVID?”
What’s Driving the Higher Risk of Cancer Detection?
As to why certain cancers were more prevalent among those with severe COVID-19, the answer is still to be determined.
“I do think that the lung cancer risk seems clear, as COVID-19 virus is most likely to impact lungs,” says Manali Patel, MD, associate professor of medicine specializing in oncology at Stanford Health Care in California. She adds that higher incidence of renal, colon, and hematological malignancies supports the notion that COVID-19 virus is a vascular disease, meaning it is related to the blood vessels.
Dr. Patel, who was not involved in the study, stresses that the analysis does not show that COVID-19 causes any of these cancers.
“The study is interesting but it remains unclear if this association between COVID-19 infection and cancer is, as the authors suggest, a biomarker for undiagnosed cancer or if COVID-19 is a promoter for cancer,” she says.
More research is needed to figure out if COVID-19 may actually be a cancer-causing virus, similar to human papillomavirus (HPV) and Epstein-Barr virus, according to Patel.
The researchers add that the undetected cancers may suppress the immune system, which could be the reason why some patients experienced severe COVID-19 in the first place.
“An underlying condition which leads to some form of immunosuppression, such as preexisting cancers, could be seen as a risk factor for developing a severe form of COVID,” says Flahault.
Dr. Dugerdil points out that all cancers can have an immunosuppressive effect, but it is possible that some have a more specific effect on certain immune pathways that are involved in the defense against the coronavirus behind COVID-19. “This deserves further biological investigation,” she says.
The research highlighted two other intriguing points worthy of further exploration. Women with severe COVID-19 had a stronger risk of cancer compared with men, and cancer detection was more likely in people younger than 60. The strongest association was found in women under 60 years old.
“There is more data that is coming out now that we are three years into research on COVID-19 with the association with cancer,” says Patel. “There is some sort of linkage but it’s not quite clear what that linkage is as of yet.”
This content was originally published here.
