Health

‘Unusual’ cancers emerged after pandemic. Doctors ask if covid is to blame.

ROCK HILL, S.C. — Kashyap Patel looked forward to his team’s Friday lunches. All the doctors from his oncology practice would gather in the open-air courtyard, under the shade of a large magnolia tree, and catch up. The atmosphere was rather light and optimistic. But that week he was in distress.

It was 2021, a year into the coronavirus pandemic, and as he slid into a chair, Patel shared that he had just seen a patient in his 40s with cholangiocarcinoma, a rare and rare cancer. deadly bile duct disease that usually strikes people in their 70s and 80s. At first there was silence, then one colleague after another said that they had recently treated patients with similar diagnoses. Less than a year after that meeting, the office had recorded seven such cases.

“I’ve been practicing for 23 years and I’ve never seen anything like this,” Patel, CEO of Carolina Blood and Cancer Care Associates, later recalled. Asutosh Gor, another oncologist, agrees: “We were all shaken. »

There were other oddities, too: several patients with multiple types of cancer appearing almost simultaneously, and more than a dozen new cases of other rare cancers.

Increasingly, Patel found himself with a troubling thought: Could the coronavirus be inflamed? the embers of cancer?

The rise in advanced aggressive cancers since the start of the pandemic is confirmed by some early national data and by a number of major cancer institutions. Many experts have mostly dismissed this trend as an expected consequence of the healthcare disruptions that began in 2020.

The idea that certain viruses can cause or accelerate cancer is not new. Scientists have recognized this possibility since the 1960s, and today researchers estimate that 15 to 20 percent of all cancers worldwide arise from infectious agents such as HPV, Epstein-Barr and Hepatitis B.

It will likely be many years before the world has conclusive answers about whether the coronavirus is complicit in the increase in cancer cases, but Patel and other concerned scientists are calling on the U.S. government to make this question a priority , knowing that it could affect treatment and management. millions of cancer patients for decades to come.

“We are completely understudying this virus,” said Douglas C. Wallace, a geneticist and evolutionary biologist at the University of Pennsylvania. “The effects of this repeated phenomenon throughout our lives will be much greater than people think.”

But there is no real data linking SARS-CoV-2 to cancer, and some scientists remain skeptical.

John T. Schiller, a researcher at the National Institutes of Health and a pioneer in the study of cancer-causing viruses, said pathogens known to cause cancer persist in the body long term. But the class of respiratory viruses that includes influenza and RSV — a family that coronavirus is a part of — infect a patient then usually disappears instead of lingering and does not appear to cause cancer.

“You can never say never, but this kind of virus doesn’t suggest it’s involved in cancers,” Schiller said.

David Tuveson, director of the Cancer Center at Cold Spring Harbor Laboratory and former president of the American Association for Cancer Research, said there is no evidence that the coronavirus directly transforms cells to make them cancerous. But that may not be the whole story.

Tuveson said a number of small, early studies — many published in the past nine months — suggest that coronavirus infection can induce an inflammatory cascade and other responses that, in theory, could exacerbate the growth of cancer cells.

He wondered if it might be more of an environmental stressor – such as tobacco, alcohol, asbestos or microplastics.

“Covid destroys the body, and that’s where cancers can appear,” Tuveson said, explaining how autopsy studies of people who died from Covid-19 have shown prematurely aged tissue.

Even as the first wave of the coronavirus hit the United States, public health officials predicted a surge in cancer cases. A Lancet Oncology article analyzed a national registry showing an increase in stage 4 disease — the most severe — for many types of cancer in late 2020. Baptist Health Miami Cancer Institute, UC San Diego Health and other major institutions have released data showing a continued increase in late 2020. stage cancers.

Xuesong Han, scientific director of health services research at the American Cancer Society and lead author of the Lancet Oncology study, attributed the jump to people delaying or skipping care because of fears about the virus or for economic reasons, as well as cultural factors. language barriers and discrimination. But Han acknowledged that the biological mechanisms of SARS-CoV-2, the virus that causes covid-19, could be at play.

“I don’t have data to support this opinion,” Han said. “But it’s an important issue to follow.”

“I hope we are wrong”

The human body is made up of billions of cells in a constant state of growth, repair and death. Most of the time, cells with damaged DNA repair themselves or simply disappear. Sometimes they begin to collect errors in their genetic code and rampage uncontrollably into tumors, destroying body parts.

Afshin Beheshti is chair of the International COVID-19 Research Team, a group of scientists from eclectic backgrounds who came together during the pandemic to brainstorm novel ways to combat the virus. Beheshti has a background in cancer biology and he said as the science on the virus evolves – including studies showing widespread inflammation following infection, impact on the vascular system and infection in multiple vulnerable organs to the development of cancer stem cells – he continued to think “the signals seemed to be linked to early changes in the cancer.

“It was constantly on my mind,” he said.

About a year ago, Beheshti, a visiting scholar at MIT and Harvard’s Broad Institute, contacted Patel, former president of the Community Oncology Alliance, a national group of independent cancer specialists, and they organized a symposium with other scientists who concluded There is compelling evidence suggesting links between coronavirus and cancer.

“I hope we’re wrong,” Beheshti said. “But unfortunately, everything points to that being the case.”

The group’s loosely affiliated members are launching research studies that attempt to piece together the puzzle of coronavirus infection, long covid and cancer.

Wallace – the University of Pennsylvania scientist considered one of the fathers of the field of human mitochondrial genetics, which explores the power plants that power human cells – studies how covid affects energy production in cells and how this might influence vulnerability to cancer.

In addition, biodata experts are sequencing the genetic profiles of the organs of people who have died from covid and have undergone autopsies.

And a team from the University of Colorado is studying whether covid wakes up dormant cancer cells in mice. Their provocative findings, according to a preliminary report published in April, showed that when cancer-surviving mice were infected with SARS-CoV-2, dormant cancer cells proliferated in the lungs. They found similar results with the flu virus.

Ashani Weeraratna, a physician and professor at the Johns Hopkins Bloomberg School of Public Health, said the Colorado study, which she was not involved in, is part of a new area of ​​work that has emerged over the past decade and who studies what stimuli can wake you up. cancer cells.

She said this is consistent with research highlighting the importance of the immune system in activating cells from dormancy, so it makes sense that “something like the flu or covid that triggers inflammation could change in the microenvironment.” immune”. But the results surprised her because “it’s rare for the data to be this striking.”

Weeraratna said that while she believes the results of the Colorado study are important, they should be interpreted with caution. Mouse studies often do not translate to human experiments. She said it was also important to point out that research and other recent articles focused on covid and cancer involve acute infection or long covid; they do not suggest a link between the coronavirus vaccine and cancer – misinformation spread by some anti-vaccine groups in recent months.

Still, Weeraratna said, there is an important takeaway when it comes to public health.

“Mitigation of infection risk may be particularly important for cancer patients,” Weeraratna said. Based on the study results, the measures adopted by vulnerable patients from the early days of the pandemic – wearing masks, avoiding crowded places, getting vaccinated – become even more important.

Other studies offer revealing clues about the virus-cancer link.

Pathologists at the University of Arkansas for Medical Sciences reported in 2021 in the journal Communications Biology that SARS-CoV-2 proteins fueled the replication of a herpesvirus considered one of the main viruses leading to cancer . Other studies have implicated the coronavirus in stimulating dormant breast cancer cells.

A 2023 paper published in the journal Biochemistry explored the mechanisms that the coronavirus could exploit to worsen several forms of cancer, including lung, colorectal, pancreatic and oral cancer. The researchers suggested that the most likely route was to disrupt the body’s ability to suppress tumors, but the researchers acknowledged the lack of direct evidence to support this theory.

Wallace believes that the lack of concrete data on coronavirus and cancer reflects political choices more than scientific challenges.

“I would say that most governments do not want to think about long covid and even less about long covid and cancer. It cost them so much to deal with covid. So there is very little funding for the long-term effects of the virus,” he said. “I do not think so…

News Source : www.washingtonpost.com
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