Scientists studying a rise in rare and unusual cancers in young people are turning their attention to an unlikely culprit: Covid.
Preliminary research on cells has indicated the virus may fuel the growth of tumors and shut down the body’s defense against them – but the theory is widely disputed.
There is, however a consensus among doctors: they’re seeing more young and relatively healthy people with obscure forms of the disease after the pandemic.
One doctor told DailyMail.com the theory that Covid is driving these cases doesn’t hold up because the trend predates the outbreak. Early-onset cancers of all forms have been on the rise, increasing by 79 percent from 1990 to 2019 globally, according to an analysis published in BMJ Oncology last year.
Others found the Covid theory more convincing. They pointed to the fact that already one in four cancer have been linked to other viruses, such as HPV.
The above graph shows the change in cancer case rates around the world
Kasra Jahankhani, an Iranian immunologist and lead researcher on a 2023 report on the topic told DailyMail.com: ‘It’s really controversial and there is a lot of debate around the topic, but we think there are many ways SARs Covid infection could affect cancers.’
His research suggested that the coronavirus can change genes that usually stop tumors from forming and cause widespread inflammation throughout the body.
This inflammation in combination with reduced defenses might lead to the development of cancer cells in various organs, they wrote.
Viral associations with cancers are ‘unfortunately common,’ said Dr Landau, oncologist and contributor for The Mesothelioma Center at Asbestos.com.
With the human papilloma virus (HPV), for example, it is believed that the virus itself can inject its DNA into the body’s cells, which can cause a mutation that leads to growth of cancerous cells.
‘Essentially, the virus is trying to take over our body’s cells to promote its own growth and survival.
‘But mutating cells to continuously grow is, at a simple level, how cancers develop,’ Dr Landau told DailyMail.com.
However, not all experts are in agreement. Dr Suneel Kamath, an oncologist at the Cleveland Clinic, ruled out a link between Covid and cancer.
‘The trends in rising incidence of cancer in younger people, such as bile duct, colorectal, breast, lung and gastric, have been happening for years, even decades before Covid-19 existed, and they are still happening,’ he told DailyMail.com.
Viral associations with cancers are ‘unfortunately common,’ said Dr Landau, oncologist and contributor for The Mesothelioma Center at Asbestos.com
Research has suggested that the coronavirus can change genes that usually stop tumors from forming and cause widespread inflammation throughout the body
Colon cancer diagnoses in particular among under-50s have reached epidemic levels. Nearly 18,000 cases are diagnosed among this age group every year in the US compared to 12,000 a year pre-2000.
Colon cancer deaths among young people are also expected to double by 2030, experts have warned.
Uterine cancer has also risen two percent each year in people under 50 since the mid-1990s.
Early-onset breast cancer has also increased by 3.8 percent annually between 2016-2019, and cancer rates do not appear to have sped up dramatically since Covid.
But experts have said that it might be too early to see that impact, as ‘the long term implications of the pandemic will evolve over time,’ Dr Landau said.
CDC data shows that more people are being told they have cancer now than they were prior to the pandemic. In 2021, 9.8 percent of adults reported having ever been told by a doctor that they had cancer. In 2019, that proportion of adults was 9.5 percent.
One of the possible links between Covid and cancer is a gene called P53, which suppresses cancerous tumors in the body by stopping cells with mutated or damaged DNA from dividing, Jahankhani explained.
His research team found that the tumor suppressor gene P53 may be ‘degraded’ by SARS-CoV-2 and effectively blocked.
This means it can no longer stop tumors growing. Other research has found that lower levels of P53 can make people more susceptible to cancer.
Another factor involves the renin-angiotensin-aldosterone system (RAAS), which is a key system that regulates blood pressure in the body.
When the SARS-CoV-2 virus binds to ACE2 receptor, it stops the RAAS from functioning properly.
This in turn causes inflammation and oxidative stress, which are factors in cancer progression and development.
Another way Covid and cancer might be linked is by proteins called cytokines.
When the body gets an infection such as Covid, the immune system will begin to fight it off, including using cytokines as a defense system against the virus.
The photo shows the coronavirus indicated in yellow, emerging from the surface of cells, indicated in blue/pink, cultured in a laboratory. Research suggests that the virus can reawaken dormant cancer cells, and cause whole body inflammation that can lead to the proliferation of cancer cells
The proteins tell immune cells what to do and also tell the body to produce more of them to ensure a knockout blow is delivered to the infection.
But sometimes too many cytokines can be released, which puts the immune system into overdrive and creates a heightened inflammatory response.
The release of cytokines is often what makes us feel sick when we have an infection, Dr Landau said.
‘But these same cytokines can cause harm to the body, and that harm can increase cancer risk, especially if they remain elevated in the long term,’ he said.
This heightened inflammatory response occurs with long Covid, he added.
Too much inflammation can damage tissues and DNA and has been linked to the development of autoimmune conditions, as well as cancer.
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Inflammation also causes changes to chromosomes in cells, and repeated changes can cause cells to become cancerous.
This abundance of cytokines can also lead to the emergence of cancer stem cells in organs like the lungs and pancreas, as well as bile ducts.
Because Covid infection occurs directly and indirectly in several organs, including the lungs, brain and kidneys, the researchers believe cancer stem cells can develop in multiple organs.
Stem cells are cells that have the ability the develop into many different cell types in the body.
Cancer stem cells, meanwhile, occur in tumors and have the ability to divide and renew, which grows and spreads the tumor.
They can originate from adult tissue stem cells and initiate a tumor, particularly if there is lots of inflammation from Covid.
And while researchers cannot definitively rule out the Covid vaccines as playing a role, Jahankhani said there is no evidence that this is the case.
His team ‘didn’t find anything’ to support the idea that the Covid shot drove up cancer rates.
The evidence supporting the virus theory appears to be much stronger, he added.
Dr Landau acknowledged that although there have been blood clot issues after the Covid vaccine, ‘a clear link with development of cancer is not yet known.’
‘We suspect the cancer risk would come from the virus itself, rather than the vaccine, but it will take years of follow up studies to truly understand this,’ he said.