Cancer increase in the young: If Covid is to blame and how to reduce your risks

For example in my list of patients last week, there were 10 patients under 40 and 3 under 30 years of age. Thinking back 10 years ago, I rarely saw anyone under 40 years but now this seems to be the norm. As well as distressing for those affected, this trend is having significant logistical implications for cancer services as younger patients present particular challenges.

Cancers in young people (usually defined as under 50 years) are often picked up later at a more advanced stage. They also tend to be of more aggressive types so patients are more likely to need complex, multidisciplinary surgical, radiotherapeutic and medical management including intensive, prolonged chemotherapy and biological therapies.

Other issues such as coping with young children, relationships, preserving fertility, and financial security are more relevant in the young.

I particularly remember a 29 year old girl who was squeezed into the end of an evening clinic which highlights many of issues of young people. She had jaundice and multiple organ failure because so much cancer had spread to her liver from an undetected bowel cancer.

She had complained of colicky symptoms for six months but being young this was put down to an irritable bowel. If older, she would have been investigated earlier. Likewise, if over 50 years she would have undergone bowel screening and the cancer picked up even earlier.

With such advanced disease, she had already been told that treatment, if any, would be palliative, but after explaining the risks, we decided to try some oral chemotherapy. To preserve her ovaries we gave some injections which made her temporarily post-menopausal although there was no time for egg preservation which is the most reliable way to maintain the option of children later.

With incredible resilience, determination and courage on her part, we managed to increase the dose of chemotherapy gradually over several months as her liver function improved. We were then able to add more intensive biological and intravenous treatments.

After a year, the local surgeon was able to cut out the primary cancer in the bowel and later a specialist liver surgeon managed to resect (cut out) half the liver metastasis (the spread of cancer cells from the place where they first formed to another part of the body). Further chemotherapy shrunk the remaining disease and as the liver has a remarkable ability to regenerated (like a newts tail) the surgeon was then able cut out the remaining cancer.

Not surprisingly, however, six months later a scan showed her cancer had spread to her lungs. Fortunately these deposits were successfully resected by a team of specialist thoracic surgeons. Following yet further biological treatments all the known disease was finally cleared - a pathway which look over two-and-a-half years. She has now gone on to gain a PhD in cancer science and have two healthy children.

To check whether the increase in young patients with cancer was genuine and when the trend started, we conducted an audit looking at the ages of new cases over the last 20 years for all oncologists in our region. In line with international findings, we found that rates under 50 years and even more so under 40 had significantly increased particularly for bowel, ovary and breast cancer.

The exact cause of the increase in cancer in young people has not yet been confirmed. Some people have suggested it was somehow connected to covid. Despite the popularity of this theory, no robust associations have been found with the virus or the vaccine but the social isolation certainly could have been a contributory factor.

The lack of interaction with other people, together with excess cleaning meant the immunity was underchallenged during this time potentially downgrading its function. The immune system, as well as fighting infection, protects us from cancer by recognising early cancer cells and killing them.

There is some rationale for this immune theory from previous observational studies. For example, children born by caesarean section, not exposed to the bacteria in the mother's faeces, are reported to have higher rates of immune disfunction. A study published in the prestigious Nature Journal found that, apart from genetics, the strongest risk factor for the development of childhood leukaemia was "overclean kids" especially in the first two years of life.

These data leads us to the strongest hypothesis that changes in the bacteria on and within our bodies (our microbiome) are contributing to the increase in cancer in younger people. It is already known that overgrowth of less favourable bacteria in the gut leads to local inflammation, reduced immune surveillance and impaired gut integrity.

Toxins leaking into the body then triggers a general inflammation. Inflammation causes cells to grow faster leading to more spontaneous mutations and less time for cells to repair themselves - the origins of cancer. The combination of higher chronic inflammation and reduced immunity is particularly concerning.

Not surprisingly numerous studies from across the World are now linking a poor gut health and alterations in the microbiome with higher rates of cancer, not just for bowel but ovary and breast cancers. Although, other factors such as pollution, oestrogenic plastics, ultra-processed foods and sedentary behaviour are clearly influential, it would be very sensible to adopt strategies to improve the quality of our microbiome. These include:

• Avoiding habits which damage healthy bacteria such as smoking, having a high meat low plant based diet, drinking excess alcohol, not exercising and consuming too much processed sugar or artificial sweeteners.
• Eating more foods which contain healthy probiotic bacteria such as fermented and pickled foods; live yoghurt, kefir, aged cheeses, miso soup, tempeh, kimchi, natto and sauerkraut.
• Eating more foods rich in soluble fermentable fibres and phytochemicals which act as prebiotic that support the growth of the healthy bacteria such as: chicory, leeks, asparagus, onions garlic, nuts linseeds, beans fruit and vegetables.

In conclusion, although more research is needed, even with existing evidence, adopting a diet and lifestyle which enhances gut health and the whole body microbiome is very likely to reduce cancer risks, especially in the young. In addition to heightening public health awareness, scientific studies are investigating the role for boosting the diet with probiotic supplements especially for people who find it hard to adopt these lifestyle measures or populations such as the UK which do not traditionally eat a lot of fermented bacteria rich foods.

One lactobacillus / chicory / vitamin D supplement, in particular, is undergoing extensive scientific evaluation. It has already demonstrated significant benefits for people with long covid and is the chosen blend for the ongoing national covid vaccine enhancement study and a national gut health and cancer intervention study. If the results of this trial are positive it will encourage significant interest in further microbiome enhancing strategies for cancer prevention and cancer treatment support.