Also on the rise in those aged 40 to 60 are melanomas, lung cancer and prostate cancer, as well as typically rarer cancers such as gallbladder cancer, endometrial (womb) cancer, ovarian cancer and stomach cancer.
Despite all this, “cancer remains primarily a disease of ageing”, says Prof Richard Simcock, the chief medical officer for Macmillan Cancer Support.
“There is still a relatively small proportion of younger people developing cancer,” he explains, but “that rise is still of great concern to us”.
“There isn’t some blockbuster theory as to why this is happening, but we do know broadly how people might hope to lower their risk from cancer if they belong to this age group.”
Here is what you can do to protect yourself from the cancers occurring most commonly in this age group.
Avoid weight gain
It’s no secret that your weight is a big risk factor when it comes to whether you might develop cancer, even if you’re not yet 60.
But what exactly links weight and cancer incidence is not yet clear, Simcock says.
“We don’t know if that heightened risk is because of the weight you’re carrying itself, a lack of exercise, the things you’re eating – there has been much discussion about processed and ultra-processed food – or the other reasons you might be obese, like insulin resistance,” he explains.
With the latter case, “it may be the reason for your obesity, rather than your obesity itself, that is the risk factor in your cancer development,” he adds.
Still, the advice is that those aged between 40 and 60 try to keep their weight within a healthy range to lower the chance that they will develop the disease.
Some research suggested this is particularly important for women who have already gone through menopause.
One study of more than 100,000 women found that even those who lost a small amount of weight – between 2-4.5kg – significantly reduced their breast cancer risk.
Another found that overweight postmenopausal women who lost at least 5% of their overall weight reduced their risk of all weight-related cancers, and especially endometrial cancer, which is on the rise in those under 60 despite a previous decline in older age groups.
Exercise is crucial
Similarly, inactivity could be a major driver in cancer incidence, particularly in rarer cancers where a rise in diagnosis is unexplained, Simcock says.
“Endometrial cancer is more common in women who are overweight or obese,” he says, which again may be a result of lifestyle factors rather than the weight carried itself.
Another major study published this year found that three times as many cancers can be linked to physical inactivity than previously thought; nearly 5% of all diagnoses in Australia – where the research was carried out – were attributable to a lack of exercise.
Of these, nearly 2% could have been prevented if those diagnosed had increased their physical activity by just 40 minutes a week a decade earlier.
Again, it’s difficult to pinpoint exactly why this might be, Simcock notes.
“But whilst this is being investigated and more complex theories are being developed, in the meantime the advice is to be aware of how your lifestyle can increase your risk and take steps to be more active.”
Improve your gut health
“In recent years we’ve really come to understand more about how our microbiome – the bacteria that live in and on us – affect our risk of developing cancer and then how we respond to treatment,” Simcock says.
“We have some really interesting data now to show your microbiome can influence how someone responds to cancer treatment, especially immunotherapy for lung cancer and melanoma,” he explains.
“This treatment seems to work incredibly well for some people but not others, and we now believe that this could be linked to the bacterial contents of your gut.”
Though research is ongoing, this does suggest that keeping a healthy gut could be an important factor in your resilience to cancer.
On the other hand, a separate study published in May this year found that regularly consuming ultra-processed food is linked to higher mortality rates in those with colorectal cancer.
To eat for your gut, try to avoid ultra-processed foods – which contain chemicals that have names you probably won’t recognise – and eat more pre and probiotic foods, such as yoghurt, bananas, oats and beans.
Use sunscreen and stay in the shade
Skin cancers are on the rise in those aged 40 to 60, often because of sun exposure that people in this age group had years or even decades ago.
Non-melanoma skin cancers are common and typically can be treated with relative ease, but melanomas are far more deadly and are on the rise in this age bracket too.
“It’s not uncommon that a sunburn you get now might increase your risk of skin cancer 10 or 15 years later,” Simcock says.
“This rise in cancer might be because of the ease of travel abroad these days, and easier overseas travel, which wasn’t so available to older generations when they were children.”
It is still well worth protecting the DNA in your skin from any further damage, to reduce your melanoma risk. Here the conventional advice stands: use a good SPF to avoid tanning and burning, and stay in the shade when there might be a risk of sunburn.
Cut down on your drinking
High alcohol consumption is a major risk factor associated with oral and stomach cancers, which are on the rise in those aged under 60, as well as with breast cancer in women, Simcock says.
“Every extra unit of alcohol that a woman regularly drinks per week will increase her risk of breast cancer,” he explains. Meanwhile, “alcohol does seem to be linked to the number of cancers we’re seeing in the oesophagus, mouth and stomach”.
This is a particular concern for men, who drink significantly more on average than women.
One 2022 study found that men who drink at least five times a week have at least a 46% higher risk of stomach cancer, even when drinking fewer than five units (around two pints of beer or two glasses of wine) per day.
Men who drink were almost a third more likely to develop stomach cancer than non-drinkers, while no such association was found in women.
Cutting down to one or no drinks on most days could reduce your chances of developing liver cancer by 21% if you currently have four or more drinks per day.
Avoid second-hand smoke
We are all used to hearing that smoking is the single biggest thing we can do to increase our chances of developing cancer. Yet lung cancer is on the rise in people aged 40 to 60, even among those who have never smoked.
One factor may be air pollution, which has become increasingly heavy in recent years, “but there is little that many people living in cities can do about this”, Simcock says.
Data concerning air pollution still remains “controversial”, he says. However, instances of lung cancer as well as breast cancer have been tied to secondhand smoke inhalation. “It’s wise to avoid secondhand smoke as this may help to lower your risk of lung cancer”.