One-in-two men and a third of women are at risk of getting cancer in their lifetime. Although cancer can develop at any age, it mainly affects older people - with more than a third of cancer cases being diagnosed in people aged 75 or older.
See also: Men and cancer - six symptoms you should never ignore
Why age is a risk factor
Up to the age of 50, the risk of developing cancer is 1 in 35 for men and 1 in 20 for women, according to Cancer Research UK. Once we get into middle age, the risk increases considerably. Some 78% of all cancer diagnoses occur in people aged 55 or older, according to the American Cancer Society. If you're wondering, the median age of a cancer diagnosis is 66 years, according to the National Cancer Institute (breast cancer is 61 years, prostate cancer 66 years, bowel cancer 68 years, and lung cancer 70 years).
So why is age such a risk factor? Research is on-going, but experts suggest that increased exposure to carcinogens over time, along with increased oxidative stress, a type of DNA damage caused by free radicals, explains the increased risk.
While we're more prone to develop cancer generally as we get older, age is a particular risk factor for five main types of cancer.
1. Skin cancer
Most cases of skin cancer are caused by over exposure to the sun, so it makes sense that our risk increases the more time our skin has been exposed to sun damage. Both long-term exposure and short periods of overexposure (sun burn) can damage the DNA in our skin cells. Research suggests that skin damage from UV light during childhood doesn't show up until many years later. If you have spent a lot of time outdoors, your skin is naturally fair, or you have used sun beds, you're risk will be greater.
Skin cancer is one of the most common cancers in the UK and cases of melanoma (an aggressive type of skin cancer that can spread to other parts of the body), is on the rise. There are currently around 13,000 new melanoma cases diagnosed each year in the UK – but caught early, it's also one of the most treatable forms of cancer.
As you get older, it's even more important to watch for any changes in the appearance of a mole. A change in the size, shape and colour of a mole or the development of a new mole are warning signs.
See also: Could it be skin cancer? How to tell if a mole is cancerous
2. Breast cancer
Breast cancer is one of the most common cancers in the UK. One-in-eight women will develop breast cancer at some point in their lives – and the majority of cases (81%) are diagnosed in women over the age of 50.
All women in the UK aged 50-70 who are registered with a GP are automatically invited for breast cancer screening every three years. It's important to go along for a mammogram (a special type of x-ray that can detect cancers when they are too small to see or feel) as you stand a much higher chance of recovery if the cancer is detected in its early stages.
As you get older, it's even more important to check the look and feel of your breasts. If you notice anything usual – such as a thickening of the tissue, puckered skin, or a lump, see your GP.
See also: Breast cancer isn't always a lump: seven less-obvious signs to watch for
3. Lung cancer
Lung cancer was the second-leading cause of death in men in the UK in 2013, second only to heart disease, and causes more deaths in both men and women than any other kind of cancer. Two-thirds of people diagnosed with lung cancer are aged 65 or older, which is generally (but not always) caused by smoking or exposure to second hand smoke.
Most people with lung cancer don't experience any symptoms in the early stages of the disease - and even in the later stages, many of the signs are easy to mistake for something else. Common symptoms include a stubborn cough that lasts several weeks, repeated chest infections, and coughing up blood. If you've been a smoker, or smoke now, don't dismiss a persistent cough, see your GP.
See also: Seven surprising lung cancer symptoms
4. Prostate cancer
In the UK, around one-in-eight men will get prostate cancer at some point in their lives. Your risk of prostate cancer increases with age once you reach 50 (men under 50 can get prostate cancer but it's far less common). Most men are aged between 65 and 69 when they are diagnosed.
If you're over 50 and have difficulty urinating, get up often during the night to urinate, or find blood in your urine, see your GP immediately. If you're over 50 and have a higher risk of prostate cancer – because you have a family history or you're black – you might want to talk to your doctor about tests.
Often, early prostate cancers can often be watched and don't progress, but others are more serious and need to be treated.
See also: "Prostate cancer runs in my family but it was still a shock"
5. Bowel cancer
Your chances of developing bowel cancer increases sharply from around the age of 50 to 54 (particularly for men). In the UK, nearly 90% of bowel cancer cases are diagnosed in people over the age of 60. If you have a family history of bowel cancer (your mother, father, brother or sister was diagnosed with bowel cancer below the age of 50) you're at greater risk of developing it yourself.
Lifestyle factors can also increase your chances of developing the disease. For instance, a diet that is high in red or processed meats can increase your risk, and if you are overweight the chances of developing bowel cancer are also higher. Alcohol consumption and smoking also play a part.
In the early stages, bowel cancer is unlikely to cause any symptoms – which is why screening and prevention is so important. If caught early, the survival rate for bowel cancer is 90 percent. If you notice blood in the stools or from the rectum, a persistent change in bowel habits (such as diarrhoea, constipation, or more frequent trips to the toilet) or abdominal pain, get it checked out.