Health and lifestyle
More than 1 in 3 people in the UK will get cancer during their lives. Everyone has a certain risk of developing cancer. It’s thought that this is affected by a combination of our genes, lifestyle and environment.
Most of the time, we don’t know exactly what causes any particular cancer. But we do know some of the risk factors for cancer. Risk factors are things that can make you more likely to develop cancer. They include things such as being older, smoking and being overweight.
Some risk factors are very likely to cause cancer. Others only slightly increase the risk of getting it. Usually, cancer is the result of a combination of several risk factors.
Having a particular risk factor doesn’t mean that you’ll definitely get cancer - just as not having any risk factors doesn’t mean you won’t.
Smoking is a good example of this. If you smoke, it isn’t certain that you will get lung cancer - just as if you don’t smoke, it’s not certain that you won’t. But smoking will greatly increase your risk of getting lung cancer. About 9 out of 10 people who develop lung cancer are smokers.
For most people, increasing age is the biggest risk factor for developing cancer. In general, older people (those over 65) are far more likely to develop cancer than younger people (those under 50).
Cancer is very common. Most of us have relatives who’ve had cancer. People often worry that a history of cancer in their family greatly increases their risk of developing it. But in fact, fewer than 1 in 10 cancers (5-10%) are associated with a strong family history of cancer.
How does family history affect cancer risk?
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Most cancers aren’t caused by inherited cancer genes. If one or two of your relatives have had cancer, this doesn’t necessarily mean there is a cancer gene in your family.
In general, the more members of your family who have been diagnosed with the same type of cancer, and the younger they were when diagnosed, the more likely it is that there’s a family link.
It’s only likely that a cancer gene may be present in your family if:
One of your first-degree relatives has had two different types of cancer (this means they’ve had two separate cancers, not one cancer that spread somewhere else). First-degree relatives are your parents, children, brothers and sisters.
Two or more closely related people in your family have had the same type of cancer, or have had types of cancer that are sometimes connected (breast cancer and ovarian cancer are sometimes connected, and so are bowel cancer and womb cancer).
Members of your family have had cancer at an unusually young age (for example, bowel or breast cancer under the age of 40).
If you’re worried about a history of cancer in your family, talk to your GP. They may be able to reassure you or refer you to a clinical genetics service or family cancer clinic.
People with a strong family history of some types of cancer (bowel or breast cancer) are offered earlier or more frequent screening than other people. Screening is explained below.
There are tests for changes (alterations) in genes that increase the risk of getting breast, ovarian or bowel cancer, as well as some rarer cancers.
If you have a strong family history of one of these cancers, you may be offered a test to check if there is an inherited cancer gene in your family. Genetic testing is normally only possible if you have a relative with one of these cancers who is willing to be tested first.
There's more information in our cancer genetics section. We also have more specific information about genetics if you're worried about:
Risk factors other than family history often play a more important role in the development of cancer. We know that many cancers could be prevented by lifestyle changes. Up to 40% of cancers in the UK could be prevented by lifestyle changes.
Making these changes doesn’t guarantee that you won’t get cancer, but they will make it less likely and will improve your health generally.
Give up smoking
Smoking is the single biggest avoidable cause of cancer. If you smoke, giving up is the most important thing you can do for your health.
In the UK, about 1 in 5 cancers (19%) and more than 1 in 4 cancer deaths (about 29%) are caused by smoking. It increases the risk of many cancers including cancers of the mouth, throat, lung, bladder, kidney, pancreas, bowel, stomach and cervix.
Breathing in other people’s smoke (passive smoking) also increases your risk of developing cancer.
Help is available if you want to give up smoking. Ask your GP for advice, or contact your national stop smoking service.
Tel 0800 022 4332
(Mon-Fri, 9am-8pm, Sat-Sun, 11am-4pm)
Tel 0800 84 84 84
Stop Smoking Wales (Wales)
Tel 0800 085 2219
Smokers’ Helpline (Northern Ireland)
Tel 0808 812 8008
Keep to a healthy weight
The latest figures for the UK estimate that more than half of adults (61%) are overweight.
Being overweight increases the risk of several cancers including cancers of the pancreas, bowel, womb (uterus) and kidney, as well as breast cancer after the menopause. It can also lead to problems such as heart disease, high blood pressure or diabetes.
If you’re overweight, getting back to a healthy weight is one of the best ways to reduce your risk of cancer.
Your GP can advise you on the ideal weight for your height. The best way to lose weight is through a combination of eating a balanced diet and being more physically active.
Eat a healthy diet
A healthy diet can reduce your risk of cancer, particularly bowel cancer.
You should eat foods high in fibre, such as beans, oatmeal, fruit and vegetables. Aim to eat five portions of fruit and vegetables every day.
Limiting how much red meat, salt and processed meat you eat is also important. Processed meats are meats that have had preservatives added or that have been preserved by salting, curing or smoking. They include sausages, ham and burgers.
Limit how much alcohol you drink
Drinking alcohol, especially drinking more than the recommended limits, increases cancer risk. About 4 in 100 cancers in the UK (4%) are linked to alcohol.
Alcohol especially increases the risk of cancers of the mouth and throat. It is also linked to cancers of the bowel, liver and breast. In general, the more you drink the more your risk increases.
The European Code Against Cancer recommends that to reduce cancer risk, men should drink no more than two units of alcohol a day and women no more than one unit a day.
A unit is half a pint of ordinary strength beer, lager or cider, one small glass (125ml) of wine or a single measure (25ml) of spirits.
Keep physically active
Many studies have found that regular physical activity can reduce the risk of cancer. Lack of physical activity increases the risk of bowel cancer, womb cancer and post-menopausal breast cancer. It may also increase the risk of other cancers, such as lung cancer and prostate cancer.
Being physically active doesn’t necessarily mean going to the gym - regular walking, cycling or swimming can be enough.
Try to do at least 2½ hours of moderateintensity physical activity a week. This could be made up of 30 minutes of activity each day for five days. You could even break it up further into 10 minutes of activity, three times a day.
During moderate-intensity activity, you’re still able to talk, but your breathing is quicker and deeper. Your body is warming up, your face may have a healthy glow and your heart is beating faster than normal but not racing.
If you’re not used to exercise, your GP can advise you on getting started.
Take care in the sun
Spending some time outside in the sun helps you stay healthy, but it’s also important to protect your skin from burning, as this can increase your risk of skin cancers.
Our bodies use the UVB rays in sunlight to make vitamin D, which is important for bone health and reduces the risk of many illnesses, including cancer.
Most people can get enough exposure to UVB rays by going outside regularly, without sunscreen on, for a few minutes during the middle of the day. The amount of sun exposure you need depends on your hair and skin type. But it’s important not to stay out long enough to let your skin redden or burn.
If you’re going to be out in the sun for longer than a few minutes, use a suncream that protects against both UVA and UVB rays, with a sun protection factor (SPF) of at least 30.
You should wear loose, cotton clothes that cover your body, as well as a hat. Take extra care with children. Avoid using a sun bed or sun lamp. If you want to look tanned, use fake tanning lotions or sprays.
Have safe sex
Viruses play a role in the development of some types of cancer. Generally, these viruses are sexually transmitted, but some of them can also be transmitted through blood (for example, if drug users share a needle).
Human papillomavirus (HPV) plays a role in many cases of cervical cancer, and it also increases the risk of developing head and neck cancers, anal cancers and cancers of the vulva or penis.
Hepatitis B and C can increase the risk of liver cancer, and the HIV (Aids) virus can increase the risk of developing lymphoma and sarcoma, although this is rare.
Practising safer sex by using condoms or other barrier methods of contraception, and not sharing needles if you use them, can help protect you from contracting these viruses.
Know your body
If you know your body and what’s normal for you, it will help you to be aware of any changes.
People (particularly older people) sometimes think a change in their body isn’t worth bothering their doctor about. But if you notice a change in how you feel or how your body works, and you’re not sure why it’s happened, it’s better to be safe and get it checked out.
You should go to see your doctor if you have:
a lump anywhere on your body
a sore or ulcer that doesn’t heal within a few weeks
a mole that changes shape, size or colour, or bleeds
a cough or hoarse voice that lasts for more than three weeks
shortness of breath
loss of appetite, ongoing indigestion or difficulty swallowing
a change in bowel habit that lasts for more than two weeks
blood in your urine, bowel motions, spit or vomit, or abnormal bleeding from your vagina
unexplained weight loss or tiredness
an unexplained ache or pain that last for more than four weeks.*
Most of the time these changes aren’t due to cancer. But if you do develop cancer, finding it early can make a big difference to how successful treatment is. See your GP if you have any unexplained or ongoing changes in your body.
*Source: The European Code Against Cancer
Screening tests aim to detect cancer early, when treatment is most effective.
In the UK, there are screening programmes for bowel cancer, breast cancer and cervical cancer. If you’re registered with a GP, you should automatically be invited to screening when you reach the age each screening programme starts.
Finding cancer early can make a big difference to the success of treatment.
There’s more information about the screening programmes on these websites:
www.cancerscreening.hscni.net (Northern Ireland)
If you are still worried
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A common reaction to serious illness in the family, or to bereavement, is to feel more vulnerable to the same disease. If you can’t stop worrying, you may find it helpful to speak to a counsellor. You can ask your GP for details of a local counselling service, or contact our cancer support specialists.
The mental health charity MIND has a leaflet called How to Stop Worrying. Order a copy from their website or by calling 0300 123 3393.
Get advice about eating healthily from our Macmillan dietitian, Helen.