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What is cancer?
Half of us will get cancer at some point in our lives – mostly in old age. But some things increase our risk of cancer. Why is this? Read on to find out more about what causes cancer, how it’s treated, and steps you can take to help prevent it.
What is cancer and what does it do?
Your body is made up of many different types of cells that form your tissues and organs. These cells normally divide in a controlled way to grow and repair tissues.
But cancer cells behave differently to normal cells. They grow in an uncontrolled way and don’t repair themselves if they become damaged. This means they keep dividing when they shouldn’t, often forming a lump of cells called a tumour. Cancer can start almost anywhere in your body, and there are more than 200 different types of cancer.
Cancer can affect your body in different ways. Tumours can press on or block organs, or affect how they function. Cancer cells can also spread (metastasise) to another part of your body. But tumours aren’t always cancerous – benign tumours don’t metastasise, and they grow more slowly than cancerous (malignant) tumours.
What are the types of cancer?
Cancers are named after the types of cells they develop from. Below are the five main cancer types.
- Carcinomas. These are cancers that starts in epithelial tissues, which include the skin and the tissues that cover internal organs. The most common type of cancer in the UK is carcinoma: 85 out of every 100 cancers are carcinomas.
- Sarcomas. These are cancers of connective tissues, like bone and cartilage. They are relatively rare, with fewer than 1 in every 100 cancers being sarcomas.
- Leukaemia. This cancer affects the blood cells in the bone marrow, usually white blood cells. Leukaemias are the most common cancers in children.
- Lymphoma and myeloma. These cancers affect the lymphatic system, which is part of the immune system and helps to fight infection.
- Central nervous system cancers. These include cancers of the brain and spinal cord.
Common carcinomas include cancers of the breast, lung, prostate, and bowel. Together, these four cancers alone make up over half of all new cancers diagnosed in the UK.
What are the symptoms of cancer?
Cancer symptoms vary depending on the type of cancer, but there are certain symptoms to look out for such as:
- a new lump in any area of your body, for example a breast lump or testicular lump
- unusual bleeding, such as in pee, vomit, or poo (stool), and vaginal bleeding between periods or after sex
- unexplained weight loss
- fatigue
- very heavy night sweats or fevers
- a change in bowel habits
Symptoms can differ between people, and symptoms like these can also be caused by other medical conditions. But diagnosing cancer early can make a big difference to how well it can be treated. So if you ever notice any symptoms like these, or an unusual change that doesn’t go away, speak to your GP.
How is cancer diagnosed?
Cancer can be diagnosed based on your symptoms, from a biopsy, or from cancer screening.
If you have symptoms that could be caused by cancer, speak to your GP about them. Your GP may ask about your family history of cancer, as this can affect your risk of some cancers. You might also need tests, such as blood tests or an ultrasound scan, to figure out what’s causing your symptoms.
Your GP can refer you to a specialist if they think your symptoms may be caused by cancer. They may do a biopsy (a procedure that removes a small sample of tissue) to check if an unusual lump is cancerous (malignant) or not.
Cancer screening is normally offered to adults once they reach a certain age, depending on which part of the country they live in. It aims to identify cancer earlier, when treatment is often most effective.
In the UK, the three cancer screening programmes are:
- breast cancer screening
- bowel cancer screening
- cervical screening
Cancer prevention: awareness and screening
Checking for signs of cancer | Cancer screening programmes | Watch in 5:53 minutes
This Bupa animation will show some simple checks you can do at home and explains what cancer screening programmes are available in the UK.
How is cancer treated?
Different types of cancer respond to different treatments. Cancer treatment also depends on how far the cancer has grown and if it’s spread. Treatments for cancer include:
- surgery – for example, to remove a tumour
- chemotherapy – this uses medicines to kill cancer cells
- radiotherapy – this involves high doses of radiation to kill cancer cells
- immunotherapy – using the immune system to fight cancer
Lots of cancers can be cured, but some can come back years later. So, doctors sometimes say that cancer is in remission instead. This means that there are no obvious signs of cancer at that time.
Everyone is different, and several things affect whether a cure is possible. For example, the type of cancer, where it is, how far it has grown or spread, and how well treatment is working.
What causes cancer and how can cancer be prevented?
Cancer isn’t contagious, which means you can’t catch it from other people. But there are several factors that increase your risk of getting cancer, such as your lifestyle and environment.
Age is the biggest single risk factor – more than a third of newly diagnosed cancers are in people aged 75 or older. You might also inherit genes that increase your risk of certain cancers, including breast, bowel, and ovarian cancers.
Although not all cancers are preventable, around four in 10 cancers could be prevented by making lifestyle changes. This is because they’re caused by risk factors such as the ones below that you can limit or change.
- Tobacco. Smoking is the main cause of lung cancer, but it also increases risk of other cancers, including cancers of the bladder, bowel, pancreas, stomach, and oesophagus. Smoking is also the leading preventable cause of cancer, both in the UK and globally.
- Your weight. Being overweight or obese is the second main cause of cancer in the UK, second only to smoking. It increases the risk of several cancers, including breast, bowel, kidney, and oesophageal cancer.
- Alcohol. Drinking alcohol increases your risk of mouth and throat cancer, as well as cancers of the oesophagus, bowel, liver, and breast. And the more alcohol you drink, the higher your risk of cancer, as well as other health problems.
- Diet. Processed meat – such as bacon, sausages, or preserved meat such as salami - can cause bowel cancer. A diet high in red meat, such as beef, pork, and lamb, could increase your risk of cancer, too. Try to eat a well-balanced diet, including five portions of fruit and vegetables each day. This is not only good for your overall health, but it can help you maintain a healthy weight and lower your risk of cancer. Eating lots of fibre and wholegrains can also reduce your risk of bowel cancer.
- Infections. Some infections increase your cancer risk. For example, a virus called human papilloma virus (HPV) can cause cervical cancer, and it’s also been linked with mouth and genital cancers.
- Lack of physical activity. Regular exercise can reduce your cancer risk in several ways. Physical activity boosts your immune system, lowers stress, and helps you keep a healthy weight. People who are physically active have a lower risk of breast and bowel cancer.
- Sun and sunbeds. Ultraviolet (UV) rays can burn your skin, which increases the risk of skin cancer, including melanoma. Using sunscreen and covering up can help keep you safe in the sun, protect your skin from sunburn, and reduce your risk of skin cancer.
By making lifestyle changes, you can help lower your risk of cancer. If you’d like to know more about your cancer risk, why not try our cancer risk quiz?
Nobody likes to think about being diagnosed with cancer. But our health insurance gives you personal cancer care with support at every stage of your treatment for as long as you have a policy with us. Learn more about our health insurance.
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