Cancer is a generic term for a large group of diseases that can affect any part of the body, characterised by the uncontrolled growth and spread of abnormal cells. These abnormal cells form tumours or invade surrounding tissues, disrupting the normal functioning of organs and systems.
Cancer is a significant public health issue and is a leading cause of death worldwide, accounting for nearly 10 million deaths in 2020, or nearly one in six deaths. There are various types of cancer, each with its unique characteristics and treatment options – the most common types include breast cancer, lung cancer, prostate cancer, colorectal cancer and skin cancer, among others.
The risk factors
Between 30 and 50% of cancers can currently be prevented by avoiding risk factors and implementing existing evidence-based prevention strategies.
Cancer development is influenced by a combination of genetic, environmental and lifestyle factors. While some risk factors are completely uncontrollable, such as age and family history, many others can be addressed to reduce the risk of developing cancer.
General risk factors for cancer include the following:
Age – the risk of developing cancer increases as you get older.
Lifestyle factors – these include smoking, your weight, your diet, how active you are, sun exposure and sunbed use and how much alcohol you drink.
Family history – some cancers are more common in some families.
Lifestyle risk factors and reducing your risk
Giving up smoking
Smoking is the biggest cause of cancer in the UK. It causes 15 in every 100 cancers and over 70 in 100 lung cancers are caused by smoking. Giving up smoking is the single most important thing you can do for your health.
Limit how much alcohol you drink
Drinking alcohol increases your risk of mouth and throat cancers. It is also linked to cancers of the gullet (oesophagus), bowel, liver and breast. There is no safe level of drinking alcohol but sticking to the recommended guidelines reduces the risk of damaging your health.
Keep to a healthy weight
After smoking, being overweight is the second biggest cause of cancer. It increases the risk of many cancer types, including cancers of the bowel, kidney, womb, and gullet (oesophagus).
Excessive adipose (fat) tissue can create environments where cancer cells can thrive, due to chronic inflammation, hormone imbalance and impaired function, as well as suppression of the immune system.
Eat a healthy diet
There is no single food that causes or prevents cancer but try to limit how much red and processed meat you eat as these are linked to a higher risk of bowel and prostate cancer.
Be physically active
Lack of regular physical activity is associated with a higher risk of certain cancers, primarily due to the increased risk of becoming overweight.
Take care in the sun
Spending some time outside helps you stay healthy as our bodies need sunlight to make vitamin D, but it is important to protect your skin from too much sun. This is because too much sun can increase your risk of skin cancer. Using sunbeds or sunlamps also increases your risk of skin cancer.
Workplace and environmental factors
Exposure to certain chemicals, radiation and carcinogens in the workplace or environment can increase cancer risk.
A small number of viruses have been linked to a higher risk of certain types of cancer. These viruses include:
Human papilloma virus (HPV), which increases the risk of cervical cancer and is linked to cancers of the head and neck, anus, vulva, vagina and penis;
Hepatitis B and C, which are linked to liver cancer;
HIV, which can increase the risk of cancers including lymphoma and sarcoma.
The cancer burden can also be reduced through early detection of cancer and appropriate treatment and care of patients who develop cancer. Many cancers have a high chance of cure if diagnosed early and treated appropriately.
It is essential to remember that having one or more risk factors does not guarantee that an individual will develop cancer, and vice versa—some individuals without any apparent risk factors may still develop cancer. If an individual is living with several uncontrollable risk factors, it is important to moderate risk by living a healthy lifestyle, in combination with regular health screenings and early detection.