Cancer and its risk factors

In a nutshell

Cancer is a disease caused by uncontrolled cell growth and division. There are certain risk factors that can increase the risk of developing some cancers.

Cancer

Cancer is a disease in which changes in some of the body's cells can result in uncontrolled growth and division. This leads to a mass of abnormal cells, also known as a tumour. There are two types of tumours: begin and malignant.

Benign tumours	Malignant tumours
Stay in one location	Spread to other parts of the body by breaking off and travelling in the bloodstream.
Do not invade other body parts	Can invade healthy tissues and form secondary tumours.
Not dangerous or cancerous	Dangerous and can be fatal. These are cancers.

Risk factors

Over the years, research has identified many factors that increase the risk for certain cancers. These include both genetic and lifestyle factors.

Lifestyle risk factors

Smoking	Cigarette smoke is linked to many cancers, including cancers of the lungs, mouth and throat.
Obesity	Being obese can put people at risk of over twelve different types of cancer.
Viral infection	Getting infected by certain viruses can increase the chance of some cancers. Example HPV virus
UV exposure	Exposure to UV radiation (which is produced by the sun) has been linked to developing skin cancer.

Genetic risk factors

Parents pass on their genes to their offspring. Occasionally, an individual may inherit faulty genes. These genes increase the risk of developing cancer.

Example

Inheriting a mutation in the $BRCA1$ gene can increase a person's risk of developing breast cancer.

Improvements in cancer treatment

Nowadays, people have a greater chance of surviving cancer. This is due to an improvement in treatments, the ability of doctors to diagnose cancer earlier, increased screening for cancer, and a greater awareness of the risk factors for cancer amongst the general population.