Cancer and carcinogens

• Factors work together and affect physical and mental health
• A disease is a disorder that affects an organism's body, organs, tissues or cells
• Cancer is a disease caused by normal cells changing so that they grow and divide in an uncontrolled way.
• The uncontrolled growth of cancer cells causes a lump called a tumour to form.
• Cancer cells produce a growth called a tumour.
• There are two types of tumour - benign and malignant.
• Benign tumours grow slowly, usually grow within a membrane, so can easily be removed, and do not invade other parts of the body.
• Cancer cells are undifferentiated and do not carry out their normal function.
• Genetic factors increase the likelihood of developing some cancers.
• The likelihood of developing cancer increases as we get older due to the accumulation of mutations.
• Secondary tumours may develop.
• Lifestyle factors that increase the likelihood of developing cancer include viruses linked with cancer, such as the human papilloma virus (HPV), being spread from person to person through sexual intercourse, and chemical carcinogens in cigarette smoke increasing the risk of lung cancer.
• Exposure to chemical carcinogens increases the risk of cancer.
• For cancer to develop, several mutations are required.
• Exposure to ionising radiation increases the risk of cancer.
• Diet, including fat and salt intake, increases the risk of cancer.
• Exposure to ultraviolet A, a high energy part of the electromagnetic spectrum associated with sunburn and skin cancer, and ionising radiation, which is able to remove electrons from atoms or molecules to produce positively charged particles called ions, can lead to the development of skin cancers.
• Carcinogens cause cancer by damaging DNA.
• Alcohol intake is linked with certain cancers.
• Chemicals and other agents that can cause cancer are called carcinogens.
• There are also genetic risk factors for some cancers.
• Mutations are random and spontaneous changes in the structure of a gene, chromosome or number of chromosomes.
• Malignant tumours grow quickly, invade neighbouring tissues and can spread to other parts of the body in the bloodstream, and as the tumour grows, cancer cells detach and can form secondary tumours in other parts of the body - this is called metastasis.