Cancer and cardiovascular disease - non-communicable
The chance of developing a non-communicable disease can be increased or decreased depending upon a person’s lifestyle or the genes they inherit. Two common types are cancer & cardiovascular disease.
Cancer and carcinogens
Cancer
When a person is growing or replacing old and damaged cells, new cells are produced by mitosis.
Sometimes, cells begin to divide uncontrollably. New cells are produced – even if the body does not need them. This produces a growth called a tumour.
Types of tumour
There are two types of tumour – benign and malignant:
| Type of tumour | Characteristics |
|---|---|
| Benign | Normally grow slowly |
| Benign | Usually grow within a membrane, so can easily be removed and in most cases do not grow back |
| Benign | Do not spread to other parts of the body |
| Benign | Can still be life-threatening if they cause damage to an organ |
| Malignant | Are cancerous |
| Malignant | Normally grow quickly |
| Malignant | Can spread to other parts of the body in the bloodstream |
| Malignant | As the tumour grows, cancer cells detach and can form secondary tumours in other parts of the body - this is called metastasis |
The diagrams shows how cancer cells can invade surrounding tissue:
What causes cancer?
Something that increases the likelihood of developing a disease is called a risk factor. Chemicals and other agents that can cause cancer are called carcinogens.
Carcinogens cause cancer by damaging DNA. Carcinogens increase the chance that mutations will occur. A single mutation will not cause cancer – several are required. For this reason, we are more likely to develop cancer as we get older. There are several risk factors for various types of cancers.
Genetic factors
There are genetic risk factors that increase the likelihood of developing some cancers. For example, inheriting a mutation in the BRCA1 gene can increase a person's risk of developing breast cancer.
Lifestyle factors
- Viruses linked with cancer, such as the human papilloma virus (HPV), being spread from person to person through sexual intercourse.
- The chemical carcinogens in cigarette smoke increasing the risk of lung cancer.
- Alcohol intake is linked with certain cancers, such as liver cancer.
- Exposure to ultraviolet radiation, part of which is ionising, during sunbathing or outdoor activities, leading to the development of skin cancers.
- Diet, including fat and salt intake, increases the risk of cancer.
Industrial and environmental factors
- Exposure to ionising radiation such as UV radiation from sunlight.
- Exposure to chemical carcinogens. An example is asbestos.