Cancer

 

Cancer begins with changes in one cell or a small group of cells. Cells normally produce signals that will contol how much and how often they will divide to produce new cells. This is controlled by the genes inside the nucleus.

 

If the genes change or mutate, the cells continue to reproduce and form a cellular growth (lump) called a tumour or neoplasm. The damaged or faulty cells no longer have the correct instructions and start to multiply uncontrollably. The tumour then deprives other cells of nutrients. 

 

Tumours can be benign (non-cancerous) or malginant (cancerous).

 

Benign tumours usually grow quite slowly and are covered by a layer of normal cells. They don't spread to other parts of the body and only become life threatening if they grow too large in areas such as the brain.

 

Malignant tumours often grow faster and infiltrate nearby tissues causing damage. They can spread to other parts of the body through the blood and lymphatic system, causing secondary tumors to grow. These secondary tumours are called metastases. The original tumour is known as the primary tumour.

 

Oncology is the study of malignant tumours, otherwise known as cancer. There are five main catagories of cancer, and they are grouped accordint to the type of cell they start in.

 

• Carcinoma – This type of cancer starts in the skin or in tissues that line or cover internal organs. 

• Sarcoma – This type of cancer starts in connective or supporting e.g. bone, cartilage, fat, muscle, or blood vessels

• Leukaemia – This type of cancer begins in tissues, such as bone marrow, that are responsible for making blood.  

• Lymphoma and myeloma – This type of cancer forms in the cells of the immune system 

• Brain and spinal cord cancers – These types of cancers form in the central nervous system