Oncology is that part of medical science which is concerned with the management of malignant disease such as cancer.
Cancer is a general term applied to tumours and growths. Body cells normally regenerate and die off continually so the number of cells remain constant. When cells become cancerous, there is an abnormal and uncontrolled increase in the growth rate which results in a mass or tumour growth. The tumour may be benign or malignant.
Benign tumours grow slowly and do not recur after excision but can still be life-threatening if untreated as they can affect vital organs but are usually curable, (cure is generally defined as being free from cancer for 5 years.)
Malignant tumours can infiltrate and destroy the normal tissues surrounding them and spread to other sites.
Metastases occur when the primary tumour spreads either by invading surrounding cells, via the blood stream or lymphatic system. These deposits are referred to as secondaries or metastases. Cure is extremely unlikely once this spread has occurred.
