Cancer also termed as malignancy, is an uncontrolled growth of abnormal cells anywhere in the body. There are more than 200 different types of cancer, including lung cancer, colon cancer, prostate cancer, and lymphoma, just to name a few. All these cancer varieties result in cell growth in an abnormal proportion in the respective parts of the body, and the condition may eventually spread into other tissues through blood and lymph vessels.
Cancer refers to cells that grow enormously and attack other tissues. Popularly known as malignant or tumor cells, these abnormal cells infiltrate normal body tissues.
Due to the uncontrolled growth and division of the abnormal cells, a mass forms. Quite often, these cancer cells can break away from this mass of cells and lodge in the other parts of the body by traversing through the blood and lymph systems. This may cause an uncontrolled growth cycle to begin away from the site of origin, spreading throughout the body and spreading uncontrollably leading eventually to individual's death. This process, wherein the abnormality develops leading to a malignant growth (secondary) at a distance from a primary site of cancer, is called as metastasis.