Cancer is a broad term for a family of diseases that can strike any part of the body and that result from the abnormal growth of cells. Cancer cells provide no positive function for the body while impeding normal bodily function and ignoring chemical signals from healthy cells. The disease typically first appears as an abnormal mass called a tumor. Cancerous tumors are referred to as malignant, while benign tumors cause no serious harm. Tumors do not appear in cancers such as leukemia, a cancer of the blood cells. Cancer can spread to other parts of the body in a process known as metastasis.
According to the World Health Organization (WHO), cancer is one of the leading causes of...