cancer

• benign tumours are growths of abnormal cells which are found in one area
• benign tumours are usually contained within a membrane
• malignant cells invade neighbouring tissue and move into the bloodstream
• once in the bloodstream, malignant cells can spread to different parts of the body and form new tumours
• smoking: lung cancer
• ultraviolet light: skin cancer
• alcohol: mouth and throat cancer
• mutations in the BRCA genes have been linked to an increased likelihood of developing breast and ovarian cancer