Cancer is the uncontrolled growth of abnormal cells in the body. The cells become abnormal due to environmental stimuli (e.g., smoking, irradiation, excessive exposure to ultraviolet light, toxins, hormonal imbalances, etc.). These stimuli cause mutations in the genetic make-up of cells. Cancer develops when the body’s normal control mechanisms do not kill these cancer cells. Cells do not die and instead grow out of control forming new abnormal cells. These extra cells may form a mass of tissue, called a tumor.
Some cancers, such as leukemia, do not form tumors. The numbers below describe the estimated number of cancer deaths worldwide in 2018, by type. For both sexes of all ages, the total number of cancer deaths was estimated to stand at approximately 9.56 million globally.
Of that figure, some 1.76 million were deaths due to lung cancer.
Hereditary Cancer occurs when more than one incident of cancer in a family is passed down from generation to generation due to inherited genetic mutations. An inherited germline mutation is present in the maternal egg “ova” or paternal sperms that form the embryos. Since all body cells are formed by multiplication of the forming fused egg and sperm, a germline mutation is typically resent in all body cells and so passes on through generations. On the other hand, an acquired (somatic) mutation does not come from a parent but rather happen due to environmental or lifestyle related risk actors. These mutations do not typically pass from generation to generation.