Cancer

Cancer is a class of diseases among humans and other species, characterized by uncontrolled division of cells and the ability of these cells to invade other tissues. This unregulated growth is caused by damage to DNA, resulting in mutations to genes that control cell division. If untreated, cancers may eventually cause death.


 * In Byzantium!, the elderly Christian leader Hebron is dying from cancer, the revelation of which humbles the Doctor, who up til then was immersed in self-pity over the loss of the TARDIS and separation from his companions.


 * In "The Eternity Contract," one of Lord Carnon's prisoners is a scientist with hopes of finding a cure for cancer, until Death takes him.


 * According to Divided Loyalties, Tegan's father died from cancer.


 * In Transit, the takeover of the Star Tunnel by an extradimensional intelligence is analogized to a viral cancer.


 * In the prelude to Deceit, a man living on Arcadia is dying from cancer as he writes his memoirs using burnt sticks for pencils and old sheets for parchment.


 * In Vampire Science, Carolyn McConnell has dreams of finding a cure for cancer when she starts out as a pre-med student in 1976 San Francisco. A portion of her passion is diverted towards an interest in vampires after the Eighth Doctor and Sam rescue her from one of these creatures.