This is a<unk> . It should be noted that a cancer<unk> is a statistical event, which may or may not have a cause other than chance. There are other cancer<unk>  that occur without any obvious source of carcinogens.
List of cancer clusters
List of cancer types
List of cancer mortality rates
Sudden cardiac death classification
Disease Name differential diagnosis
Bedwetting epidemiology and demographics
Concussion diagnostic criteria
List of chemotherapy regimens