Social factors are intimately tied to issues such as race, economic status and religion. Generally, it is difficult to say that the behaviour of one group predisposes them to a particular cancer, but there are some renowned exceptions:
- tobacco consumption - smoking, chewing: polycyclic hydrocarbons in tobacco are potent carcinogens and have been linked to a number of cancers including those of the buccal cavity, nasopharynx, oesophagus, bladder and cervix
- dietary makeup:
- obesity is associated with an increased incidence of colorectal carcinoma, possibly due to the secretion of excess amounts of bile acid
- colonic carcinoma is more common in the developed world; it is suggested that the low-residue diet in this setting prolongs the time in which faecal carcinogens are in contact with the bowel wall
- over-salting of fish in South China may contribute to nasopharyngeal carcinoma