How much does family history, heredity, and ethnicity play into developing oral cancer, or is it primarily caused by tobacco, alcohol etc..

Mostly smoking : Though family history and genes always can play a role in susceptibility to cancer, the biggest factor is tobacco in any form, and alcohol contributes.

Smoking/chewing: Genetics can and does play a role in the incidence of oral cancers and all other cancer. However, there is no question that smoking and especially chewing tobacco long term puts you at a much higher overall risk of getting oral cancer. This risk is compounded with high usage of alcohol as well.

None : Major culprit of oral cancer is nicotine and alcohol . Ethnicity, family history znd heredity have not been implicated in common forms of oral cancer.