Basal-cell carcinoma
In the United States approximately 3 out of 10 caucasians develop a basal-cell carcinoma during their lifetime. This tumor accounts for approximately 70% of non-melanoma skin cancers. In 80 percent of all cases, basal-cell carcinoma affects the skin of head and neck. Furthermore, there appears to be an increase in the incidence of basal-cell cancer of the trunk in recent years.
Head and neck squamous-cell carcinoma
Risk factors include tobacco consumption (chewing or smoking), alcohol consumption, Epstein-Barr virus (EBV) infection, human papilloma virus (HPV; esp. HPV 16 and 18) infection, betel nut chewing, wood dust exposures, consumption of certain salted fish and others (NCI Factsheet, 2013). EBV infection has been specifically associated with nasopharyngeal cancer. Reverse smoking was considered as a risk factor for oral cancer. "Cis-retinoic acid" (i.e. supplements of retinoic acid) intake may increase the risk of HNSCC in smokers. Low consumption of fruits and vegetables was associated with higher incidence of HNSCC.