Basal-cell carcinoma
Basal-cell cancer is a very common skin cancer. It is much more common in fair-skinned individuals with a family history of basal-cell cancer and increases in incidence closer to the equator or at higher altitude. There are approximately 800,000 new cases yearly in the United States alone. Up to 30% of Caucasians develop basal-cell carcinomas in their lifetime. In Canada, the most common skin cancer is basal-cell carcinoma (as much as one third of all cancer diagnoses), affecting 1 in 7 individuals over a lifetime.
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.