Analysis of Genotype and Allele Frequencies in CYP1A1 (T6235C), CYP1A1 (C4887A), CYP1A1 (A4889G) Gene Polymorphism with Tumor Stage, Tumor T Status, Lymph Node, Metastasis and Cell Differentiated Grade in Oral pre Cancer and Cancer. This evidence concerns the gene CYP1A1 and cancer.