The CYP1A1 Msp1 rs4646903 risk (GG) genotype was significantly associated with an increased risk of younger age at any cancer diagnosis, while having any polymorphic allele for the CDC25C rs3734166 (genotypes GA and AA) was associated with an elevated risk of younger age at both CRC and any-cancer diagnosis in LS. This evidence concerns the gene CYP1A1 and cancer.