LSVH with the CYP1A1 Msp1 rs4646903 risk (GG) genotype had a 2-fold increased risk of younger age at cancer diagnosis than those with the wild-type (AA) genotype (Adj HR: 2.03 [1.01–4.08], p = 0.034) (Supplementary Table S4). Here, CYP1A1 is linked to cancer.