GSTM1 and cancer: The median time to diagnosis for those with a FIT < 10 μg Hb in our derivation cohort with 2 years follow up was 236 (IQR 64–728) days compared to 37 (IQR 25–67) days in those with a FIT over 10 μg Hb, and 533/599 (89%) cancers were diagnosed within a year of the FIT test.