GSTM1 and cancer: At multivariable analysis, referral without FIT (HR 1.42, 95% CI 1.06-1.91), and f-Hb ≥10 ug/g diagnosed outwith CRC prioritised pathways (HR 1.47, 95% CI 1.03-2.10) were associated with worse CSS independent of TNM stage.<h4>Conclusion</h4>Referral and investigation through cancer prioritised pathways guided by f-Hb concentration is safe in relation to CSS.