Background Delays in referral for patients with colorectal cancer may occur if the presenting symptom is falsely attributed to a benign condition.

Aim To investigate whether delays in referral from primary care are associated with a later stage of cancer at diagnosis and worse prognosis.

Design and setting A national retrospective cohort study in England including adult patients with colorectal cancer identified from the cancer registry with linkage to Clinical Practice Research Datalink, who had been referred following presentation to their GP with a ‘red flag’ or ‘non-specific’ symptom.

Method The hazard ratios (HR) of death were calculated for delays in referral of between 2 weeks and 3 months, and >3 months, compared with referrals within 2 weeks.

Results A total of 4527 (63.5%) patients with colon cancer and 2603 (36.5%) patients with rectal cancer were included in the study. The percentage of patients presenting with red-flag symptoms who experienced a delay of >3 months before referral was 16.9% of those with colon cancer and 13.5% of those with rectal cancer, compared with 35.7% of patients with colon cancer and 42.9% of patients with rectal cancer who presented with non-specific symptoms. Patients referred after 3 months with red-flag symptoms demonstrated a significantly worse prognosis than patients who were referred within 2 weeks (colon cancer: HR 1.53; 95% confidence interval [CI] = 1.29 to 1.81; rectal cancer: HR 1.30; 95% CI = 1.06 to 1.60). This association was not seen for patients presenting with non-specific symptoms. Delays in referral were associated with a significantly higher proportion of late-stage cancers.

Conclusion The first presentation to the GP provides a referral opportunity to identify the underlying cancer, which, if missed, is associated with a later stage in diagnosis and worse survival.