Non-anaemic iron deficiency should be investigated with the same priority as iron deficiency anaemia in fast track colorectal clinics-retrospective cohort study.

BACKGROUND: Since year 2000 the diagnostic criterion for fast track (FT) referrals for patients with suspected colorectal cancer (CRC) is used in the UK. Iron deficiency anaemia (IDA) is one of the diagnostic criteria. There is a strong evidence in the literature which suggests that Iron deficiency (ID) alone has a strong relationship with CRC. Non-anaemic Iron deficiency (NAID) and all other types of anaemia are investigated outside the scope of FT clinics. We postulated that patients with ID regardless of degree of anaemia have an increased risk of CRC. By confirming this hypothesis, we can broaden the scope of the diagnostic criterion for referral that can help to increase diagnostic yield of FT CRC services.

METHODS: A retrospective observational cohort study was conducted from a dedicated data for FT clinics from 2016-2018. Association between CRC and different forms of anaemia, Iron deficiency alone and bowel symptoms was determined.

RESULTS: Patients with iron deficiency (low MCV, MCH and ferritin) regardless of degree of anaemia were found more likely to have CRC. Factors like age, gender, family history and bowel symptoms (except abdominal mass) showed a very weak association with CRC in patients with ID.

CONCLUSIONS: ID without anaemia has a strong relationship with CRC and should be investigated with the same priority as IDA is investigated.