Introduction Less than half of the patients diagnosed with colorectal cancer (CRC) via emergency admissions have curative treatment intent, likely due to more advanced disease and poor performance status – highlighting the need for better surveillance. Right-sided CRC (RCC) is particularly associated with worse survival outcomes when compared to left-sided CRC (LCC).  NICE guidelines on CRC screening recommend that iron deficiency anaemia (IDA) in those aged 60 and above warrants urgent endoscopy. However, in those aged below 60, IDA requires positive testing for faecal occult blood prior to urgent endoscopy. 
Method This retrospective observational cohort study analysed haematological profiles (prior to histological diagnosis) of 265 patients with CRC. BSG guidelines were used to define anaemia [Hb <130 g/L (males) and <120 g/L (females)]. Further stratification was done based on severity [mild (>110 g/L), moderate (80–110 g/L) and severe (<80 g/L)].  We further sub-analysed patterns based on sex, age, tumour location (RCC vs. LCC) and severity of anaemia.
Results Of the 265 CRC patients, 116 (44%) were anaemic, of which 72 (27%) were normocytic, 43 (16%) were microcytic and 1 was macrocytic. Among 152 male patients, 67 (44%) were anaemic, of which 42 (27%) were normocytic and 24 (16%) were microcytic. Among 113 female patients, 49 (43%) were anaemic, of which 30 (27%) were normocytic and 19 (17%) were microcytic. Among 163 patients with LCC, 34 (21%) were normocytic and 13 (8%) were microcytic. Among 102 patients with RCC, 38 (37%) were normocytic and 30 (29%) were microcytic. Patients aged 60 and above had more cases of normocytic (31%) than microcytic (12%) anaemia. However, in comparison, patients aged below 60 had more cases of microcytic (30%) than normocytic (13%) anaemia. Leucocytosis and thrombocytosis were seen in only 14% and 12% of all CRC patients respectively.
Conclusion Prevalence of pre-diagnosis normocytic anaemia in CRC (especially in RCC and mild anaemia) highlights the importance of prompt evaluation of any type of anaemia in patients aged 60 years and above – without focusing on low MCV or ferritin levels. Microcytic anaemia should be considered sufficient to trigger urgent investigations for patients aged below 60.
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Disclosure of Interest None Declared
- colorectal cancer
- haematological profile
- microcytic anaemia
- normocytic anaemia