Improving cancer survival in the UK is one of the leading items on the agenda of the government. Survival from gastrointestinal cancer is yet to come into line with Europe. In 2000 the department of health (DoH) introduced guidelines for referral of patients with suspected cancer. Iron deficiency anaemia (IDA) is one of the criteria for urgent referral for suspected cancer of the upper and lower gastrointestinal tract. The British Society of Gastroenterology (BSG) produced guidance on investigating patients with IDA to ensure identification of sources of occult blood from the GI tract. However due to a lack of clear guidance on how to streamline patients into upper or lower GI investigation pathways has resulted in significant delays. Furthermore there is evidence that there is significant delay in diagnosing proximal colon cancers in patients presenting with anaemia due to time spent in the investigation loop.
A literature review was conducted and this confirms that in patients above the age of 45 with unexplained IDA an upper GI cause is present in 40-60% of patients. Lower GI blood loss accounts for 26 to 31% of causes of anaemia. Colon cancer is the commonest cause with 11% on average for all causes of anaemia.
We also studied the incidence and profiles of anaemia in a cohort of patients with common GI malignancies. The incidence of anaemia that met the DOH and BSG guidance was 22% and 25% respectively.
We identified a potential for blood profiling to help differentiate upper and lower GI malignancies. Proximal colon cancer presented with a higher proportion of patients with anaemia and lower MCV, MCH, MCHC and a higher RDW as compared to upper GI cancers. We also identified a need to reduce the haemoglobin threshold for referral of any patient over the age of 45 with unexplained anaemia.
We conducted a prospective study assessing symptoms and blood profiles of patients referred with anaemia to a dedicated clinic. Using these profiles a scoring tool to predict likelihood of site of cause of anaemia was generated. We confirmed the poor sensitivities and specificities of symptoms for conditions of the GI tract in the presence of anaemia. However symptom combinations improved the sensitivity and specificity for identification of patients at risk of having serious conditions causing anaemia.
The scoring tool combined symptoms and blood profiles to aid in streamlining patients to the appropriate investigation. The tool generated a probability of having a serious condition causing anaemia in the upper or lower GI tracts. The scoring tool had a high discriminatory power with a sensitivity and specificity to GI causes of anaemia better than the current guidelines. A clinical pathway is proposed where the scoring tool is used to aid in streamlining investigation.