The prevalence of iron deficiency among patients presenting with colorectal cancer

To examine prospectively the prevalence of iron deficiency among new patients presenting with colorectal cancer and to compare transferrin saturation and serum ferritin as markers of iron deficiency in this group of patients.

Data were gathered on all patients presenting with a new diagnosis of colorectal cancer over a 12-month period. Iron status was estimated and, when possible, confirmed by measurement of serum ferritin concentration and transferrin saturation. Iron status was further examined in relation to tumour site and Dukes' stage.

During the study 157 patients presented with a new colorectal cancer. Of these, 130 could be evaluated and 78[60%] had evidence of iron deficiency. Transferrin saturation was below the reference range in 55 patients, but serum ferritin was below in only 18 patients. Among the 49 patients with right-sided cancers, 39[80%] were iron deficient. Iron deficiency was significantly more likely in patients with right sided cancers compared with those with cancers at or distal to the splenic flexure (chi2 = 13, P < 0.001).

The majority of patients with a new diagnosis of colorectal cancer are iron deficient at presentation. In such patients transferrin saturation measurement is a more sensitive marker of iron deficiency than serum ferritin. The potential role of measuring serum transferrin saturation as an adjunct to faecal occult blood screening should be explored further.