Clinical benefit of measuring both haemoglobin and transferrin concentrations in faeces: demonstration during a large-scale colorectal cancer screening trial in Japan.

Background: While the faecal immunochemical test for haemoglobin (FIT) is an important screening tool to detect gastrointestinal bleeding, false-negative cases resulting from the enterobacterial degradation of haemoglobin (Hb) have emerged. When faecal Hb tests have given false-negative results, it is considered that digestive bleeding diseases can be detected by measuring faecal transferrin (Tf), which is less susceptible to enterobacterial degradation. This study evaluated the benefit of measuring both Hb and Tf as markers of blood in the faeces during a large-scale colorectal cancer screening trial in Japan.

Methods: We screened 12,255 participants, i.e., 8223 men and 4032 women, for faecal Hb and Tf using a Discrete Clinical Chemistry Analyser NS-Plus C15 system.

Results: Among the 1232 participants with positive test results for blood, 417 were detected based solely on Tf, which increased the positive rate from 6.7% to 10.1%. The Hb and Tf concentrations were not correlated directly, thereby suggesting that Tf can detect a positive group that differs from that detected based on Hb. The positive rate for Tf alone was significantly higher in women (4.9%) compared with men (2.7%) (p<0.0001), which may be explained by the significantly higher constipation complaint rate in the Tf-positive group compared with the haemoglobin-only-positive group (p=0.0069).

Conclusions: The results of this large-scale colorectal cancer screening study suggest that analysing both Hb and Tf using an NS-Plus system should be beneficial for subjects who are missed by conventional Hb testing alone.