2012 Volume 50 Issue 3 Pages 345-350
The fecal occult blood test (FOBT) has been widely used as the main screening test for colorectal cancer (CRC). However, the efficacy of the FOBT is limited due to lower sensitivity for proximal CRC, as degradation of hemoglobin (Hb) in the colon is affected by the transit time of the stool. The hemoglobin-haptoglobin (Hb/Hp) complex is more stable than Hb alone in feces. Therefore, we performed a retrospective study, comprising 73 patients with CRC, 19 patients with colorectal adenoma, and 82 control subjects, to compare the performance of the Hb/Hp complex test with the FOBT. Hb/Hp complex and FOB were measured by BioNexia® Hb/Hp complex (DIMA, Goettingen, Germany) and Magstream® HemSP® (Eiken Chemical, Tokyo), respectively. The specificity of the Hb/Hp complex test was significantly lower than the FOBT (65.9% vs. 97.6%, P < 0.001), whereas the sensitivity was significantly higher (83.6% [Hb/Hp complex] vs. 60.3% [FOBT]; P < 0.001). In addition, the sensitivity of the Hb/Hp complex test tended to be higher than the FOBT for proximal cancer, but was not significantly different. These results indicate that a cutoff value may be required for the Hb/Hp complex test to optimize and improve the specificity of the test.
