ABSTRACT
Objective To determine the concentration difference in protoporphyrin in cancerous intestine and to discuss its application in laser-induced autofluorescence diagnosis for colorectal cancer at early stage.Methods We detected the concentration of protoporphyrin Ⅸ in 30 patients with colorectal cancer and 30 control patients, as well as that in 60 cases of intestinal tissues (30 control tissues and 30 cancer tissues).Results The concentration of blood protoporphyrin Ⅸ in patients with colorectal cancer was significantly higher than that in the controls (P<0.05). Protoporphyrin Ⅸ concentration in the cancer tissue was significantly higher than that in the control tissues (P<0.05).Conclusion That the concentration of protoporphyrin in cancerous intestine becomes abnormally high may be the material basis for spectrum intensity peak of (644.3±5.7)nm in laser-induced autofluorescence diagnosis for colorectal cancer at early stage.