Characteristic of Non-symptom Colorectal Cancer Detected by Immunochemical Fecal Occult Blood Test

摘要

[Introduction] A fecal occult blood (FOB) test is widely accepted as a useful tool in the screening of colorectal cancer. We assessed the usefulness of this test by comparing clinicopathological indices between patients with colorectal cancer detected by an FOB test and those detected by other methods. [Subjects and Methods] We investigated 689 patients with colorectal cancer treated in our department between 1992 and 2000. Of these, there were 122 patients with colorectal cancer diagnosed based on a positive occult blood test (FOB group). The remaining 567 patients were defined as non-FOB group, and the two groups were compared. [Results] FOB group had a smaller maximal diameter of tumors than that of non-FOB group. In addition, less advanced cancers were more frequently observed in FOB group with delete lower incidence of lymph node metastasis, liver metastasis, and peritoneal disseminated metastasis. Both the proportion of Dukes A colorectal cancer and the number of patients rated as cur A in curability, therefore, were greater in FOB patients. For treatment procedures, endoscopic resection was frequently done in FOB group, and they had favorable clinical outcomes as compared with non-FOB group. [Conclusion] Most colorectal cancers detected based on a positive FOB test were less advanced one, and patients with such cancers may benefit from receiving less invasive procedures. The clinical outcomes in FOB group were favorable. An FOB test is considered useful in detecting and diagnosing colorectal cancer.