title: Thymidine phosphorylase activity in liver tissue and its correlation with multifocal occurrence of hepatocellular carcinomas.
abstract: BACKGROUND
  In hepatocellular carcinoma (HCC), new tumors develop in the residual liver within a few years after hepatectomy. However, the biological risk factors of multifocal occurrence of cancers remains unclear. In this study, the thymidine phosphorylase (TP) activity, which is known as an angiogenic factor, of cancerous and non-cancerous liver tissues in HCC was analyzed to determine its suitability as a biological marker of the multifocal occurrence of HCCs.
  
  
  METHODS
  Fresh tissues (tumor: HCC and adjacent liver tissue: N-HCC) from 63 patients with HCC and normal liver tissues (NL) from 6 patients without HCC were obtained. The TP activities of the tissues were analyzed by an enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  The mean TP activity of 63 HCCs (136 U/mg protein) was higher than that of 63 N-HCCs (81 U/mg protein) and that of 6 NLs (47 U/mg protein, p < 0.001). Multifocal occurrence of HCCs were detected in 17 patients. In these 17 patients, the mean TP activity of HCCs (145 U/mg protein) was not different from that of HCCs from the remaining 46 patients (133 U/mg protein, p = 0.272), however the mean TP activity of N-HCCs (110 U/mg protein) was significantly higher than that of N-HCCs from the remaining 46 patients (71 U/mg protein, p = 0.038). Moreover, only a high TP activity of N-HCCs was detected as a significant risk factor of multifocal occurrence of HCCs.
  
  
  CONCLUSIONS
  Patients who have tumors with high TP activity in the non-cancerous livers may have a risk of multifocal occurrence of HCCs in the residual liver.
authors.affiliation: First Department of Surgery, Faculty of Medicine, Tottori University, Nishi-cho 86-1, Yonago 683-8503, Japan. surgery1@grape.med.tottori-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Ikeguchi
authors.forename: T
authors.initials: T
authors.lastname: Sakatani
authors.forename: T
authors.initials: T
authors.lastname: Ueda
authors.forename: Y
authors.initials: Y
authors.lastname: Hirooka
authors.forename: N
authors.initials: N
authors.lastname: Kaibara
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis*; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000201:enzymology* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D003937:Diagnosis, Differential; D018572:Disease-Free Survival; D004797:Enzyme-Linked Immunosorbent Assay; D005500:Follow-Up Studies; D006391:Hemangioma / Q000201:enzymology; D006498:Hepatectomy; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008099:Liver / Q000201:enzymology / Q000293:injuries; D008103:Liver Cirrhosis / Q000201:enzymology; D008113:Liver Neoplasms / Q000098:blood supply / Q000201:enzymology* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D009363:Neoplasm Proteins / Q000032:analysis*; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000201:enzymology / Q000401:mortality; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000098:blood supply / Q000175:diagnosis / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D016609:Neoplasms, Second Primary / Q000098:blood supply / Q000175:diagnosis / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000201:enzymology; D011379:Prognosis; D016019:Survival Analysis; D013939:Thymidine Phosphorylase / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D013939:Thymidine Phosphorylase