TUMOR ASSOCIATED TRYPSIN INHIBITOR AS A PROGNOSTIC FACTOR IN RENAL CELL CARCINOMA:

Relationship between pancreatic secretory trypsin inhibitor and early recurrence of intrahepatic cholangiocarcinoma following surgical resection

OBJECTIVES

The extremely unfavorable prognosis of intrahepatic cholangiocarcinoma (ICC), even after surgical resection, is mainly attributed to a high rate of recurrence. The aim of this study was to identify the molecules associated with early recurrence of ICC following resection.

METHODS

Between December 1984 and July 2003, 46 patients with ICC underwent surgical resection. The clinical outcome of these patients was evaluated in view of the time of recurrence. Consequently, we categorized ICC patients into subgroups, based on the clinical results, and screened differentially expressed genes by DNA microarray analysis. Furthermore, the obtained results were validated in an independent sample set by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). Immunohistochemistry was performed to assess the expressed genes at the protein level.

RESULTS

The survival of patients with early recurrence, occurring within a year after surgical resection, was significantly poor after surgery and even after recurrence, as compared to that of patients whose recurrence occurred beyond a year after surgery. By the DNA microarray analysis, 13 differentially expressed genes were picked up, and quantitative RT-PCR reaction identified the pancreatic secretory trypsin inhibitor (PSTI) as a candidate gene associated with early recurrence of ICC after resection. This observation was confirmed through examination of an independent set of samples, in which the patients with higher levels of PSTI mRNA expression had significantly shorter recurrence-free survival. Immunohistochemically, PSTI was expressed in the cytoplasm of cancer cells.

CONCLUSIONS

PSTI might be a potential marker for identifying ICC patients with an increased risk of early recurrence after surgical resection.

High tissue expression of tumour-associated trypsin inhibitor (TATI) associates with a more favourable prognosis in gastric cancer

AIMS

The tumour-associated trypsin inhibitor (TATI) is a 6-kDa protease inhibitor with potential inhibitory effects on tissue degradation. In serum, increased levels have been associated with adverse prognosis in different forms of cancer. We assessed the tumour tissue expression and prognostic value of TATI in a surgically treated, single-institution series of patients with gastric cancer.

METHODS AND RESULTS

Using a monoclonal anti-TATI antibody, immunohistochemistry was performed on formalin-fixed paraffin-embedded tumour specimens from 336 patients. TATI expression was observed in 265 (79%) of the tumours. There was a significant association between high TATI expression and low stage (P = 0.007), superficial tumours (P = 0.005), and absence of nodal (P = 0.015) and of distant metastases (P = 0.022). In univariate analysis, patients with high TATI expression had a significantly more favourable 5-year cumulative survival compared with patients with negative to moderate immunostaining (43% and 28%, respectively, P = 0.006). On multivariate survival analysis stratified for estimated cure of surgery, stage (P < 0.0001) and age (P = 0.022) at the time of surgery were independent prognostic factors.

CONCLUSIONS

High TATI expression in tumour tissue was detected more frequently in patients with early-stage gastric cancer and seems to correlate with a favourable outcome.