Is serum tryptase level a novel biomarker in colorectal cancer patients?

Abstract

e21134 Background: Tryptase is a serin protease stored in mast cell granules that plays a role in tumour angiogenesis. Mast cells (MCs) can release tryptase following c-Kit receptor activation. On the other hand colo-rectal cancer (CRC) is a well-established angiogenesis dependent tumour and anti-angiogenic based therapy is a standard treatment in metastatic CRC. This preliminary study aims to assess tryptase serum levels in 51 CRC patients before and after radical surgery. Methods: In this study patients with stage B and C CRC (according to Astler e Coller staging system) were selected. Samples of blood were taken from CRC patients between 7 and 9 a.m.1 day before and 1 day after curative surgery. Venous blood was dispensed into a tube for serum (Becton Dickinson Hemogard Vacutainer Systems, Plymouth, UK). Tryptase levels were measured using the UniCAP Tryptase Fluoroenzymeimmunoassay (Pharmacia,Uppsala, Sweden). Primary tumour tissue were also evaluated in terms of MCs positive to tryptase by immunohistochemistry utilizing an anti-tryptase primary antibody (clone AA1; Dako, Glostrup, Denmark). Results: Mean ± s.d. tryptase level pre-tumour surgical resection was 6.37 ± 4.57 μg/L, and mean ± s.d. tryptase level post tumour surgical resection was 5.15 ± 3.82 μg/L. A statistically significant difference between pre-tumour surgical resection and post-tumour surgical resection tryptase level concentrations was found: p=0.000 by t-test. A statistically significant correlation between MCs positive to trypase and serum tryptase levels pre-surgical resection was also found (r=086; p=0.000) by Pearson’s analysis. Conclusions: This pilot report analyzes the possible significance of serum tryptase levels changes in CRC patients who underwent curative surgery. Our results demonstrated higher serum tryptase levels CRC patients suggesting the release of tryptase from MCs of primary CRC tissue. As expected, after radical surgical resection, serum tryptase levels had decreased. We suggest that tryptase may play a role as a new predictive biomarker in CRC patients. In this context several tryptase inhibitors such as gabexate mesilate and nafamostat mesilate might be evaluated as adjuvant treatment in clinical trials.