Decreased serum levels of carboxylesterase-2 in patients with ovarian cancer.

Aims And Background: Carboxylesterase-2 has been identified as the key enzyme in the metabolic activation ofirinotecan, a topoisomerase I inhibitor commonly used in the treatment of many solid tumors. Previous studies have shown that carboxylesterase-2 is down-regulated in colorectal cancer following progression of the disease. However, very limited information is available on carboxylesterase-2 expression in ovarian cancer. The aim of the present study was to detect the serum level and the tissue expression of carboxylesterase-2 in human ovarian cancer patients at different stages of the disease.

Methods: Carboxylesterase-2 levels in the serum of ovarian cancer patients were investigated by western blot and ELISA and in the tumor mass of ovarian cancer patients by western blot.

Results: Both the serum carboxylesterase-2 level and the expression of carboxylesterase-2 in tumor tissues were significantly different among patients at different stages of the disease (n = 40). No positive correlation was found between the serum carboxylesterase-2 level and the cancer antigen 125 level (n = 40). Serum carboxylesterase-2 is more sensitive than cancer antigen 125 in detecting the early stage patient with ovarian cancer.

Conclusions: Our results indicate that serum carboxylesterase-2 level might be a potential marker in the diagnosis of the early stage ovarian cancer.