Quantification of Plasma β-Catenin mRNA in Colorectal Cancer and Adenoma Patients

Purpose: Colorectal cancer is an important cause of cancer deaths. Here, we focused our investigation on the β-catenin gene which is implicated in colorectal carcinogenesis and tested whether β-catenin mRNA is detectable in the plasma of colorectal carcinoma and adenoma patients using quantitative reverse transcriptase-PCR. Experimental Design: Plasma β-catenin mRNA was measured from 58 colorectal carcinoma patients, 49 colorectal adenoma patients, and 43 apparently normal subjects using intron-spanning primers and Taqman probes. Five clinicopathological parameters were studied and correlated with plasma β-catenin mRNA concentration. Additionally, 19 colorectal carcinoma patients after tumor removal were also recruited for plasma β-catenin mRNA measurement to further demonstrate the clinical usefulness of this test. Results: β-catenin mRNA was detected with median concentrations of 8737 (range: 1480-933,100), 1218 (range: 541-2,254) and 291 (range: 0-1,366) copies/mi plasma in colorectal carcinoma, colorectal adenoma, and apparently normal subjects, respectively. Statistical analysis demonstrated that plasma β-catenin mRNA concentration was correlated to tumor stage but not sex, age, lymph node status, and degree in differentiation. Moreover, plasma β-catenin mRNA concentration decreased significantly after tumor removal in 16 of 19 (84%) colorectal carcinoma patients. Conclusions: We conclude that plasma β-catenin mRNA may potentially serve as a marker for colorectal cancer.