Mismatch repair, minichromosome maintenance complex component 2, cyclin A, and transforming growth factor β receptor type II as prognostic factors for colorectal cancer: results of a 10-year prospective study using tissue microarray analysis.

Background: The expression of genes encoding a number of pathogenetic pathways involved in colorectal cancer could potentially act as prognostic markers. Large prospective studies are required to establish their relevance to disease prognosis.

Methods: We investigated the relevance of 19 markers in 790 patients enrolled in a large randomised trial of 5-fluorouracil using immunohistochemistry and chromogenic in situ hybridisation. The relationship between overall 10-year survival and marker status was assessed.

Results: Minichromosome maintenance complex component 2 (MCM2) and cyclin A were significantly associated with overall survival. Elevated MCM2 expression was associated with a better prognosis (HR = 0.63, 95%CI: 0.46 - 0.86). Cyclin A expression above the median predicted an improved patient prognosis (HR = 0.71, 95%CI: 0.53 - 0.95). For mismatch repair deficiency and transforming growth factor β receptor type II (TGFBRII) overexpression there was a borderline association with a poorer prognosis (HR = 0.69, 95%CI: 0.46 - 1.04 and HR = 2.11, 95%CI: 1.02 - 4.40, respectively). No apparent associations were found for other markers.

Conclusion: This study identified cell proliferation and cyclin A expression as prognostic indicators of patient outcome in colorectal cancer.