Prognostic significance of Notch3 immunoreactivity patterns in Caucasian colon adenocarcinoma patients

Introduction
Colon cancer is traditionally regarded as the most commonly diagnosed gastrointestinal malignant disease. Nevertheless, despite advances in diagnosis and novel therapeutic options, the clinical outcomes of patients are still not satisfactory.

Aim
To investigate the prognostic role of Notch3, an immunohistochemical study was performed on samples of colon adenocarcinoma tissues and adjacent non-pathological mucosa in Caucasian patients.

Material and methods
Paraffin-embedded colon adenocarcinoma samples were assessed immunohistochemically for Notch3 protein. Connections between Notch3 immunoexpression and clinicopathological factors including the 5-year overall survival (OS) were evaluated.

Results
The level of the Notch3 immunohistochemical reactivity was correlated with the grade of the histological differentiation (p < 0.001). A strong expression of Notch3 protein was detected more frequently in patients with G3 tumours than in patients with G1 tumours. Moreover, the significant difference was also detected between the patients with G1 tumour and those with G2. In the G2 patients a strong reactivity was described more frequently. The Kaplan-Meier survival analysis showed that the overall survival rate in the group of patients with a low expression level of Notch3 was significantly greater than that for patients with a moderate or strong level of Notch3 immunoreactivity (p < 0.001). A multivariate analysis demonstrated that the grade of tumour differentiation (p = 0.001) and Notch3 expression (p < 0.001) were independent risk factors for worse survival.

Conclusions
The high level of Notch3 immunoexpression was demonstrated to be associated with malignancy-related clinicopathological factors and 5-year overall survival of patients.