Correlations between Integrin ανβ6 Expression and Clinico-Pathological Features in Stage B and Stage C Rectal Cancer

Integrin ανβ6 is highly expressed in a range of human cancers and frequently correlates with patient survival. This study examines correlations between ανβ6 expression and patient clinico-pathological features in Stage B and Stage C rectal cancer, including overall survival. Expression of ανβ6 was measured in 362 Stage B or C rectal cancer tissue samples at the tumour central region, invasive tumour front and adjacent non-neoplastic mucosa using immunohistochemistry. Distribution of ανβ6 was found to be significantly higher at the invasive front compared to central regions of the tumour (p<0.001) or adjacent non-neoplastic mucosa (p<0.001) suggesting ανβ6 plays a role in tumour cell invasion. However, integrin ανβ6 expression was not associated with clinico-pathological features or overall survival indicating it is not an independent prognostic marker differentiating Stage B or C rectal cancer. Previous ανβ6 studies have suggested the expression of ανβ6 is involved in the earlier stages (i.e. Stages A/B) of tumour progression rather than the later stages (i.e. Stages C/D). However, our study has revealed that in rectal cancer ανβ6 expression does not increase between Stages B and C, but may occur earlier, namely before or during Stage B cancer.