Integrin expression and survival in human breast cancer

Background. Integrin cell adhesion molecules are fundamental to numerous cellular functions including anchorage, differentiation and proliferation. Reduced expression of certain α and β integrin subunits in primary breast cancer cells has been correlated with increased invasion and metastasis. Conversely, over-expression of the α6 subunit has been linked to poorer survival. The objective of this study was to measure the survival of a cohort with breast carcinoma in relation to integrin expression and to evaluate their potential as prognostic indicators. Method. Integrin expression on samples from 99 consecutive patients with breast cancer was assayed using monoclonal antibodies to the subunits α1,2,3,6,V and β1,3,4,5. This cohort has now been followed prospectively for almost five years allowing for early assessment of survival in relation to integrin expression. Results. Whilst analysis of the data confirmed the relation of survival to proven predictors of tumour grade, tumour size and vascular invasion, statistical significance was not demonstrated with regard to both lymph node status and all integrin subunits studied. Conclusion. Previous research correlating certain integrin subunits with survival has not been confirmed in this study. Despite proven molecular importance in tumour cell adhesion, invasion and metastasis, integrin expression would appear not to translate clinically as independent indicators of prognosis, at least in the short-term.