Integrin expression in breast cancer cytology: a novel predictor ofaxillary metastasis

The integrins are heterodimeric transmembrane receptors of varying α and β subunits that modulate cell adhesion toeach other and to the extracellular matrix. Loss of integrin expression on primary breast cancer frozen sections measured by immunohistochemistry may be related to the presence of axillary metastasis. The clinical application of this finding would be increased if integrin expression could also be shown to be reliably measured on breast cancer cells obtained by fine needle aspiration cytology. Axillary operations may be planned as a single stage procedure from outpatients, and neoadjuvant therapy protocols may be developed without surgery to the axilla. Expression of the αl, α2, α3, α6, αv, βl, β3 and β5 integrin subunits were measured by immunohistochemistry and immunocytochemistry in 58 patients. Integrin measurement by both these methods were found to be closely associated using the κ-test. Loss of expression of the α1, α2, α3, α6, αv, β1 and β5 integrin subunits measured by cytology and histology were each related to positive nodal status (χ2 test). Measuring integrin expression on cytology is of clinical value and may prove to have prognostic significance.