gms | German Medical Science

Objectives: We have recently shown, that the pattern and natural history of recurrence after bronchoplastic procedures cannot be sufficiently explained by stage and surgical radicality alone; therefore, the search for peculiar genetic characteristics of the primary tumor is justified. Integrin-linked kinase (ILK) is a protein kinase that links the cell-adhesion receptors, integrins and growth factors to the actin cytoskeleton and to a range of signaling pathways. ILK expression and activity are increased in a variety of human cancers, including NSCLC. However, little is known regarding the prognostic role of ILK in NSCLC operated by bronchoplastic procedures.

Methods: Samples of formalin fixed and paraffin-embedded pulmonary adenocarcinomas resected by bronchoplastic techniques were stained with a rabbit polyclonal antibody against ILK-1 (MBL, dilution 1:25) by a streptavidin-biotin method in an automated staining process (Ventana). Samples of reactive mesenchymal cell proliferation served as a control. The morphological pattern and intensity of staining were evaluated by two independent observers.

Results: Eighty percent of adenocarcinoma cases without recurrence were ILK-negative; 20% showed a faint granular staining of the cytoplasm of 70% of tumor cells. On the other hand, 70% of cases which developed recurrences in the long run showed a dense granular or diffuse cytoplasmic ILK staining in 70–100% of tumor cells. Normal lung parenchyma did not stain for ILK at all. In addition, 80% of all ILK-negative cases survived for more than five years.

Conclusions: In this study we show for the first time that the absence of ILK expression may be a favorable prognostic factor in pulmonary adenocarcinoma resected by bronchoplastic procedures. Therefore, ILK-negative primary NSCLC’s could be particularly suitable for surgical interventions with parenchyma-sparing resections. However, for further validation of the prognostic value of ILK in surgically treated NSCLC, these immunohistochemical results will be supplemented with molecular biological data.