Conclusions
FAK is expressed in more than 50% of stage I NSCLC lung cancer but not in normal lung alveoli and interstitial tissue. FAK expression is not associated with survival outcome in this North American cohort.
Methods
A retrospective tissue microarray (TMA) analysis of FAK protein expression by immunohistochemistry was performed in 157 surgically resected stage I NSCLC specimen and in the corresponding matched normal lung tissue. The FAK 4.47 monoclonal antibody was used for FAK immunostaining. The scoring system of triplicate tumor cores included intensity of staining plus extent of staining for a composite score that ranged from 0 to 6. The association between FAK score and survival was evaluated.
Results
There were 103 stage IA and 54 stage IB patients, with mean follow-up of 5.5 years. Normal lung alveoli and interstitial tissue had mean FAK score of 0 (median score 0, range 0 to 2). Tumor samples had mean FAK score 3.1 (median score 3.5, range 0-6), with 57% of the samples having FAK score ≥ 3. Continuous FAK score was not associated with demographic data, tumor histology, or grade, nor survival in this cohort of stage I NSCLC patients. Conclusions: FAK is expressed in more than 50% of stage I NSCLC lung cancer but not in normal lung alveoli and interstitial tissue. FAK expression is not associated with survival outcome in this North American cohort.