EGFR, TTF-1 and Mdm2 expression in stage III non-small cell lung cancer: a positive association.

New biological factors have not been extensively studied in stage III NSCLC as yet. The aim of this retrospective study was to assess the association between the expression and the prognostic role on survival of four biological markers in stage III NSCLC. Clinical characteristics were retrieved from the patients charts. EGF-R, Mdm2, p53 and TTF-1 expressions were evaluated by immunohistochemistry by three independent observers. Cox multivariate model was used to assess the impact of clinical and biological factors on patients' survival. A total of 84 stage III NSCLC patients, treated between 03/1987 and 08/2003, were included in the study. There was a statistically significant association between the expression of TTF-1 and EGFR (p=0.01) or TTF-1 and Mdm2 (p=0.04). Positive expressions for EGFR or TTF-1 were almost mutually exclusive. The status EGFR+/TTF-1--was mainly found in squamous cell carcinoma (18 among 19tumours). In multivariate analysis, only treatment with curative intent was independently associated with better survival (p=0.0004). In stage III NSCLC, there was a significant association between TTF-1 and EGFR or TTF-1 and Mdm2. The status EGFR+/TTF-1--was associated with squamous cell carcinoma.