Objective: Lung cancer is still the leading cause of cancer mortality. Antiapoptotic genes and protease inhibitors play an important role in the development of lung cancer.

Material and Method: p63, TTF-1 and maspin expression and their role in the differential diagnosis, overall survival, progression-free survival and other clinicopathological characteristics of the patients were investigated in 80 surgically-resected non-small cell lung carcinomas.

Results: The maximal tumor diameter range was 1.5–11 cm (mean: 4.06±1.8 cm). Forty-five (56.3%) tumors were adenocarcinoma, 23 (28.8%) squamous cell carcinoma, four (5%) large cell carcinoma, six (7.5%) large cell neuroendocrine carcinoma, one (1.2%) sarcomatoid carcinoma while one was (1.2%) both adenocarcinoma and squamous cell carcinoma. The patients with advanced TNM stage and a tumor diameter more than 3 cm had markedly poor survival. Immunohistochemically, p63 staining was present in 87.5% of squamous cell carcinomas, 4.3% of adenocarcinomas, 25% of large cell carcinomas, and 16.7% of large cell neuroendocrine carcinomas. Similarly, maspin was positive in 66.7% of squamous cell carcinomas and 17.4% of adenocarcinomas. The TTF–1 staining rate was higher in adenocarcinomas (84.8%). There was no immunoreactivity in squamous cell carcinomas (p<0.001). We found that p63 and TTF–1 had no significant effect on survival in either tumor group (p>0.05) while maspin has a negative prognostic effect in adenocarcinoma (p=0.048).

Conclusion: This study suggests that p63 and TTF–1 are reliable markers in non-small cell lung carcinoma and can be used in differential diagnosis. Maspin has been identified as a prognostic marker in adenocarcinoma. However, more studies are required to elucidate the significance of maspin.