Comparative Expression of Apoptotic Markers in Lung Adenocarcinoma and Squamous Cell Carcinoma

Lung cancer is still an oncology challenge. A 5-year survival reaches less than 20 % of patients. Apoptosis disturbances are a key step in cancer development. The evaluation of apoptosis markers has a great potential in lung cancer. The goal of our study was a comparative evaluation of apoptosis regulators: p53, Bcl-2, Bax, COX-2, and survivin in lung adenocarcinoma (AC) and squamous cell carcinoma (SCC). We also evaluated the relationship between apoptosis markers and clinicopathological parameters. Fifty six patients with non-small cell lung cancer (NSCLC) were included into the study (20 women and 36 men). AC was diagnosed in 30 and SCC in 26 cases. The evaluation of markers was performed using an immunohistochemical method on paraffin embedded tissue specimens. We used monoclonal antibodies for p53, bcl-2, and COX2-proteins (clone DO7, bcl-2/100/D5, and 4H12, respectively), Bax (B-9 clone) and survivin (clone 12C4). The results of immunostaining were viewed by light microscopy. We revealed significantly more frequent expression of Bax and survivin in lung AC than SCC (p < 0.01 and p < 0.019). Bcl-2 immunoreactivity was seen more often in AC without lymph node metastases than with metastases (p = 0.046). There was no correlation between the apoptosis markers and gender or the presence of vessel emboli. A greater variability in markers expression was seen in lung AC than SCC. There were significant differences in the Bax and survivin expression in the two major pathological types of NSCLC. We did not revealed any correlation between the markers and TNM characteristics, accept for Bcl-2 presence along with the lymph node involvement in the AC group.