Bcl-2 as a prognostic factor for survival in small-cell lung cancer.
BACKGROUND
The expression of Bcl-2 oncoprotein is associated with inhibition of apoptosis and prolonged cell survival. The purpose of this study was to investigate Bcl-2 protein expression in patients with small-cell lung cancer (SCLC) in order to see if it was related to clinicopathological features and to prognosis.


METHODS
Forty patients with SCLC were stained immunohistochemically using specific monoclonal antibody (DAKO-Bcl-2, 124). Bcl-2 positivity was determined as detection of the oncoprotein in greater than 10% of neoplastic cells.


RESULTS
Immunopositivity was present in 26 (60%) of SCLC patients. Twenty-three of 40 (57.5%) patients had limited disease at presentation, and 17 of 40 (42.5%) had extensive disease. There was not any correlation with Bcl-2 protein expression and clinicopathological parameters such as sex, age, smoking history and performance status. According to the extent of the disease, Bcl-2 expression was significantly higher in patients with extensive disease (p < 0.009). Bcl-2 expression was associated with significant shorter survival in patients with SCLC (Log Rank = -5.26; p = 0.00001). Cox regression analysis controlling for age, sex and tumor stage, confirmed that Bcl-2 expression (HR = 0.049 p < 0.0001) and N stage (HR = 0.152 p < 0.012) were an independent prognostic markers for poor prognosis. In CONCLUSION Bcl-2 oncoprotein was expressed in most cases of SCLC and its expression may have prognostic importance.
Ilievska Poposka
Biljana
B
Institute for Lung Diseases and Tuberculosis, Medical Faculty, Skopje, R. Macedonia. biljana.ilievska@yahoo.com
Smickova
S
S
Jovanovska Crvenkovska
S
S
Zafirovska Ivanovska
B
B
Stefanovski
T
T
Petrusevska
G
G
D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism / Q000401:mortality* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D055752:Small Cell Lung Carcinoma / Q000378:metabolism / Q000401:mortality* / Q000473:pathology; D016019:Survival Analysis; D015996:Survival Rate
D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2