Anti-apoptotic proteins may be involved in tumor development, progression and the response to treatment. Bcl-2 is by far the most studied anti-apoptotic protein. A novel infibitor of apoptosis, designat ed survivin, and the heat shock proteins (HSPs) have recently been found in many human cancers. Immunohistochemical methods were used to determine the expression level of survivin, HSP 70 and bcl-2 in non-small cell lung cancer (NSCLC) to evaluate their clinical significance.

Tissue array slides were obtained from 99 surgically resected NSCLCs. Immunohistochemical staining was performed by an immuno-peroxidase technique using an avidin-biotinylated horseradish peroxidase complex. Anti-survivin rabbit polyclonal antibodies, anti-HSP70 mouse monoclonal antibodies and anti-bcl-2 mouse monoclonal antibodies were used as the primary antibodies.

Positive ataining of survivin was detected in 33.3% of the cases. Survivin positivity is associated with to females and recurrence. A nonstatistically significant trend toward increased survivin expression was observed in non-smokers, and its expression inversely correlated with the number of cigarettes smoked in smokers. HSP70 was detected in 84.8% but this did not correlate with the clinicopathologic characteristics. Bcl-2 was detected in 18.2% and its and its expression correlated to tumor recurrence. No significant difference in the median survival time was noted in a comparison of al cases with survivin expression and those without. There was no association betwwen HSP70 or bcl-2 expression and survival.

Survivin expression was significantly associated with females and tumor recurrence. In addition its expression was inversely associated with the number of cigarettes smoked. However, HSP70 and bcl-2 expression were not associated with the clinical parameters or survival. This suggests that measuring the survivin levels may be useful in identifying patients at high risk for disease recurrence. Therefore, survivin might be a new diagnostic/therapeutic target in cancer.