Immunohistochemical study of an anti-apoptotic protein survivin in lung cancer

Objective. Survivin is a member of the inhibitor of apoptosis (IAP) family and is considered to play a significant role in the tumorigenesis and proliferation of various kinds of cancers. The purpose of this report is to clarify the relationship between the expression of survivin and prognosis in non-small cell lung cancer (NSCLC). Methods. We examined 100 NSCLC patients who underwent lobectomy in Tohoku University Hospital between October 2000 and December 2004. Expression of survivin and p53 was evaluated by immunohistochemistry. He- siijte The patients consisted of 71 men and 29 women. The average age was 66.1 years old. There were 71 cases of adenocarcinoma and 29 cases of squamous cell carcinoma. Immunohistochemical analyses showed that 64 cases had survivin expression in the cytoplasm, 40 cases had survivin expression in the nucleus, and 36 cases had expression in both the cytoplasm and nucleus. p53-positive staining was detected in 57 cases. There was no significant relationship between expression of survivin and p53. A multivariate analysis with Cox's proportional hazards model showed expression of survivin in the nucleus was an independent poor prognostic factor. Conclusion. Expression of survivin in the nucleus is suggested to be an independent poor prognostic factor in NSCLC. Survivin has several spliced variants and immunohistochemistry can't distinguish among these variants, so immunohistochemistry can't show which variants are important. Further examination with reverse transcription polymerase chain reaction (RT-PCR) is needed to elucidate survivin variants expression.