Cell proliferation and apoptosis in stage III inoperable non-small cell lung carcinoma treated by radiotherapy

J.A. Langendijk*, E. Thunnissen, J.W. Arends, J.M.A. de Jong, G.P.M. ten Velde, D. Guinee, J. Holden, E.F.M. Wouters

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Purpose: The purpose of this study was to assess the prognostic value of the expression of p53 and bcl-2, the apoptotic index and the expression of topoisomerase II alpha in patients with inoperable non-small cell lung cancer (NSCLC) treated with high dose radiotherapy. Patients and methods: A number of 161 patients with inoperable NSCLC treated with high dose radiotherapy (60 Gy) were included. Immunohistochemical analysis was used to assess the expression of nuclear p53-protein, topoisomerase II alpha and cytoplasmatic expression of bcl-2, while spontaneous apoptosis was assessed using in situ labeling. The minimal follow up period was 2 years. Results: Local control did not only depend on the presence of p53 expression, but also on the proportion of p53 positive cells. The most important prognostic factor was the apoptotic index. A high apoptotic index was associated with worse local control, more distant metastases and a significantly worse overall survival. No association was noted between the expression of bcl-2 and topoisomerase II alpha with any of the endpoints. Conclusion: This study indicates that p53 expression and the apoptotic index are prognostic factors with regard to local control in patients with inoperable NSCLC treated with radiotherapy and by combining these 2 factors, a clinically relevant estimation of the local control probability can be made. The apoptotic index turned out to be the only factor significantly related to survival.
Original languageEnglish
Pages (from-to)197-207
Number of pages11
JournalRadiotherapy and Oncology
Publication statusPublished - 1 Jan 2000

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