Apoptosis and tumor regression in locally advanced non-small cell lung cancer with neoadjuvant therapy

Dysregulation of apoptosis is closely associated with malignant cell transformation. On the other hand, apoptosis is induced by chemotherapy or irradiation. Therefore, in 54 patients with locally advanced non-small cell lung cancer (NSCLC, 36 squamous cell carcinomas, 18 adenocarcinomas, stage IIIA/IIIB), apoptotic indices were comparatively analysed before onset and after termination of neoadjuvant therapy. The results were compared with the response to neoadjuvant therapy (extent of therapy-induced tumour regression) as well as the survival times. A statistically significant difference could not be established between pre-therapeutically and post-surgically established apoptotic indices (mean values: 0.93% vs. 1.1%). Neither before therapy nor after surgery did the apoptotic indices show a significant predictive value concerning different overall survival times. These results suggest that neoadjuvant therapy does not modify the extent of apoptosis in lung cancer in the long term. Only a few weeks after the completion of the neoadjuvant chemoradiotherapy this contributes to a net proliferation of the residual tumour tissue which is largely equivalent to that of the untreated tumour.