The predictive and prognostic value of the expression of p53 and bcl-2 in non-small cell lung carcinoma treated by radiotherapy

In the present study the predictive and prognostic value of nuclear p53 protein expression and cytoplasmatic bcl-2 expression was investigated in a group of 183 patients with inoperable non-small cell lune carcinoma, treated with high dose radiotherapy. These proteins are both involved in the regulation of apoptosis. The response rate decreased with an increasing number of p53-positive nuclei. Moreover the cumulative local progression rate (CLPR) was significantly higher in the group of patients with >90% p53-positive nuclei as compared to the group of patients with 90% or less p53-positive nuclei. No relation was found between the expression of bcl-2 and response, nor between bcl-2 and the CLPR. Both p53 and bcl-2 turned out to have no prognostic significance towards survival. We conclude that the expression of p53 has predictive value regaring response and prognostic significance in respect of local progression in inoperable NSCLC treated with radiotherapy. No such relations were found for the expression of bcl-2.