THE PROGNOSTIC-SIGNIFICANCE OF ACCUMULATION OF P53 PROTEIN IN STAGE-III NON-SMALL-CELL LUNG-CANCER TREATED BY RADIOTHERAPY

In the present study the prognostic significance of accumulation of nu clear p53 protein on survival and freedom from local progression was i nvestigated. Formalin-fixed, paraffin-embedded sections obtained by br onchoscopy or mediastinoscopy were used to examine the expression of n uclear p53 protein using immunohistochemistry. In 37 cases (57%), over expression of the p53 protein was detected. No relation was found betw een p53 expression and other pretreatment variables. Response to radio therapy was found in 11 p53-negative cases (65%) versus 10 p53-positiv e cases (42%). Freedom from local progression was significantly better in the p53-negative cases as compared with the p53-positive cases. Th e p53-negative cases who responded to radiotherapy showed an excellent freedom from local progression rate after 2 years of 100%, whereas al l p53-positive cases without response to radiotherapy showed local pro gression within 24 months. Overall survival between p53-negative and - positive cases did not differ, however the disease-specific survival w as found to be worse in the p53-positive cases as compared to the nega tive cases (median survival 8.4 vs, 14.4 months (P < 0.05)). No correl ation was found between p53 expression and the frequency of distant me tastases. In conclusion, the results of this study suggest that p53 pr otein expression may be of prognostic value on freedom from local prog ression in non-small cell lung carcinoma.