Apoptotic tumor-cell death in response to cell proliferation is influenced by p53 status in resected non-small cell lung cancer.

To evaluate the influence of p53 status on postoperative survival and incidence of apoptosis (apoptotic index, AI) in non-small cell lung cancer (NSCLC), a total of 185 pathologic stage I patients were retrospectively analyzed. It was demonstrated by univariate and multivariate analyses that aberrant expression of p53 was a significant factor to predict a poor prognosis, which was caused by a significantly higher proliferative index (PI) in tumor with aberrant expression of p53 (52.7%) than that in tumor without aberrant expression of p53 (37.9%, P < 0.001). In addition, for tumor without aberrant expression of p53, mean AIs of the lowest-, the lower-, the higher-, and the highest-PI groups were 12.6, 12.9, 31.3, and 35.1, respectively, showing that incidence of apoptosis was markedly increased in response to cell proliferation (P = 0.002). In contrast, for tumor with aberrant expression of p53, no increase in incidence of apoptosis in response to cell proliferation was documented. These results clearly demonstrated that active cell proliferation and reduced apoptotic cell death in response to cell proliferation resulted in the poor postoperative prognosis in tumor with aberrant expression of p53.