Increased expression levels of p53 correlate with good response to cisplatin-based chemotherapy in non-small cell lung cancer

In order to determine whether expression of the tumor suppressor gene p53 i n non-small cell lung cancer (NSCLC) correlates with chemotherapeutic respo nse, resected tumors from 18 patients with recurrent lung cancer who had un dergone complete resection and received chemotherapy after the initial tumo r recurrence were subjected to p53 immunostaining. Histological examination of the resected tumors revealed 11 adenocarcinomas, 6 squamous cell carcin omas and one adenosquamous cell carcinoma. Group 1 was less than or equal t o 50% (n=9) and group 2 >50% (n=9) p53-immunopositive. All patients receive d cisplatin-based chemotherapy after recurrence. No patient in group 1 achi eved response to chemotherapy whereas 2 and 3 in group 2 achieved complete and partial responses, respectively. The chemotherapy response rate of grou p 2 (56%) was significantly higher than that of group 1 (0%, p=0.009). The times to recurrence after tumor resection of group 2 was significantly bett er than that of group 1 (log-rank p=0.019, Wilcoxon p=0.042), and survival after chemotherapy of group 2 was also significantly better than that of gr oup I (log-rank p=0.023, Wilcoxon p=0.034). It is suggested that high p53 e xpression levels in tumors correlate with both good response to cisplatin-b ased chemotherapy and good survival of patients with advanced NSCLC.