p27^kip1 expression in non-small cell lung cancer is not an independent prognostic factor

Background: p27^Kip1 (p27) plays an important role in cancer cell cycle regulation. Recent evidence however, suggests that p27 may function as an oncogene rather than a tumour suppressor gene. Patients and Methods: Ninety-two patients with previously untreated non-small cell lung cancer (NSCLC) were studied for the association between the immunohistochemical localization of p27 through a semi-quantitative method and time-to-progression (TTP) and overall survival (OS). Results: The relationship between p27 H-Score and both TTP and OS was polynomial. Short TTP in patients with metastasis or whose tumors progressed during the eight-month period after diagnosis was statistically associated with overexpression of PIRH2 (p<0.001). In patients whose tumours progressed later, long TTP was associated with NSCLC of the non-adenocarcinoma type (p=0.027), p27 H-Score (p=0.032) and well-differentiated adenocarcinoma (p=0.047). None of the parameters correlated with duration of OS. Conclusions: This study showed that p27 H-Score may not appear to be an independent prognostic factor in patients with NSCLC.