Prognostic significance of p27^KIP1 expression in resected non-small cell lung cancers: Analysis in combination with expressions of p16^INK4A, pRB, and p53

Background and Objectives: Whether a prognostic role for expression of the tumor suppressor gene (TSG) products exists in resected non-small call lung cancers (NSCLCs) remains controversial. Our study was performed to determine the value of TSGs expressions for patients survival in NSCLCs. Methods: We examined 108 resected NSCLCs for the expression of TSG products, p27^KIP1, p16^INK4A, pRB, and p53 that govern cell cycle transition by immunohistochemistry and compared them with patient clinical characteristics and prognoses. Results: Abnormal expressions of p27^KIP1, p16^INK4A, pRB, and p53 were found in 61 (57%), 53 (49%), 42 (39%), and 48 (44%), respectively, of the 108 NSCLCs. Univariate analysis showed abnormal expression of p27^KIP1 to be a strong indicator for poor patient survival, not only in the total cohort (P = 0.0024), but also in subgroups with T1-T2 (P = 0.016), NO (P = 0.047), and squamous cell carcinomas (P = 0.026), but not according to the expression of p16^INK4A, pRB, or p53. In the Cox regression analysis, p27^KIP1 expression was found to be an independent prognostic factor (P = 0.0148) and associated with pathological stage (P= 0.0278). Conclusions: Our results suggest that abnormal p27^KIP1 expression may be a useful indicator to predict postoperative prognosis, especially in patients with early stage NSCLCs, as compared to other TSG products examined.