Combined analysis of p53 and retinoblastoma protein expressions in esophageal cancer

Background. p53 gene mutation and abnormal p53 protein expression, also los s of the retinoblastoma gene and protein expression are frequently associat ed with esophageal squamous cell carcinoma (ESCC). Recently, the prognostic significance of the combined analysis of p53 protein and retinoblastoma pr otein (pRB) has been reported in non-small cell lung cancer. However, in ES CC, the prognostic significance of the combined analysis of these proteins remains unclear. In this study, we immunohistochemically analyzed the p53 p rotein and pRB expressions in surgically resected ESCC, and we evaluated th e prognostic significance of the combination of these proteins. Methods. We analyzed p53 protein and pRB expressions immunohistochemically in 191 surgically resected ESCC cases. Overexpression of p53 and loss of pR B were considered abnormal. Results. Overexpression of p53 protein was detected in 79 patients (41%) an d decreased pRB nuclear staining occurred in 82 (43%). The Kaplan-Meier sur vival curve showed that absence of pRB expression was significantly associa ted with shortened survival (p = 0.001), whereas expression of p53 was not significantly associated with survival. Moreover, p53 and pRB status indivi dually were not independent prognostic factors in multivariate survival ana lysis. With respect to pRB and p53, the tumors could be grouped into four c ategories: p53-/ pRB+ (31%); p53-/pRB- (27%); p53+/pRB+ (26%); and p53+/pRB - (16%). Favorable prognosis was observed in patients with p53-/pRB+ tumors . Multivariate analysis showed p53-/pRB+ status to be an independent progno stic factor. Conclusions. The combination of p53 protein loss and pRB expression was ass ociated with good prognosis in patients with ESCC. (Ann Thorac Surg 2000;70 :913-7) (C) 2000 by The Society of Thoracic Surgeons.