Cell-cycle regulators and the Ki-67 labeling index can predict the response to chemoradiotherapy and the survival of patients with locally advanced squamous cell carcinoma of the esophagus

Background: We investigated whether aberrant p53 and p16 expression, the Ki-67 labeling index (LI), and int-2/cyclin D1 gene amplification predict the response to chemoradiotherapy (CRT) in patients with locally advanced esophageal squamous cell carcinoma (ESCC). Methods: p53 and p16 expression status, the Ki-67 LI, and int-2/cyclin D1 amplification were assessed by inummohistochemical staining and slot blot analysis in pretreatment endoscopic biopsy specimens of 41 patients with T4 or M1 Lym (distant lymph node metastasis) ESCC. All patients received a course of chemotherapy (5-fluorouracil and cisplatin) with radiotherapy. Results: The CRT therapeutic response rate was 71%, and resection after CRT was successful in 15 of the cases in which the CRT effect was significant. The cumulative survival rate after CRT in the p53-negative patients was significantly higher than in the p53-positive patients (P =.037). The mean Ki-67 LI in the CRT response cases was significantly higher than in the CRT no-response cases (P = .023). Multivariate regression analysis revealed high Ki-67 LI to be an independent variable linked to a pathologic complete response to CRT (P = .033). The cumulative survival rate after CRT in the group that was p53-negative and int-2/cyclin DI amplification-positive was significantly higher than in the other groups (P = .008). Conclusions: Evaluating predictive factors in pretreatment endoscopic biopsy specimens may allow selection of more suitable multimodal treatment for ESCC patients and improve their quality of life.