Immunohistochemical status of the p53 protein and Ki-67 antigen using biopsied specimens can predict a sensitivity to neoadjuvant therapy in patients with esophageal cancer

Background/aims: The prediction of an effective adjuvant therapy is essential in order to increase the number of esophageal cancer cases demonstrating an excellent response. Correlation of the immunohistochemical expression of p53 protein and Ki-67 antigen were studied using biopsied specimens of advanced esophageal cancer. The combined staining status of both can help predict the efficacy of neoadjuvant therapy in patients with esophageal cancer. Methodology: The overexpression of p53 protein and the Ki-67 labeling percentage were immunohistochemically investigated in 95 biopsied specimens of advanced esophageal carcinoma resected between 1998 and 1996. All patients preoperatively received 1 course of either chemoradiotherapy or hyperthermo-chemoradiotherapy. Results: Thirty-nine specimens were positive for p53 protein staining (41.1%), and the treatment modalities were histopathologically effective in 71.8% of these 39 patients (28/39), while the efficiency rate was 58.9% (33/56) in patients with p53(-). On the other hand, the efficiency rate of patients with a high Ki-67 labeling percentage (≥ 30%) was 73.9%, which was significantly higher than that of those with a low Ki-67 labeling percentage (< 30%) (38.5%, P = 0.0013). The efficacy rate of the patients with both a high Ki-67 labeling percentage and p53(+) was 80%, while that of the patients with a low Ki-67 labeling percentage and p53 (-) was only 35.3% (P = 0.0098). The combination of a high Ki-67 labeling percentage and p53(-) particularly showed a high sensitivity to hyperthermo-chemoradiotherapy since the efficiency rate of these patients with hyperthermo-chemoradiotherapy was 81.5%, while the rate for those with chemoradiotherapy was 41.7% (P = 0.0129). Conclusions: An immunohistochemical analysis of p53 and the Ki-67 labeling percentage using biopsied specimens was thus found to effectively predict the efficacy of neoadjuvant therapies in patients with esophageal cancer.