Predictive value of Ki-67, p53 protein, and DNA content in the diagnosis of gastric carcinoma

BACKGROUND. The ability to make a precise preoperative diagnosis is a valua ble and effective method in improving the prognosis of patients with gastri c carcinoma. The authors examined retrospectively whether preoperative hist opathologic analysis with p53 protein, Ki-67 labeling index, and DNA ploidy along with preoperative radiographic and endoscopic findings led to a prec ise preoperative diagnosis of patients with gastric carcinoma. METHODS. Histopathologic analysis of p53 protein, Ki-67 labeling index, and DNA content was performed on formalin fixed, paraffin embedded tissue. Tis sue sections from endoscopic and surgically resected specimens were stained immunohistochemically for p53 protein and Ki-67 labeling index, and the ce ll nuclear DNA content of the surgically resected primary lesion was measur ed using a microspectrophotometer. These analyses were performed on 16 pati ents with early gastric carcinoma (EGC) who were diagnosed with advanced ga stric carcinoma (AGC) based on the preoperative imaging findings and on 15 patients with AGC who were diagnosed preoperatively with EGG. RESULTS. Overexpression of p53 in the AGC group was significantly more freq uent compared with that in the EGC group (P = 0.0386). With regard to the c orrelation between lymph node metastases and p53 overexpression, there was no apparent relation in either the AGC group (P = 0.648) or the EGC group ( P = 0.726). The AGC group had significantly higher Ki-67 labeling indices c ompared with the EGC group (P = 0.0195). There was complete concordance bet ween endoscopic and surgically resected specimens with regard to the p53 an d Ki-67 labeling index findings. DNA ploidy in the primary tumor did not di ffer between the AGC and EGC groups. The survival rates for the EGC group w ere significantly superior to those for the AGC group (P = 0.0312). CONCLUSIONS, The findings of the current study suggest that in routine clin ical practice, the combination of preoperative imaging findings in addition to Ki-67 labeling indexes, and p53 protein analyses may be useful for the accurate diagnosis of EGG; however, DNA ploidy did not appear to reflect th e growth potential of gastric carcinoma. (C) 1999 American Cancer Society.