胃癌和胃癌前病变中环氧合酶-2、p16的表达及其临床意义

背景：密切监测胃癌前病变是预防和及早发现胃癌的关键。目的：观察胃癌及其癌前病变中环氧合酶-2（COX-2）、p16的表达,探讨两者对胃癌早期诊断的意义。方法：以免疫组化染色检测20例正常胃黏膜、60例肠化生、60例上皮内瘤变和60例胃癌组织中COX-2和p16的表达,并分析两者的相关性。结果：正常胃黏膜、肠化生、上皮内瘤变和胃癌组织中的COX-2表达呈递增趋势,p16表达呈递减趋势。高级别上皮内瘤变和早期、进展期胃癌组织COX-2、p16表达阳性率与正常胃黏膜和肠化生组织相比差异有统计学意义（P〈0.05）,而前三者之间以及后两者之间无明显差异。COX-2、p16表达阳性率在小肠化生、完全型大肠化生与不完全型大肠化生之间以及早期与进展期胃癌之间无明显差异,但在高级别与低级别上皮内瘤变中差异有统计学意义（P〈0.05）。COX-2表达与p16表达呈负相关（P〈0.001）。早期胃癌组织中COX-2表达阳性同时p16表达阴性的比例显著高于高级别上皮内瘤变组织（P〈0.05）。结论：COX-2、p16或两者联合检测有助于监测和随访胃癌前病变、筛选胃癌高危人群,为胃癌的早期诊断提供了重要的检测方法。

Expressions and Clinical Significance of Cyclooxygenase-2 and p16 in Gastric Cancer and its Precancerous Lesions

Background： Monitoring gastric precancerous lesions is the key point for the prevention and early diagnosis of gastric cancer. Aims： To investigate the expressions of cyclooxygenase-2 （COX-2） and p16 in gastric cancer and its precancerous lesions, and to appraise the significance for the early diagnosis of gastric cancer. Methods： Expressions of COX-2 and p16 in tissues of 20 normal gastric mucosa, 60 intestinal metaplasia, 60 gastric intraepithelial neoplasia and 60 gastric cancer were determined by immunohistochemical staining, and the relationship between the two parameters was analyzed. Results： Expression of COX-2 was increased whereas expression of p16 was decreased stepwisely with the progression of gastric lesions, in the order of normal gastric mucosa, intestinal metaplasia, intraepithelial neoplasia and cancer. The positive expression rates of COX-2 and p16 in high-grade intraepithelial neoplasia, early and advanced gastric cancer were significantly different from those in normal gastric mueosa and intestinal metaplasia （P〈0.05）, whereas no significance difference was found between either the former three or the latter two. The positive expression rates of COX-2 and p16 were not statistically different between small intestinal metaplasia, complete and incomplete colonic metaplasia, between early and advanced gastric cancer, while statistically significant difference was found between low-grade and highgrade intraepithelial neoplasia （P〈0.05）. There was a negative correlation between the expression of COX-2 and that of p16 （P〈0.001）. The percentage of patients with positive expression of COX-2 accompanied by negative expression of p16 in early gastric cancer was significantly more than that in high-grade intraepithelial neoplasia （P〈0.05）. Conclusions： The detection of COX-2, p16 or the two combined is useful for the monitoring and follow-up of gastric precancerous lesions, as well as for the screening of high-risk population of gastric cancer, which may provide an important detection method for the early diagnosis of gastric cancer.