胃浆膜弹力纤维层在胃癌病理分期及预后判断中的意义

Significance of peritoneal elastic lamina in the pathological staging and prognosis of gastric cancer

目的探讨胃浆膜弹力纤维层(peritoneal elastic lamina,PEL)在胃癌p TNM分期及预后判断中的价值。方法回顾性分析2012年1月~2014年7月行全胃根治术且术后病理诊断为p T3期胃腺癌75例,选择肿瘤浸润深度最大且有浆膜存在的蜡块行改良EVG弹力纤维染色,观察PEL识别率及受侵情况;另选同时期p T4a期胃腺癌30例作为生存对照。结果 75例p T3期胃癌中PEL识别率为89.3%(67/75),其中43例(57.3%)肿瘤未突破PEL(p T3a),24例(32.0%)肿瘤突破PEL(p T3b);8例(10.7%)浆膜层未见PEL。p T3b期胃癌区域淋巴结转移个数多于p T3a期胃癌(P=0.02),淋巴脉管侵犯率高于p T3a期胃癌(P=0.04)。p T3b期患者总生存率低于p T3a期患者(P<0.05),与p T4a期患者总生存率相比,两者差异无统计学意义(P>0.05)。肿瘤是否突破PEL和淋巴脉管侵犯是影响p T3期胃癌患者生存的独立因素;N分期是影响胃癌患者生存的独立因素。结论 PEL在胃癌中识别率高,可以帮助判断胃癌肿瘤浸润深度,进而评估肿瘤与浆膜的位置关系;另外,突破PEL是影响p T3期胃癌患者预后的不良因素,可用于划分胃癌高危人群,突破PEL的p T3期胃癌可按p T4a期胃癌治疗。

Purpose To study the value of peritoneal elastic lamina （PEL） on pTNM staging and prognosis of gastric cancer. Methods A retrospective study was conducted on the 75 cases of pT3 gastric adenocarcinoma which were underwent total gastrectomy and diagnosed by pathologists from January 2012 to July 2014. One section containing the deepest tumor invasion covered with the peritoneum and the corresponding paraffin block were selected for modified EVG elastic staining. The recognition rate and invasive situation of the PEL was observed. 30 cases of pT4a gastric adenocarcinoma resected during the same period were examined for survival comparison. Results Among the 75 cases of pT3 gastric cancer, 43 cases （57.3%） did not break through the PEL （ pT3a ） , 24 cases （ 32. 0% ） broke through the PEL（ pT3b）, and the PEL was unidentified in 8 cases （ 10.7% ） . The number of regional lymph node metastases in pT3b gastric cancer was higher than that in pT3a gastric cancer （P = 0.02 ） , and the lymphovascular invasion rate was higher than that in pT3a gastric cancer （P =0.04）. The overall survival （OS） rate of pT3b patients was lower than that in pT3a patients （ P 〈 0.05 ） , and there was no significant difference with the OS rate of pT4a patients （P 〉 0. 05 ）. Whether the tumor breakthrough the PEL and the lymphovascular invasion were independent prognostic factor for OS in pT3 gastric cancer patients. N staging was an independent prognostic factor for OS in gastric cancer patients. Conclusion PEL has a high recognition rate in gastric cancer, it can help to determine the depth of gastric cancer invasion, and then assess the positional relationship between the tumor and the serosa. In addition, the invasion of PEL is an adverse prognostic factor for pT3 gastric cancer. It can be used to divide high-risk populations of gastric cancer, pT3 gastric cancer accompanied with PEL broken through could be treated as pT4a gastric cancer.