Hanaoka N, Tanabe S, Mikami T, Okayasu I, Saigenji K
Department of Gastroenterology, Kitasato University School of Medicine, Sagamihara-City, Kanagawa, Japan.
Endoscopy. 2009 May;41(5):427-32. doi: 10.1055/s-0029-1214495. Epub 2009 May 5.
The clinicopathologic features of gastric cancers containing a mixture of differentiated-type and undifferentiated-type components remain uninvestigated. We evaluated the risk of lymph node metastasis and the feasibility of endoscopic submucosal dissection (ESD) for the treatment of mixed-histologic-type gastric cancers.
We histologically classified 376 cases of gastric cancer with submucosal invasion into four types (differentiated type, differentiated-type-predominant mixed type, undifferentiated-type-predominant mixed type, and undifferentiated type) and studied the clinicopathologic relations of each type to lymph node metastasis. Lymphatic invasion was evaluated by D2-40 immunostaining.
The overall prevalence of lymph node metastasis in gastric cancer with submucosal invasion was 16.5% (62/376). The prevalence of lymph node metastasis was 36.5% (23/63) in undifferentiated-type-predominant mixed type, which was significantly higher than those in the other three types (P < 0.001 vs. differentiated type, P = 0.013 vs. differentiated-type-predominant mixed type, and P = 0.003 vs. undifferentiated type). Lymphatic invasion, a depth of invasion of 500 microm or more from the lower margin of the muscularis mucosae (SM2), tumor size above 30 mm, and undifferentiated-type-predominant mixed histologic type were independent risk factors for lymph node metastasis. Submucosal cancers without these four risk factors were free of lymph node metastasis (0/41; 95 % confidence interval 0%-8.6%).
Undifferentiated-type-predominant mixed-type gastric cancer with submucosal invasion carries a high risk of lymph node metastasis. ESD can be indicated for gastric cancer with submucosal invasion provided that the following conditions indicating a low risk of metastasis are met: a depth of invasion of no more than 500 microm or more from the lower margin of the muscularis mucosae (SM1), no lymphatic invasion, a tumor size of no more than 30 mm, and a proportion of undifferentiated components below 50%.
含有分化型和未分化型成分混合的胃癌的临床病理特征尚未得到研究。我们评估了混合组织学类型胃癌的淋巴结转移风险以及内镜黏膜下剥离术（ESD）治疗的可行性。
我们将376例侵犯黏膜下层的胃癌组织学分类为四种类型（分化型、以分化型为主的混合型、以未分化型为主的混合型和未分化型），并研究了每种类型与淋巴结转移的临床病理关系。通过D2-40免疫染色评估淋巴管侵犯情况。
侵犯黏膜下层的胃癌中淋巴结转移的总体发生率为16.5%（62/376）。以未分化型为主的混合型中淋巴结转移发生率为36.5%（23/63），显著高于其他三种类型（与分化型相比，P<0.001；与以分化型为主的混合型相比，P=0.013；与未分化型相比，P=0.003）。淋巴管侵犯、从黏膜肌层下缘起侵犯深度达500微米或更深（SM2）、肿瘤大小超过30毫米以及以未分化型为主的混合组织学类型是淋巴结转移的独立危险因素。没有这四个危险因素的黏膜下癌无淋巴结转移（0/41；95%置信区间0%-8.6%）。
侵犯黏膜下层的以未分化型为主的混合型胃癌具有较高的淋巴结转移风险。对于侵犯黏膜下层的胃癌，如果满足以下表明转移风险低的条件，可考虑行ESD：从黏膜肌层下缘起侵犯深度不超过500微米（SM1）、无淋巴管侵犯、肿瘤大小不超过30毫米以及未分化成分比例低于50%。
