Abe Nobutsugu, Watanabe Takashi, Sugiyama Masanori, Yanagida Osamu, Masaki Tadahiko, Mori Toshiyuki, Atomi Yutaka
Department of Surgery, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka City, Tokyo 181-8611, Japan.
Am J Surg. 2004 Aug;188(2):181-4. doi: 10.1016/j.amjsurg.2003.12.060.
Although almost all (96%) the surgical cases of undifferentiated intramucosal early gastric cancer (EGC) have been found not to have lymph node metastasis (LNM), local treatment by endoscopic mucosal resection (EMR) is not accepted as an alternative treatment to surgery for this type of EGC. If a subgroup of patients with undifferentiated EGC with negligible risk of LNM can be defined, unnecessary surgery can be avoided. This study was conducted to determine this subgroup among undifferentiated EGC patients in whom the risk of LNM can be highly ruled out in an attempt to identify candidates who can be treated by EMR.
Data from 175 patients surgically resected for undifferentiated EGC were retrospectively collected, and clinicopathological factors were multivariately analyzed to identify predictive factors for LNM.
Multivariate logistic regression analysis identified two independent risk factors for LNM, namely, a large tumor (>/=20 mm, P = 0.011) and presence of lymphatic involvement (P = 0.0005). Using these two risk factors as the predictive factors, LNM was observed in 5.8% of patients who had neither of the two predictive factors, whereas 23.1% or 13.1% of patients with one or two predictive factors had LNM, respectively. In contrast, the LNM rate was calculated to be 60% in patients who had both factors. Lymph node metastasis was not found in any of 6 patients with small intramucosal lesions (<10 mm) without lymphatic involvement.
An intramucosal undifferentiated EGC that is smaller than 10 mm without lymphatic involvement can safely be treated by EMR alone, given the negligible possibility of LNM. When histological examination of endoscopically resected specimens shows lymphatic involvement or unexpectedly larger tumor size than that determined at pre-EMR endoscopic diagnosis, an additional surgical procedure should be considered.
尽管几乎所有（96%）未分化黏膜内早期胃癌（EGC）的手术病例均未发现有淋巴结转移（LNM），但内镜黏膜切除术（EMR）作为此类EGC的一种替代手术治疗方法尚未被广泛接受。如果能确定一组LNM风险可忽略不计的未分化EGC患者亚组，就可以避免不必要的手术。本研究旨在确定未分化EGC患者中LNM风险可高度排除的这一亚组，以识别可采用EMR治疗的候选患者。
回顾性收集175例因未分化EGC接受手术切除患者的数据，并对临床病理因素进行多因素分析，以确定LNM的预测因素。
多因素logistic回归分析确定了LNM的两个独立危险因素，即肿瘤较大（≥20 mm，P = 0.011）和存在淋巴管侵犯（P = 0.0005）。以这两个危险因素作为预测因素，在没有这两个预测因素的患者中，LNM发生率为5.8%，而有一个或两个预测因素的患者中LNM发生率分别为23.1%或13.1%。相比之下，同时具备这两个因素的患者LNM发生率经计算为60%。在6例黏膜内小病变（<10 mm）且无淋巴管侵犯的患者中均未发现淋巴结转移。
鉴于LNM可能性可忽略不计，对于直径小于10 mm且无淋巴管侵犯的黏膜内未分化EGC，单独采用EMR治疗是安全的。当内镜切除标本的组织学检查显示有淋巴管侵犯或肿瘤大小比EMR术前内镜诊断时确定的尺寸意外增大时，应考虑追加手术。
