Endoscopy 2009; 41(5): 427-432
DOI: 10.1055/s-0029-1214495
Original article

© Georg Thieme Verlag KG Stuttgart · New York

Mixed-histologic-type submucosal invasive gastric cancer as a risk factor for lymph node metastasis: feasibility of endoscopic submucosal dissection

N.  Hanaoka1 , S.  Tanabe1 , T.  Mikami2 , I.  Okayasu2 , K.  Saigenji1
  • 1Department of Gastroenterology, Kitasato University School of Medicine, Sagamihara-City, Kanagawa, Japan
  • 2Department of Pathology, Kitasato University School of Medicine, Sagamihara-City, Kanagawa, Japan
Further Information

Publication History

submitted 21 August 2008

accepted after revision 27 January 2009

Publication Date:
05 May 2009 (online)

Preview

Background and study aims: 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.

Patient and methods: 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.

Results: 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 µm 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 %).

Conclusions: 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 µm 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 %.

References

N. HanaokaMD 

Department of Gastroenterology
Kitasato University School of Medicine

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Kanagawa 228-8520
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