Lymph node metastasis from intestinal-type early gastric cancer: experience in a single institution and reassessment of the extended criteria for endoscopic submucosal dissection.

BACKGROUND

Given the increasing use of endoscopic resection as a therapeutic modality for cases of early gastric cancer (EGC), it is very important to define strict criteria for the use of endoscopic mucosal resection and endoscopic submucosal dissection. To date, the criteria are almost entirely based on Japanese literature evaluating the risk of lymph node (LN) metastasis in patients with EGC.

OBJECTIVE

To analyze our own experience with the factors affecting LN metastasis and to reappraise the extended criteria for endoscopic submucosal dissection.

DESIGN

Retrospective, single-center study.

SETTING

University teaching hospital.

PATIENTS

This study involved 478 patients who underwent gastrectomy with LN dissection (n = 270, mucosal [m] EGC; n = 208, submucosal [sm] EGC).

INTERVENTION

Gastrectomy with LN dissection.

MAIN OUTCOME MEASUREMENTS

LN metastasis.

RESULTS

Overall, 12.6% (60/478) of patients with EGCs presented with LN metastasis (mEGC, 3.0% [8/270], smEGC, 25.0% [52/208]). Increased size, macroscopic type (elevated), depth of invasion, and lymphovascular invasion were associated with LN metastasis. In 270 cases of mEGC, there was no relationship between clinicopathologic features and LN metastasis. In the smEGC group, size, depth of invasion, and lymphovascular emboli were associated with an increased risk of LN metastasis. Significantly, LN metastasis was noted in EGCs falling within established extended endoscopic submucosal dissection criteria, that is, intestinal-type mucosal cancer of any size without ulcer and no lymphovascular emboli (2/146 [1.4%]) or < or =3 cm with no lymphovascular emboli and irrespective of the presence of ulceration (2/126 [1.6%]) or intestinal-type submucosal cancer (sm1, <500 microm) without lymphovascular invasion and measuring < or =3 cm in size (3/20 [15.0%]).

LIMITATIONS

Retrospective review of a single-center study.

CONCLUSION

We recommend that more centers survey their experiences of LN metastasis in cases of EGC to refine the criteria for endoscopic submucosal dissection as a therapeutic modality of intestinal-type EGC.