High-grade Papillary Early Gastric Carcinoma With High Risk for Lymph Node Metastasis and Poor Prognosis: A Clinicopathologic Study of 96 Cases Among 1136 Consecutive Radical Gastrectomies.

Papillary early gastric carcinoma (EGC) is believed to have a low risk of lymph node metastasis (LNM) and thus can be resected endoscopically. We observed anecdotally that some papillary EGC tumors showed conspicuous high-grade dysplastic features, but the significance of these observations is unknown. In this bicenter study we investigated papillary EGCs that were divided into high-grade (n=96) and low-grade (n=118) groups among 1136 consecutive EGC radical resection cases. Concurrent 464 well-moderately differentiated tubular EGCs were served as the control group. Compared with low-grade papillary and well-moderately differentiated tubular EGCs, high-grade papillary EGC displayed significantly larger sizes (mean 2.51 cm), higher frequencies of the elevated macroscopic type (51%), lymphovascular invasion (LVI) (38.5%), and LNM (31.2%). Low-grade papillary EGCs exhibited a higher prevalence of the elevated macroscopic type, but not LVI nor LNM, compared with tubular EGC. Independent risk factors for LNM included high-grade histology, female sex, distal location, submucosal invasion, and LVI. The 5-year overall survival rate was significantly lower in high-grade (79.6%) papillary than in low-grade (88.9%) papillary or tubular (92.8%) EGCs, while no significant difference in prognosis was observed in the latter 2 groups. Age of 66 years or older and LNM were independent risk factors for overall survival. In conclusions, high-grade papillary EGC was associated with high frequencies of LVI, LNM, and poor prognosis, and thus unsuitable for endoscopic therapy, while low-grade papillary EGC showed clinicopathologic features and prognosis similar to well-moderately differentiated tubular EGC and may be treated endoscopically in appropriate clinical settings.