Do Youn Park

Undifferentiated-type (UD-type) gastric cancer is associated with a high frequency of lymph node metastasis (LNM); however, recent reports indicate that LNM frequency varies according to specific histologic components. We conducted a multicenter study to define criteria for distinguishing low- and high-risk histology groups for LNM in UD-type gastric cancers. Histologic components were classified into four types: poorly cohesive signet ring cells (SRC), poorly cohesive non-signet ring cells (non-SRCs), poorly differentiated tubular (PD), and differentiated-type (D-type). Their proportions were measured semi-quantitatively. The proportion of extracellular mucin (EMC) and the predominant histologic components within EMC were also recorded. LNM risk was analyzed based on pathological findings. Overall, 2256 mucosal and 688 submucosal UD-type cancers were analyzed. A higher SRC amount was linked to lower LNM frequency. Non-SRCs showed no association with LNM. Increased PD and D-type were linked to more frequent LNM; however, PD-predominant cases (PD ≥ 90%) showed paradoxically lower LNM frequency. SRC proportion > 10% was essential for low LNM probability. PD or D-type proportion > 10% is important for high LNM probability. Most compositions with low LNM probability (< 5%) showed a SRC majority (SRC > 50%) and ≤ 10% of PD or D-type. Pure poorly cohesive carcinomas with > 10% SRC and no PD or D-type were classified as low-risk histology (LNM probability 2.6%-3.4%). We developed a risk assessment method for tumor histology based on the composition of all histologic components and defined criteria to identify low-risk histology for LNM among UD-type cancers.

The first edition of ‘A Standardized Pathology Report for Gastric Cancer’ was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Although the understanding of appendiceal mucinous neoplasms (AMNs) and their relationship with disseminated peritoneal mucinous disease have advanced, the diagnosis, classification, and treatment of AMNs are still confusing for pathologists and clinicians. The Gastrointestinal Pathology Study Group of the Korean Society of Pathologists (GPSG-KSP) proposed a multicenter study and held a workshop for the “Standardization of the Pathologic Diagnosis of the Appendiceal Mucinous Neoplasm” to overcome the controversy and potential conflicts. The present article is focused on the diagnostic criteria, terminologies, tumor grading, pathologic staging, biologic behavior, treatment, and prognosis of AMNs and disseminated peritoneal mucinous disease. In addition, GPSG-KSP proposes a checklist of standard data elements of appendiceal epithelial neoplasms to standardize pathologic diagnosis. We hope the present article will provide pathologists with updated knowledge on how to handle and diagnose AMNs and disseminated peritoneal mucinous disease.

Seung Yong Shin, Jie-Hyun Kim, Myeong-Cherl Kook, Do Youn Park, Keun Won Ryu, Il Ju Choi, Sung Hoon Noh, Hyunki Kim, and Yong Chan Lee. Gut and Liver 2021;15:44-52. https://doi.org/10.5009/gnl19328

Joo DC, et al. J Gastric Cancer. 2021 Dec;21:e39. https://doi.org/10.5230/jgc.2021.21.e39

Bong Eun Lee, Gwang Ha Kim, Nari Shin, Do Youn Park, and Geun Am Song. Gut and Liver -0001;0:. https://doi.org/10.5009/gnl20195

Background and Aims: Endoscopic resection (ER) for submucosal invasive colorectal cancer (T1 CRC) can be grouped as curative ER (C-ER) and non-curative ER (NC-ER). Little is known about the long-term outcomes of patients in these two groups. Therefore, we have evaluated the long-term outcomes in endoscopically resected T1 CRC patients in C-ER and NC-ER groups. Methods: We conducted a retrospective study on 220 patients with T1 CRC treated with ER from January 2007 to December 2017. First, we investigated the long-term outcomes (5-year overall survival [OS] and recurrence-free survival [RFS]) in the C-ER group (n = 49). In the NC-ER group (n = 171), we compared long-term outcomes between patients who underwent additional surgical resection (ASR) (n = 117) and those who did not (surveillance-only, n = 54). Results: T1 CRC patients in the C-ER and NC-ER groups had a median follow-up of 44 (interquartile range 32–69) months. There was no risk of tumor recurrence and cancer-related deaths in patients with C-ER. In the NC-ER group, the 5-year OS rates were 75.3% and 92.6% in the surveillance-only and ASR subgroups, respectively. The hazard ratio (HR) for ASR in NC-ER vs. surveillance-only in NC-ER was statistically insignificant. However, RFS rates were significantly different between the ASR (97.2%) and surveillance-only (84.0%) subgroups. Multivariate analysis indicated a submucosal invasion depth (SID) of >2500 µm and margin positivity to be associated with recurrence. Conclusions: The surveillance-only approach can be considered as an alternative surgical option for T1 CRCs in selected patients undergoing NC-ER.

Atrophic gastritis and intestinal metaplasia are well-known to be reliable indicators of gastric cancer risk. They are clinically important in deciding whether to recommend endoscopic surveillance. Herein I review the histopathologic diagnosis of atrophic gastritis and IM. Gastric atrophy is divided into metaplastic atrophy and non-metaplastic atrophy. IM is categorized as complete (type I) and incomplete (type II, III). Systematic interpretation of gastric atrophy and IM using the updated Sydney system or operative link on gastritis assessment is recommended. Furthermore, I suggest using the consensus definition of gastric atrophy and incomplete IM in the gastric biopsy pathology report to support the surveillance of high-risk gastric cancer group.