Resection Of Early Gastric Cancer Research Articles

Helicobacter pylori prevalence and its spontaneous eradication rate after distal or proximal gastrectomy for gastric cancer: A multicenter prospective cohort study

AbstractBackgroundHelicobacter pylori (H. pylori) eradication is recommended in patients undergoing endoscopic resection for early gastric cancer to reduce recurrence. However, due to the possibility of spontaneous regression secondary to dynamic changes in the remnant stomach, the immediate eradication after gastrectomy for H. pylori carriers remains unclear. This study aimed to investigate the prevalence of H. pylori in Japanese patients with gastric cancer and the spontaneous eradication rate after distal or proximal gastrectomy.MethodsThis multicenter prospective cohort study was conducted at 22 institutions. Eligibility criteria was patients over 20 years planned to undergo R0 gastrectomy for gastric cancer. The primary endpoint was spontaneous eradication rate 1 year after distal or proximal gastrectomy. The prevalence of H. pylori infection before surgery and clinical features related to spontaneous eradication were examined.ResultsA total of 1247 patients were included in this study. The preoperative H. pylori status was positive in 756 patients and negative in 491. Seventy‐nine of the negative patients had an eradication history, totaling 835 (67%) patients preoperatively infected with H. pylori. The infection status of 541 patients was examined 1 year postoperatively; 285 were negative, with a 52.7% spontaneous eradication rate. Spontaneous eradication was significantly higher in male and older patients (>70 years); other factors, such as histological type, gastrectomy method and adjuvant chemotherapy presence, did not affect the rate.ConclusionsAs spontaneous H. pylori eradication occurred in more than half of the analyzed patients, retesting for H. pylori. should be considered before postoperative eradication therapy (UMIN000020280).

Tumor recurrence with disseminated liver metastases in a patient with resected early gastric cancer: a case of mixed adenoneuroendocrine carcinoma (MANEC).

Tumor recurrence with disseminated liver metastases in a patient with resected early gastric cancer: a case of mixed adenoneuroendocrine carcinoma (MANEC).

Optimal Surveillance of Metachronous Gastric Lesion after Endoscopic Resection of Early Gastric Cancer.

Endoscopic resection (ER)-a minimal invasive procedure, compared to surgical gastrectomy, with the advantage of preserving the entire stomach and maintaining the patient's quality of life-is a widely used curative treatment for early gastric cancers (EGCs). Despite its advantages, such as the preservation of the whole stomach, a large area of the gastric mucosa with histologic changes such as atrophy and intestinal metaplasia remains after ER, and so does the risk of metachronous gastric cancers (MGCs). Therefore, regular surveillance endoscopy after curative ER of EGCs is important so that MGCs are detected early and so minimally invasive ER remains a treatment option. To date, the optimal interval for surveillance endoscopy after curative ER of EGCs has not been established. Therefore, this review summarizes the results of the published studies on this topic with the aim of establishing the optimal surveillance interval for early identification of MGCs. Based on my review, the median timing of MGC occurrence is within 3 years, and reports suggest biannual endoscopy during the first 3 years; however, the evidence suggests that individual patient characteristics may influence the risk of MGCs. Therefore, stratified endoscopic strategies for surveillance based on patient characteristics, such as age, family history of gastric cancer, synchronous gastric lesions, and corpus intestinal metaplasia, should be applied.

Predictive biomarkers for metachronous gastric cancer development after endoscopic resection of early gastric cancer.

We aimed to identify predictive markers for metachronous gastric cancer (MGC) in early gastric cancer (EGC) patients curatively treated with endoscopic submucosal dissection (ESD). From EGC patients who underwent ESD, bulk RNA sequencing was performed on non-cancerous gastric mucosa samples at the time of initial EGC diagnosis. This included 23 patients who developed MGC, and 23 control patients without additional gastric neoplasms for over 3 years (1:1 matched by age, sex, and Helicobacter pylori infection state). Candidate differentially-expressed genes were identified, from which biomarkers were selected using real-time quantitative polymerase chain reaction and cell viability assays using gastric cell lines. An independent validation cohort of 55 MGC patients and 125 controls was used for marker validation. We also examined the severity of gastric intestinal metaplasia, a known premalignant condition, at initial diagnosis. From the discovery cohort, 86 candidate genes were identified of which KDF1 and CDK1 were selected as markers for MGC, which were confirmed in the validation cohort. CERB5 and AKT2 isoform were identified as markers related to intestinal metaplasia and were also highly expressed in MGC patients compared to controls (p<0.01). Combining these markers with clinical data (age, sex, H. pylori and severity of intestinal metaplasia) yielded an area under the curve (AUC) of 0.91 (95% CI, 0.85-0.97) for MGC prediction. Assessing biomarkers in non-cancerous gastric mucosa may be a useful method for predicting MGC in EGC patients and identifying patients with a higher risk of developing MGC, who can benefit from rigorous surveillance.

A machine learning model for predicting the lymph node metastasis of early gastric cancer not meeting the endoscopic curability criteria

BackgroundWe developed a machine learning (ML) model to predict the risk of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) who did not meet the existing Japanese endoscopic curability criteria and compared its performance with that of the most common clinical risk scoring system, the eCura system.MethodsWe used data from 4,042 consecutive patients with EGC from 21 institutions who underwent endoscopic submucosal dissection (ESD) and/or surgery between 2010 and 2021. All resected EGCs were histologically confirmed not to satisfy the current Japanese endoscopic curability criteria. Of all patients, 3,506 constituted the training cohort to develop the neural network-based ML model, and 536 constituted the validation cohort. The performance of our ML model, as measured by the area under the receiver operating characteristic curve (AUC), was compared with that of the eCura system in the validation cohort.ResultsLNM rates were 14% (503/3,506) and 7% (39/536) in the training and validation cohorts, respectively. The ML model identified patients with LNM with an AUC of 0.83 (95% confidence interval, 0.76–0.89) in the validation cohort, while the eCura system identified patients with LNM with an AUC of 0.77 (95% confidence interval, 0.70–0.85) (P = 0.006, DeLong’s test).ConclusionsOur ML model performed better than the eCura system for predicting LNM risk in patients with EGC who did not meet the existing Japanese endoscopic curability criteria.Mini-abstractWe developed a neural network-based machine learning model that predicts the risk of lymph node metastasis in patients with early gastric cancer who did not meet the endoscopic curability criteria.

Risk Assessment of Metachronous Gastric Neoplasm after Endoscopic Resection for Early Gastric Cancer According to Age at Helicobacter pylori Eradication.

Helicobacter pylori eradication can reduce the incidence of metachronous gastric neoplasm (MGN) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study evaluated the risk of developing MGN after ESD for EGC based on age at H. pylori eradication. Data of patients who underwent curative ESD for EGC with H. pylori infection between 2005 and 2018 were retrospectively analyzed. The patients were allocated to four groups according to age at H. pylori eradication: group 1 (<50 years), group 2 (50-59 years), group 3 (60-69 years), and group 4 (≥70 years). All patients were followed up for at least 5 years after ESD. The 5-year cumulative incidence of MGN was 2.1%, 7.0%, 8.7%, and 16.7% in groups 1, 2, 3, and 4, respectively (p<0.001), and groups 3 and 4 showed a significant increase in the risk of MGN (hazard ratio [HR], 4.66; 95% confidence interval [CI], 1.09 to 19.92 and HR, 10.75; 95% CI, 2.45 to 47.12). After adjustments for moderate to severe intestinal metaplasia based on the updated Sydney system, groups 3 and 4 remained significantly associated with MGN (HR, 4.40; 95% CI, 1.03 to 18.84 and HR, 10.14; 95% CI, 2.31 to 44.57). The incidence of MGN after ESD for EGC increased with age at H. pylori eradication. Age at H. pylori eradication ≥60 years was an independent risk factor for MGN, even after adjusting for the presence of advanced intestinal metaplasia.

Potential for expanding indications and curability criteria of endoscopic resection for early gastric cancer in elderly patients: results from a Japanese multicenter prospective cohort study

Evidence for endoscopic resection (ER) in elderly patients with early gastric cancer (EGC) is limited. We assessed its clinical outcomes and explored new indications and curability criteria. We analyzed data from a Japanese multicenter, prospective cohort study. Patients aged≥75 years with EGC treated with ER were included. We classified eCuraC-2 (corresponding to noncurative ER, defined in the Japanese gastric cancer treatment guidelines) into elderly-high (>10% estimated metastatic risk) and elderly-low (EL-L) (≤10% estimated metastatic risk). In total, 3371 patients with 3821 EGCs were included; endoscopic submucosal dissection was the prominent treatment choice. Among them, 3586 lesions met the guidelines' ER indications, and 235 did not. The proportions of en bloc and R0 resections and perforations were 98.9%, 94.4%, and 0.8%, respectively, in EGCs within the indications. In EGCs beyond the indications, they were 99.5%, 85.4%, and 5.9%, respectively, for lesions diagnosed as≤3 cm and 96.0%, 64.0%, and 18.0%, respectively, for those >3 cm. Curative ER and EL-L were observed in 83.6% and 6.2% of lesions within the indications, respectively, and in 44.2% and 16.8% of lesions<3 cm beyond the indications, respectively. The 5-year cumulative gastric cancer death rates after curative ER and elderly-high were 0.3% (95% confidence interval [CI], 0.2-0.6) and 3.5% (95% CI, 2.0-5.7), respectively. After EL-L, the rate was 0.9% (95% CI, 0.2-3.5) even without subsequent treatment. The usefulness of endoscopic submucosal dissection for elderly EGC patients was confirmed by their clinical outcomes. Lesions of≤3 cm and EL-L emerged as new ER indication and curability criteria, respectively. (Clinical trial registration number: UMIN000005871.).

Neutrophil-to-lymphocyte ratio to predict metachronous cancer after curative resection of early gastric cancer.

313 Background: We investigate the predictive value of inflammatory markers for occurrence of metachronous cancers among patients who underwent endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) and are judged as curative resection (CR). Methods: We enrolled patients who were diagnosed as EGC and underwent ESD during 2006 and 2020. We retrospective collected data of inflammatory indexes such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and erythrocyte sediment ratio (ESR). Results: A total of 1,011 patients underwent ESD for EGC, achieved CR and were followed up more than 12 months. Among them, 86 patients had metachronous cancers (85/1011, 8.4%) during 53.4 months of follow-up. Compared with patients without metachronous cancers, those with metachronous cancers were significantly older (66.9 vs. 63.8 years, P=0.004) and had higher NLR (2.1 vs. 1.8, P=0.002), however, other inflammatory indexes such as PLR and ESR were not significantly different between two groups. Kaplan-Meier analysis showed that patients with NLR ≥ 2.0 had significantly higher possibility of metachronous cancer compared with patients with NLR &lt; 2.0 ( P=0.049 by log rank test). After adjusting age, atrophy and Helicobacter pylori status, NLR was the only significant risk factor for metachronous cancer (odds ratio: 1.33, 95% confidence interval: 1.007-1.665, P=0.011). Conclusions: NLR may have a predictive value for occurrence of metachronous cancer after CR of EGC by ESD. Further thorough investigation is necessary to validate this outcome.

OGBN P37 Improving the Accuracy of Endoscopic Measurements of the Size of Gastrointestinal Lesions by a Guidewire Scale

Abstract Background Endoscopic measurement of lesion size is important for the assessment of the healing process, treatment strategies, and cancer staging. Consequently, accurate measurement of the size of the lesion is critical for proper candidate selection for endoscopic resection of early gastric cancer. A visual estimation of the size of the lesion has been widely used, but inaccuracy has been found. Hence, several endoscopic measurement methods have been proposed, but no reliable method has been used thus far. Therefore, we developed a guidewire scale for measuring the size of the lesion. This study focused on improving the accuracy on a practical level. Methods The guidewire scale consisted of green and yellow bands alternating on the wire, which were 5 mm for each band and a total of 30 mm in length. To assess the procedure’s validity and reliability, endoscopists estimated the size of the artificial lesions in the model by visually comparing them with the guidewire measurements. We found measurement error of the guidewire by 0.036±0.25 mm. The endoscopists determined the size of the lesion by the guidewire scale and used a numeral rating scale (NRS) to assess the satisfaction after the procedure. Results We enrolled 52 patients who were evaluated for the size of the lesion by the guidewire scale. The rate of completion of the procedure was 100% without any complications. Overall, the endoscopists’ satisfaction was good (NRS ≥ 8), but satisfaction was significantly higher in the dyspepsia group (P = 0.03). The mean of the size of the lesion was 10.7±8.9 mm, and small ulcer size (size ≤ 1 cm) displayed more satisfaction. The average time of measuring the lesion was 39.4±13.6 seconds, and the procedure time ≤ 30 seconds was highly satisfactory. Conclusions Our guidewire scale enhanced the accuracy of the endoscopic measurement of the size of the lesion. Thus, this guidewire scale could be used to estimate the sizes easily and safely in a clinical study.

Endoscopic resection of early gastric cancer

Endoscopic resection (ER) is an effective treatment for early gastric cancer (EGC) without metastases. Existing endoscopic mucosal resec-tion (EMR) is easy to perform, has few complications, and can be ap-plied when the lesion size is small. However, &lt;i&gt;en bloc&lt;/i&gt; and complete re-section rates vary depending on the size and severity of the lesion. EMR using the cap-mounted panendoscopic method and EMR after circum-ferential preamputation of the lesion are useful in the treatment of EGC. However, completely oversized lesions (≥2 cm) and lesions associated with ulcers or submucosal fibrosis are more likely to fail resection. En-doscopic submucosal dissection has been widely used to resect tu-mors larger than 2 cm in diameter and has a higher acceptable compli-cation rate and &lt;i&gt;en bloc&lt;/i&gt; and complete resection rates than EMR. ER for EGC is superior to surgical resection in terms of improving patient quali-ty of life. Additionally, compared to surgery, emergency rooms have a lower rate of treatment-related complications, shorter hospital stays, and lower costs. Accordingly, the indications for ER are expanding in the field of therapeutic endoscopy. Long-term outcomes regarding re-currence are excellent in both absolute and extended criteria for ER in EGC. Close surveillance should be performed after ER to detect early metachronous gastric cancer and precancerous lesions that can be treated with ER. Follow-up gastroscopy and abdominopelvic computed tomography scans every 6 to 12 months are recommended for patients who undergo curative ER for EGC on absolute or extended criteria.

Progress in the treatment of early gastric cancer with Laparoscopic and endoscopic cooperative surgery

With the introduction of minimally invasive methods into the field of surgery, the concept of early gastric cancer (EGC) treating has gradually changed from the pursuit of standardized traditional surgical methods to precise, individualized, interdisciplinary collaborative management. Both endoscopic therapy and laparoscopic surgery have their limitations for early gastric cancer treatment. Meanwhile, Laparoscopic and endoscopic cooperative surgery (LECS) combines the advantages of endoscopy and laparoscopy to perform local gastric resection and regional lymph node dissection, providing a more effective surgical approach for radical resection of early gastric cancer. The application of LECS in the treatment of early gastric cancer has been increasing, from the initial laparoscopy-assisted endoscopic full-thickness resection to the evolvement of a variety of improved procedures such as combined laparoscopic and endoscopic approach for neoplasia with a non-exposure technique, non-exposed endoscopic wall-inversion surgery, and the possibility of combined (sentinel lymph node drainage area) regional lymph node dissection or sentinel lymph node navigation surgery, which expands the indications for endoscopic surgery and maximizes the preservation of normal gastric tissue structure and function while ensuring radical treatment, and will certainly become an important development direction in the treatment of early gastric cancer in the future.

Integration of endoscopic screening, magnification, and resection for early gastric cancer: advantages of underwater EMR (with video)

Integration of endoscopic screening, magnification, and resection for early gastric cancer: advantages of underwater EMR (with video)

Endoscopic Resection of Early Gastric Cancer and Pre-Malignant Gastric Lesions.

Early gastric cancer comprises gastric malignancies that are confined to the mucosa or submucosa, irrespective of lymph node metastasis. Endoscopic resection is currently pivotal for the management of such early lesions, and it is the recommended treatment for tumors presenting a very low risk of lymph node metastasis. In general, these lesions consist of two groups of differentiated mucosal adenocarcinomas: non-ulcerated lesions (regardless of their size) and small ulcerated lesions. Endoscopic submucosal dissection is the technique of choice in most cases. This procedure has high rates of complete histological resection while maintaining gastric anatomy and its functions, resulting in fewer adverse events than surgery and having a lesser impact on patient-reported quality of life. Nonetheless, approximately 20% of resected lesions do not fulfill curative criteria and demand further treatment, highlighting the importance of patient selection. Additionally, the preservation of the stomach results in a moderate risk of metachronous lesions, which underlines the need for surveillance. We review the current evidence regarding the endoscopic treatment of early gastric cancer, including the short-and long-term results and management after resection.

Predictive factors of lymphatic metastasis and evaluation of the Japanese treatment guidelines for endoscopic resection of early gastric cancer in a high-volume center in Perú

PurposeThis study aimed to identify the predictive factors of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) and to evaluate the applicability of the Japanese treatment guidelines for endoscopic resection in the western population. MethodsFive hundred-one patients with pathological diagnoses of EGC were included. Univariate and multivariate analyses were conducted to identify the predictive factors of LNM. EGC patients were distributed according to the indications for endoscopic resection of the Eastern guidelines. The incidence of LNM was evaluated in each group. ResultsFrom 501 patients with EGC, 96 (19.2%) presented LNM. In 279 patients with tumors with submucosal infiltration (T1b), 83 (30%) patients had LNM. Among 219 patients who presented tumors > 3 cm, 63 (29%) patients had LNM. Thirty-one percent of patients with ulcerated tumors presented LMN (33 out of 105). In 76 patients and 24 patients with lymphovascular and perineural invasion, the percentage of LMN was 84% and 87%, respectively. In the multivariate analysis, a tumor diameter >3 cm, submucosal invasion, lymphovascular, and perineural invasion were independent predictors of LMN in EGC. No patient with differentiated, non-ulcerated mucosal tumors presented LNM regardless of tumor size. Three of 17 patients (18%) with differentiated, ulcerated mucosal tumors and ≤ 3 cm presented LNM. No LNM was evidenced in patients with undifferentiated mucosal tumors and ≤ 2 cm. ConclusionsThe presence of LNM in Western EGC patients was independently related to larger tumors (>3 cm), submucosal invasion, lymphovascular and perineural invasion. The Japanese absolute indications for EMR are safe in the Western population. Likewise, Western patients with differentiated, non-ulcerated mucosal tumors, and larger than 2 cm are susceptible to endoscopic resection. Patients with undifferentiated mucosal tumors smaller than 2 cm presented encouraging results and ESD could be recommended only for selected cases.

Endoscopic diagnosis and treatment in gastric cancer: Current evidence and new perspectives.

Gastric cancer is the fifth most common cause of cancer related deaths worldwide. Despite advancement in endoscopic techniques, the majority of the cases are diagnosed at late stage, when the curative treatment options are very limited. The early gastric cancer (EGC) on the other side is potentially curable, and in selected cases endoscopic resection techniques offer similar survival rates then surgical resection. The detection of EGC is endoscopically challenging and requires high quality examination. Recent data show that close to 10% of the gastric cancer cases had a previous negative endoscopy. This highlights the urgent need to improve the quality of the endoscopy services, what can be achieved by increasing the awareness of gastroenterologists and continuously monitoring the key performance indicators of upper gastrointestinal endoscopy. Newer endoscopic imaging techniques are also becoming commonly available to aid the detection of gastric premalignant lesions and EGC. High-definition endoscopy with image enhancement techniques is preferred over white light endoscopy to recognize these lesions, and they are also useful to determine the invasion depth of EGC. The endoscopic optical characterization of lesions is necessary for the selection of proper resection method and decide whether endoscopic resection techniques can be considered. Artificial intelligence systems aid the detection of EGC and can help to determine the depth of invasion. Endoscopic mucosal resection and endoscopic submucosal dissection requires centralized care and tertiary referral centers with appropriate expertise to ensure proper patient selection, high success rate and low adverse event rate. Appropriately scheduled endoscopic surveillance of high-risk patients, premalignant lesions and after resection of EGC is also important in the early detection and successful treatment of gastric cancer.

Metachronous gastric neoplasm beyond 5years after endoscopic resection for early gastric cancer.

The natural course of early gastric cancer (EGC) following endoscopic submucosal dissection (ESD) remains unclear. This study aimed to clarify the long-term clinical outcomes and risk factors of metachronous gastric neoplasm (MGN) 5years after ESD for EGC. We performed a retrospective analysis of patients who underwent ESD for EGC from July 2005 to October 2015 in Seoul National University Hospital. Long-term clinical outcomes and risk factors of MGN after 5years post-ESD were evaluated. Among the 2059 patients who underwent ESD for EGC, 1102 were followed up for > 5years. MGN developed in 132 patients 5years after ESD. During the median follow-up period of 85months, the cumulative incidences of MGN and metachronous gastric cancer were 11.7, 16.9, and 27.0 and 7.6, 10.8, and 18.7% after 5, 7, and 10years, respectively. In multivariable analysis, male sex (odds ratio 1.770; P = 0.042), severe intestinal metaplasia (odds ratio 1.255; P = 0.000), tumor-positive lateral margin (odds ratio 2.711; P = 0.008), < 5mm lateral safety margin (odds ratio 1.568; P = 0.050), and synchronous adenoma (odds ratio 2.612; P = 0.001) were positive predictive factors, and successful eradication of Helicobacter pylori (odds ratio 0.514; P = 0.024) was a negative predictive factor for MGN after 5years post-ESD. The cumulative MGN incidence was high even 5years post-ESD for EGC. Meticulous long-term endoscopic follow-up is mandatory, especially in male patients with underlying intestinal metaplasia, tumor-positive lateral margins, lateral safety margins of < 5mm, and synchronous adenomas.

Outcomes of endoscopic resection for early gastric cancer in very elderly patients: A nationwide population-based study.

403 Background: Few studies have investigated the long-term outcomes of endoscopic resection for early gastric cancer (EGC) in very elderly patients. The aim of this study was to determine the appropriate treatment strategy and identify the risk factors for mortality in these patients. Methods: Patients with EGC who underwent endoscopic resection from 2006 to 2017 were identified using National Health Insurance Data and divided into three age groups: very elderly (≥85 years), elderly (65–84 years), and non-elderly (≤64 years). Their long- and short-term outcomes were compared in the three age groups, and the survival in the groups was compared with that in the control group, matched by age and gender. We also evaluated the risk factors for long- and short-term outcomes. Results: A total of 8,426 patients were included in our study: 118 very elderly, 4,583 elderly, and 3,725 non-elderly. The overall survival (OS) and cancer-specific survival (CSS) rates were significantly lower in the very elderly group than in the elderly and the non-elderly groups. Congestive heart failure was negatively associated with CSS. A significantly decreased risk for mortality was observed in all groups (P-value &lt; 0.001). The very elderly group had significantly higher readmission and mortality rates within 3 months of endoscopic resection than the non-elderly and elderly groups. Further, cerebrovascular disease was associated with mortality within 3 months after endoscopic resection. Conclusions: Endoscopic resection for EGC can be helpful for very elderly patients, and it may play a role in achieving OS comparable to that of the control group.[Table: see text]

Local recurrence after curative resection of early gastric cancer by endoscopic submucosal dissection.

388 Background: We investigate the local recurrence rate and its risk factors among patients who underwent endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) and are judged as curative resection. Methods: We enrolled patients who were diagnosed as EGC and underwent ESD during 2006 and 2020. Local recurrence after ESD was confirmed by histopathologic evaluation by endoscopic biopsy at ESD site during endoscopic surveillance. Results: A total of 936 patients underwent ESD for EGC, achieved curative resection and were followed up more than 12 months. Among them, 14 cases of local recurrence were found (14/936, 1.5%) during 53.2 months of follow-up. Compared with patients without local recurrence, those with local recurrence showed male-predominance (677/922 vs. 14/14, P=0.025), frequent presence of synchronous tumor (123/922 vs. 6/14, P=0.001) and larger tumor size (16.3 vs. 26.3 mm, P=0.001). Kaplan-Meier graph also showed that local recurrence significantly occurred in subgroup with male, presence of synchronous tumor and tumor size ≥ 20 mm ( P=0.028, 0.009 and &lt;0.001 by log rank test, respectively). After propensity score matching for gender, age and comorbidities with 1:5 ratio, tumor size ≥ 20 mm was the only significant factor for local recurrence (odds ratio: 3.886, 95% confidence interval: 1.012-14.922, P=0.048) Conclusions: Endoscopists need to be cautious for local recurrence at ESD site even after curative resection of EGC, especially for large tumor size.

Two Cases of Metachronous Colorectal Metastasis after Curative Resection of Early Gastric Cancer

今回，我々は早期胃癌根治切除術後に異時性の大腸転移を来した2例を経験したので報告する．症例1は66歳の男性で，57歳時に開腹下幽門側胃切除術が施行され，病理検査所見はT1a（M），tub2>tub1，N1，Ly0，V0，pStage IBであった．術後8年5か月経過後に腹痛を主訴に受診した．腹部造影CTで横行結腸癌十二指腸浸潤もしくは十二指腸乳頭部癌の大腸浸潤と術前診断し根治手術を行った．術後の病理検査で胃癌の転移と診断された．症例2は77歳の男性で，75歳時に腹腔鏡下幽門側胃切除が施行され，病理検査所見はT1b2（SM2，1,700 μm），tub2>por，N1，Ly1，V0，pStage IBであった．術後2年1か月経過後に便潜血陽性にて受診した．大腸内視鏡検査で下行結腸にIspポリープを認め，病理検査で胃癌の転移と診断された．また，造影CTで骨転移も認め，化学療法を施行中である．

Clinicopathological features of endoscopically treated early gastric cancer with lymphovascular infiltration.

Lymphovascular infiltration (LVI) may play a critical role in radicality and prognostic assessment of early gastric cancer (EGC). However, risk factors for LVI in endoscopically resected EGC remain unknown. This study evaluated the clinicopathological characteristics and prognoses of patients who underwent endoscopic resection of EGC to identify potential risk factors of LVI. A cross-sectional study of patients who received gastric endoscopic submucosal dissection between February 1, 2012, and December 31, 2019, at two institutions was conducted. Among 1,462 lesions, 943 met the criteria for radical treatment considering features other than LVI and were included. The lesions were classified based on the presence of LVI. The clinicopathological characteristics of the two groups were compared. LVI was detected in 17 lesions (1.8%). The positivity rates of LVI were 0.7% (7/903) for intramucosal cancer and 25% (10/40) for submucosally invasive cancer. The LVI positivity rate was significantly higher for mixed-type cancer (lesions containing differentiated and undifferentiated-type carcinoma) than for non-mixed-type cancer (35.3 vs. 2.8%; P < 0.001) and for submucosally invasive cancer than for intramucosal cancer (58.8 vs. 3.2%; P < 0.001). In the multivariate logistic regression analysis, independent risk factors for LVI were mixed-type cancer (odds ratio; 95% confidence interval: 23.9; 5.0-115; P < 0.001) and submucosal invasion (58.7; 16.0-215; P < 0.001). Mixed-type cancer and submucosal invasion were risk factors for LVI in endoscopically resected EGC. These factors may play a critical role in the radicality and prognostic assessment of EGC.