Treatment and prognosis of early multiple gastric cancer

Chinese national clinical practice guidelines on the prevention, diagnosis, and treatment of early gastric cancer

BACKGROUND

Gastric cancer is one of the most common malignant tumors in the digestive system in China. Few comprehensive practice guidelines for early gastric cancer in China are currently available. Therefore, we created the Chinese national clinical practice guideline for the prevention, diagnosis, and treatment of early gastric cancer.

METHODS

This clinical practice guideline (CPG) was developed in accordance with the World Health Organization's recommended process and with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) in assessing evidence quality. We used the Evidence to Decision framework to formulate clinical recommendations to minimize bias and increase transparency in the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and the Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guidelines to ensure completeness and transparency of the CPG.

RESULTS

This CPG contains 40 recommendations regarding the prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer based on available clinical studies and guidelines. We provide recommendations for the timing of Helicobacter pylori eradication, screening populations for early gastric cancer, indications for endoscopic resection and surgical gastrectomy, follow-up interval after treatment, and other recommendations.

CONCLUSIONS

This CPG can lead to optimum care for patients and populations by providing up-to-date medical information. We intend this CPG for widespread adoption to increase the standard of prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer; thereby, contributing to improving national health care and patient quality of life.

Case Report: A rare synchronous multiple gastric carcinoma achieved progression-free disease through NGS-guided serial treatment

Synchronous multiple gastric carcinoma (SMGC) is a rare condition characterized by the simultaneous occurrence of two or more primary malignant tumors in the stomach, each with its own distinct pathological morphology. SMGC differs from gastric metastases, which originate from primary gastric or non-gastric tumors. At present, the incidence of SMGC is low in China, with no established guidelines for standard treatment. Here, we report a rare case of advanced SMGC that achieved long-lasting clinical benefits through a treatment strategy informed by next-generation sequencing (NGS). Dynamically monitoring of the tumor and/or circulating cell-free DNA guided the patient's treatment sequentially. The patient received anti-HER2 therapy, followed by immunotherapy, pembrolizumab in combination with trastuzumab and chemotherapy, and ultimately underwent successful total gastrectomy. This case highlights a novel approach of utilizing liquid biopsy-based NGS to gain insights into disease progression and molecular response to NGS-guided treatment in SMGC patients.

Clinicopathological features and risk factors analysis of lymph node metastasis and long-term prognosis in patients with synchronous multiple gastric cancer

Background

As a common malignancy, gastric cancer (GC) remains an important threat to human’s health. The incidence of synchronous multiple gastric cancer (SMGC) has increased obviously with technical advances of endoscopic and pathological examinations. Several studies have investigated the relationship between SMGC and solitary gastric cancer (SGC). However, little is known about the relationship between early and advanced SMGCs, and the independent risk factors of lymph node metastasis and prognosis in SMGC patients remain unclear.

Methods

We retrospectively collected 57 patients diagnosed as SMGC and underwent radical gastrectomies from December 2011 to September 2019. Epidemiological data and clinicopathological characteristics of all patients were recorded. Postoperative follow-up was performed by telephone or outpatient service. Chi-squared test or Fisher’s exact test was adopted in analysis of categorical data. Continuous data were analyzed by using unpaired t test. Univariate and multivariate analyses were performed to investigate the independent risk factors of lymph node metastasis and tumor recurrence of SMGC.

Results

There were 45 males and 12 females. The average age was 62.1 years old. There were 20 patients with early SMGC and 37 patients with advanced SMGC. Most of patients (91.2%) had two malignant lesions. Tumor recurrence occurred in 8 patients, among which 7 patients died from recurrence. The rates of total gastrectomy, tumor size ≥ 2 cm, poorly differentiated type, lymph node metastasis, ulcer and nerve invasion, and preoperative CEA level were significantly higher in advanced SMGC patients compared to those with early SMGC. Lymphovascular cancer plug and preoperative CA125 were the independent risk factors of lymph node metastasis in patients with SMGC. Lymph node metastasis, nerve invasion, and preoperative AFP might be the risk factors of tumor recurrence of SMGC, but need further validation.

Conclusions

In patients with SMGC, the presence of tumor size ≥ 2 cm, poorly differentiated type, lymph node metastasis, ulcer, nerve invasion, and relatively high preoperative CEA level might indicate the advanced SMGC. More attention should be paid to lymph node metastasis in SMGC patients with lymphovascular cancer plug and high preoperative CA125. Lymph node metastasis, nerve invasion, and preoperative AFP might be associated with recurrence of SMGC, needing further validation.

Clinicopathological features, risk of lymph node metastasis and survival outcome of synchronous multiple early gastric cancer

OBJECTIVE

To determine clinicopathological features, risk of lymph node metastasis (LNM) and survival outcome in synchronous multiple early gastric cancer (MEGC) patients.

METHODS

A total of 338 solitary early gastric cancer (SEGC) and 26 MEGC patients who underwent surgical resection were retrospectively reviewed. The clinicopathological features and predictive factors for MEGC patients were evaluated. Also, we analyzed risk factors for LNM and compared survival difference between SEGC and MEGC patients.

RESULTS

The frequency of multiple synchronous lesions was 7.1% in early gastric cancer (EGC) patients. The main and minor lesions were mostly confined to the same third of the stomach (84.6%, 22/26), and the most common location was the lower third of the stomach. With regard to the number of coexisting lesions, most of the patients had two lesions and more than three lesions were not common. Tumor size≤2cm (OR:2.684, 95%CI:1.131-6.368, P<0.05) and the presence of atrophic gastritis (OR:2.418, 95%CI:1.052-5.555, P<0.05) were independent risk factors for synchronous MEGC. There was no significant statistical difference between SEGC and MEGC for LNM (17.5% vs 23.1%, P=0.311). The number of coexisting lesions was not associated with the risk of LNM in EGC. In addition, the survival outcome of MEGC patients was similar to that of SEGC (5-year RFS rate, 96.0% vs 93.7%, P=0.329;5-year OS rate, 96.0% vs 88.3%, P=0.479).

CONCLUSION

Meticulous endoscopic examination at the initial diagnosis of MEGC was very important, especially for those with precancerous lesions such as atrophic gastritis. In terms of treatment methods, endoscopic resection may be equally suitable for synchronous MEGC if the lesions fulfilled its indication criteria.

Molecular characteristics of synchronous multiple gastric cancer

Rationale: Multiple gastric cancer (MGC) is characterized by the presence of more than two different tumors in the stomach. However, the clonal relationship and carcinogenesis of MGC remain unclear. We investigated the clonal relationship and role of germline mutations in the carcinogenesis of MGC.

Methods: We gathered 16 multiple gastric cancer patients. Thirty-three tumor samples and sixteen normal gastric tissue or blood samples were obtained from January 2016 to December 2017. We also conducted analyses for 208 gastric cancer and 49 esophagogastric junction cancer (GC-EGJ) tumors from TCGA. DNA extraction from our samples was conducted for whole-exome sequencing (WES).

Results: Tumor mutation burden (TMB) was not statistically significant within database and our data in the GC-EGJ (P=0.0591) and GC groups (P=0.3113). The mutation spectrum and signatures also showed uniform distributions in GC and GC-EGJ groups within our data and TCGA database. Among sixteen patients, four were identified as monoclonal, in which 11, 10, 26 and 6 somatic mutations were shared within different tumors of P7, P8, P9 and P16, respectively. However, no common mutation between different tumors of the same patient was found among the other 12 patients. After identifying predisposing genes, we found that germline MSH2 and NCOR2 mutations were significantly dominant in 8/12 and 10/12 of genetic MGC patients. Additionally, all patients were identified with MSH2 mutations in cancer samples of those genetic MGC patients. Taking genetic MGCs as a whole, we identified that TP53 were significantly mutated in 14 of 25 tumor samples.

Main conclusions: WES analyses are suggestive of monoclonal and polyclonal origin of MGC, which may promote the classification of MGC into genetic and metastatic MGC. For patients with genetic MGC, germline MSH2 X314_splice variants may contribute to carcinogenesis, thus prompting the consideration of more radical surgery and/or anti-PD-1/PD-L1 therapy.

Total Tumor Volume Should be Considered as an Important Prognostic Factor for Synchronous Multiple Gastric Cancer Patients with Curative Gastrectomy

Synchronous multiple gastric cancer (SMGC) was a special type of gastric cancer with relatively low incidence. This article was designed to demonstrate that the total tumor volume (TTV) should be treated as an important prognostic factor in SMGC patients with curative gastrectomy. This study retrospective analyzed 140 SMGC patients who received curative gastrectomy between December 2004 and December 2014 in our hospital. Clinicopathological features, preoperative evaluation, surgical treatment, and outcome parameters were reviewed and analyzed. This study applied univariate and multivariate analyses to identify the most significant prognostic factors. In the univariate analysis, the TTV, pT_TVNM, pN stage, pT of main tumor were all significant prognostic factors in SMGC patients (all P < 0.05). In the multivariate analysis, pN stage, TTV and pT_TVNM were confirmed to be independent prognostic factors (all P < 0.05). In the comparison of survival analysis, the pT_TVNM stage system (P < 0.05) was superior to the pTNM stage system (P > 0.05) in SMGC patients. In conclusion, the TTV should be considered as an independent prognostic factor in overall survival in SMGC patients who received curative gastrectomy. The pT_TVNM stage should be recommended as a suitable staging system for SMGC patients.

Clinicopathological features and impact of adjuvant chemotherapy on the long-term survival of patients with multiple gastric cancers: a propensity score matching analysis

Background

Little is known about the correlation between the clinicopathological features, postoperative treatment, and prognosis of multiple gastric cancers (MGCs). In this study, we aimed to investigate the correlation between these features and the impact of postoperative adjuvant chemotherapy on the long-term survival of patients with MGC.

Methods

The clinical and pathological data of patients diagnosed with gastric adenocarcinoma who had radical gastrectomy from January 2007 to December 2016 were analyzed. Using propensity score matching, the prognostic differences, and the impact of postoperative adjuvant chemotherapy between those with MGC and solitary gastric cancers (SGC) were compared.

Results

Among the 4107 patients investigated, the incidence of MGC was 3.2% (133/4107). Before matching, patients with MGC and SGC had disparities in the type of gastrectomy, pathological tumor stage (pT), pathological node stage (pN), and pathological tumor-node-metastasis stage (pTNM). After a 1:4 ratio matching, the clinical data of 133 cases of MGC and 532 cases of SGC were found to be comparable. The 5-year overall survival (OS) rate was 56.6% in the entire matched cohort, 48.1% in the MGC group, and 58.7% in the SGC group (P = 0.013). Multivariate analysis revealed that MGC, age, pT stage, pN stage, and adjuvant chemotherapy were independent predictors of OS (all P < 0.05). Stratified analyses demonstrated that for the cohort of advanced gastric cancer (AGC) patients who did not had adjuvant chemotherapy, the 5-year OS rate of advanced cases of MGC was inferior than that of SGC patients (34.0% vs. 46.1%, respectively; P = 0.025) but there were no significant difference in the 5-year OS rate between advanced MGC and SGC patients who had adjuvant chemotherapy (48.0% vs. 53.3%, respectively; P = 0.292). Further, we found that the 5-year OS rate of advanced MGC who had adjuvant chemotherapy was significantly higher than those who did not had adjuvant chemotherapy (48.0% vs. 34.0%, P = 0.026).

Conclusions

Patients with advanced MGC was identified as having a poorer survival as to SGC patients, but the implementation of postoperative adjuvant chemotherapy showed that it had the potential to significantly improve the long-term prognoses of MGC patients.

Is endoscopic surveillance necessary for patients who undergo total gastrectomy for gastric cancer?

There have been only a few reports investigating the clinical efficacy of follow-up endoscopy for detection of recurrent gastric cancer after total gastrectomy (TG). We reviewed the records of 747 patients undergoing TG from 2003 to 2012 and enrolled 267 patients (70 with early gastric cancer (EGC) and 197 with advanced gastric cancer (AGC)), who received one or more follow-up endoscopy and contrast abdominal computed tomography (CT) scan. We found no tumor recurrence in the 70 EGC patients during the mean follow-up periods of 42.1 ± 18 and 43.2 ± 19 months by endoscopy and contrast abdominal CT scan. In 197 AGC patients, 59 patients (29.8%) had confirmed tumor recurrence during mean follow-up periods of 40.5 ± 21 and 45.3 ± 22 months. The most common pattern of tumor recurrence was distant metastasis (n = 35) followed by peritoneal metastasis (n = 11). Among the other 13 cases with loco-regional recurrence, seven cases were regional lymph node metastases, four were anastomosis site recurrences, and two were duodenal stump and jejunal loop site recurrences. Three of the four cases of anastomosis site recurrence were found by both endoscopy and contrast abdominal CT scan; one case was missed by contrast abdominal CT scan. However, the two cases with duodenal stump and jejunal loop recurrences were detected by contrast abdominal CT scan only. An annual follow-up endoscopy for gastric cancer after TG might have a limited role in the detection of tumor recurrence, especially in patients with EGC. Contrast abdominal CT scan may be sufficient as a follow-up method for recurrent gastric cancer after TG.

High incidence of other primary malignancies in patients with synchronous multiple gastric cancers "a multi-center retrospective cohort study"

This study evaluated the relationship between synchronous multiple gastric cancer and other primary malignancies. During 2002–2013, 1094 consecutive surgically treated gastric cancer patients were enrolled. Preoperatively, we performed total colonoscopy and whole-body computed tomography. When malignancies in other organs were suspected, detailed organ-specific examinations were performed. Synchronous multiple gastric cancer occurred in 102 patients (9.3%)which was frequently observed in patients with preoperative other primary malignancies (p < 0.001). Preoperative other primary malignancy was an independent risk factor for synchronous multiple gastric cancer (p = 0.001; hazard ratio: 2.145, 95% confidence interval: 1.354–3.399) and an independent prognostic factor of overall survival in patients undergoing gastrectomy with curative intent (p = 0.021; hazard ratio: 1.481, 95% confidence interval: 1.060–2.070). Thus, patients with preoperative other primary malignancies have a high risk of synchronous multiple gastric cancer. Careful preoperative examination is recommended to improve survival.

The 7th AJCC/UICC TNM staging system may be not suitable in predicting prognosis of synchronous multiple gastric carcinoma patients with D2 gastrectomy

To assess the suitability of the 7th AJCC/UICC TNM staging system in predicting the prognosis of synchronous multiple gastric carcinomas (SMGCs). A total of 129 SMGC patients who underwent gastrectomy with D2 lymphadenectomy from January 1999 to January 2009 were enrolled in this study. The location, diameter, and depth of invasion of the main tumor were all related to prognosis (P < 0.05). Multivariate analysis revealed depth of invasion as an independent predictive factor for survival (P < 0.05). Interestingly, logistic regression analysis showed that the 7th AJCC/UICC N staging system was unable to significantly predict survival in SMGCS patients (P > 0.05). Cut-point survival analysis identified the most appropriate cut-offs for metastatic lymph nodes (MLNs) as 0, 1, 6, 10, and 19: patients with 0, 1-6, 7-10, and 11-19, and ≥ 20 MLNs had median survival times of 70, 56, 35, 52, and 32 months, respectively. Multivariate analysis suggested this new categorization of MLNs to be a significant predictor of survival (P < 0.05). Preoperative assessment of depth of invasion can help in the prognosis of SMGCs patients. The 7th UICC TNM staging system may be not suitable for SMGC patients and needs improvement for rational grading of SMGCs.

Characteristics and prognosis of synchronous multiple early gastric cancer

AIM: To assess the clinicopathologic characteristics, risk factors, and prognosis for synchronous multiple early gastric cancer (SMGC).

METHODS: A total of 146 patients with SMGC and 1194 patients with single gastric cancer who had undergone gastrectomy between 1989 and 2008 were retrospectively analyzed to determine their clinicopathologic characteristics and postoperative survival. Tumors were classified into groups on the basis of location and histology. Smoking habits were evaluated using the Brinkman index. Clinical and pathological factors were compared using either Fisher’s exact test or Pearson’s χ² test. Logistic regression analysis was performed to identify independent risk factors. Survival rate was calculated using the Kaplan-Meier method.

RESULTS: SMGCs accounted for 10.9% of gastric cancer cases and occurred predominantly in elderly male patients with a family history of gastric cancer who were both smokers and drinkers. These tumors were typically macroscopically elevated and histologically differentiated. There were no significant differences between SMGC and single gastric cancer patients with respect to tumor location, tumor size, lymph node metastasis, the number of metastatic lymph nodes, venous invasion, or tumor stage (P = 0.052, P = 0.347, P = 0.595, P = 0.805, P = 0.559, and P = 0.408, respectively). Further, there was no significant difference in postoperative survival between the patient groups (P = 0.200). Of the 146 SMGC patients, a single patient had remnant cancer.

CONCLUSION: A careful preoperative endoscopy is necessary for patients who are at high risk of SMGC, and minimally invasive treatment may be indicated in some cases.

How can we predict the presence of missed synchronous lesions after endoscopic submucosal dissection for early gastric cancers or gastric adenomas?

GOALS

To identify predictive factors associated with the presence of missed synchronous lesions after endoscopic submucosal dissection (ESD) for gastric adenoma or early gastric cancer (EGC).

BACKGROUND

Secondary gastric neoplasms that develop during follow-up period after ESD for gastric adenoma or EGC are divided into metachronous lesions and missed synchronous lesions.

METHODS

ESD was performed in 250 patients with EGC or gastric adenoma. The patients with endoscopic follow-ups of <1 year, patients without curative resection, and patients with additional surgery were excluded from the study. Missed synchronous lesions were defined as secondary gastric neoplasms detected within one year of ESD but initially missed. We compared clinicopathologic factors between patients with missed synchronous lesions and patients without missed synchronous lesions.

RESULTS

Missed synchronous lesions were found in 11.6% of the patients (29/250). The occurrence of missed synchronous lesions had significant correlation with tumor number at the time of ESD and age in the univariate analysis. Tumor number at the time of ESD and age were significant independent predictive factors for presence of missed synchronous lesions by multivariate logistic regression analysis (odds ratio 5.302, P = 0.006; odds ratio 2.315, P = 0.040, respectively). Missed synchronous lesions tended to be smaller, often located in the same third of the stomach as the main lesions.

CONCLUSIONS

Tumor number at the time of ESD and age could be predictive factors for the presence of missed synchronous lesions after ESD. Careful endoscopic surveillance should be performed after ESD for multiple lesions or for elderly patients.

Multiple synchronous early gastric cancers: high-risk group and proper management

BACKGROUND

Multiple early gastric cancers (MEGCs) may be easily missed on preoperative gastroscopy because the lesions are predominantly small and flat. This may increase the risks of gastric remnant lesions and recurrence. We aimed to define high-risk group of MEGC and suggest proper management of missed lesion after partial gastrectomy.

METHODS

A total of 117 patients with MEGCs and 2182 with solitary EGC who underwent gastrectomy between 2008 and 2010 were retrospectively analyzed to determine their clinicopathologic characteristics. We also assessed their family history, the presence of Helicobacter pylori infection, and of precancerous lesions; and the results of microsatellite instability and immunohistochemical staining of the primary (largest) lesion for p53, human epidermal growth factor receptor [HER1], and HER2 were also reviewed.

RESULTS

MEGCs occurred more frequently in elderly males and in patients with adenoma, atrophic gastritis, or a family history of gastric cancer. These patients had more favorable pathologic findings, including less deep invasion, better differentiation, more intestinal type, and less frequent lymphovascular/perineural invasion than patients with solitary EGCs. The mean size of MEGCs was smaller (2.44 cm vs 3.36 cm) but there was no difference in the number of metastatic lymph nodes. Most accessory lesions were confined to the mucosal layer, with their average diameter was 1.82 cm.

CONCLUSIONS

A careful preoperative gastroscopy should be performed in patients at high risk of MEGCs and more cautious postoperative endoscopic surveillance of the remnant stomach is required. For missed foci on remnant stomach, endoscopic resection can be a good option if it meets the criteria.

Lymph node metastasis in multiple synchronous early gastric cancer

BACKGROUND

Although endoscopic resection for early gastric cancer (EGC) is increasingly available, it has not been determined whether indications for endoscopic resection are equally acceptable for multiple EGCs.

OBJECTIVE

To compare the various clinicopathologic factors and risk of lymph node (LN) metastasis between multiple and solitary EGCs.

DESIGN

Case-control study.

SETTING

University hospital.

PATIENTS

This study involved 1717 patients with 156 multiple and 1561 solitary EGCs.

INTERVENTION

Gastrectomy with LN dissection.

MAIN OUTCOME MEASUREMENTS

Incidence of LN metastasis.

RESULTS

In multiple EGCs, main lesions had larger tumor size and deeper invasion depth than the accessory lesions (P < .001). The clinicopathologic features of multiple EGCs were similar to those of solitary EGCs with respect to tumor size, depth of invasion, lymphovascular invasion, and incidence of LN metastasis. Importantly, the risk of LN metastasis in multiple EGCs that met the indication criteria for endoscopic resection was not significantly different from that in solitary EGCs. Tumors meeting conventional indications for endoscopic resection had no risk of LN metastasis, whereas tumors meeting expanded indications showed a similar risk of LN metastasis in the two groups. In multiple EGCs, tumor size ≥3 cm and lymphovascular invasion were independent risk factors of LN metastasis.

LIMITATIONS

Small number of patients with multiple EGCs studied.

CONCLUSION

Multiple EGCs had clinicopathologic characteristics and risk of LN metastasis similar to those of solitary EGCs. Endoscopic resection may be adopted as curative treatment for multiple EGCs that meet indications for endoscopic resection. Further studies are needed to verify the present study results.

Epidemiology, pathology and clinical management of multiple gastric cancers: a mini-review

The incidence of multiple gastric cancers (MGCs) has been increasing over the recent decades due to the advance in diagnostic techniques combining with the detailed pathological examinations of surgical resection specimens. Reduction of the surgical extent and trauma under the premise of radical resection improves the quality of life of patients with gastric cancer. However, MGC lesions may have been missed, which can result in adverse consequences. We carried out this systematic review of previous literatures, in order to provide deep insights into epidemiological, pathological and clinical features of MGCs and to establish an efficient way to screen the individuals with high risks. MGCs represent a special type of malignant gastric tumor and possess distinctive features compared with the solitary one. More attention should be paid to both diagnosis and treatment of MGCs. Possibility of overlooking accessory lesions must be kept in mind constantly. For the population at high risk, such as the elderly with differentiated type, strict perioperative tissue examinations and follow-up are essential.

Subtotal gastrectomy as treatment for distal multifocal early gastric cancer

INTRODUCTION

Multifocal early gastric cancer (MEGC) is frequently observed and represents a serious risk when minimally invasive treatments are performed.

PATIENTS AND METHODS

We present the experience of two Italian centers situated in a relatively high incidence area for gastric cancer. Out of a total of 791 surgical resections for EGC carried out in two Italian centers from 1976 to 2006, we identified 98 patients with multifocal EGC (12.3%). Two hundred and sixteen lesions were observed. Generally sited near the principal tumors, secondary lesions were, however, sometimes detected distally from the upper primary lesion. No secondary lesions were detected in the upper third when the principal lesion was sited at the lower third.

RESULTS

Survival of MEGC patients was not significantly lower than that of patients with monofocal EGC. No cases of gastric remnant relapse were observed at a mean follow-up of 9 years (range 1-28) after subtotal gastrectomy.

DISCUSSION

When EGCs are detected, the possibility of MEGC must always be investigated by endoscopy and chromoendoscopy. When a MEGC is found in the lower third of the stomach and chromoendoscopy of the upper third has been performed, subtotal gastrectomy can be considered as sufficient treatment.

Twenty-two metachronous multiple signet-ring cell carcinomas treated with repeated gastrectomies and repeated endoscopic mucosal resections: report of a case

A 45-year-old Japanese woman underwent an endoscopic mucosal resection (EMR) for early gastric cancer at the Cancer Institute Hospital in July 1996. The patient then underwent a distal gastrectomy in 2002 because of a new early gastric cancer and repeated EMR for a total of six early gastric cancers in 2007. Finally, a total gastrectomy was performed in February 2008. The pathological examination of the resected specimen indicated 14 synchronous multiple early gastric cancers. Although the incidence of multiple gastric cancers has been reported to range from 5% to 15%, there is usually only a double or triple lesion. Moreover, multiple gastric cancer is typically observed in male elderly patients as differentiated adenocarcinomas. The present case was a young female patient and all of the lesions were intramucosal signet-ring cell adenocarcinomas. The carcinogenetic mechanism in this case may therefore be different from that in typical multiple gastric cancers. A thorough preoperative examination and regular postoperative follow-up are therefore essential for detecting multiple gastric cancers in their early stages.