Multi-disciplinary team for early gastric cancer diagnosis improves the detection rate of early gastric cancer

The Digestive Endoscopy Center of Affiliated Hospital of Zunyi Medical College is one of the largest endoscopy centers in China that meets international standards. Approximately 30,000 gastroscopies were performed annually during the past three years. The endoscopists in the Center are all skilled in endoscopic diagnosis and treatment, and each endoscopist has an experience performing over 3000 gastroscopic examinations.

MDT for diagnosis and treatment of EGC was established in September 2014, which contains the Departments of Digestive Endoscopy Center, Gastroenterology, Gastrointestinal Surgery, Anesthesiology, and Pathology. The discussion meeting of EGC MDT was held once a month. Digestive Endoscopy Center, Department of Gastroenterology and Department of Pathology were the main members of MDT meeting. The measures of MDT were as follows. First, endoscopists were trained through lectures, watching photos and videos, on-site teaching, and participating discussion meeting for EGC patients in the Center once a week to enhance their awareness and ability to identify EGC. Two senior endoscopists (HuihaoWu and Lianjun Di) made intensive gastroscopies for high-risk patients of gastric cancer (ie, those with atrophic gastritis, gastric ulcer, stomach surgery history, and first-degree relatives of gastric carcinoma patients). During this process, painless and comfortable gastroscopy was made to facilitate careful examination; mucus decomposing, antifoaming and spasmolytic agents were used to improve the visibility of the gastric mucosa; and standardized gastroscopy photography, white light endoscopy (WLE) indigo carmine staining, narrow band imaging (NBI), and magnifying endoscopy were performed to improve the detection of EGC. Secondly, the Center strengthened the cooperation with Department of Gastroenterology. The gastroenterologists in outpatient service screened high-risk patients of gastric cancer, and then the endoscopist made intensive gastroscopies for the high risk patients. It is most important to use a magnifying endoscopy for intensive gastroscopy. Magnifying endoscopy with narrow-band imaging (M-NBI) can make suspicious lesions more visible. The magnifying endoscopic diagnosis of EGC was determined according to the vessel plus surface (VS) classification system, including an irregular microvascular and/or microsurface pattern together with a clear demarcation line [18]. Thirdly, a regular communication and discussion for the diagnosis of EGC patients between endoscopist and pathologist was made once a week. Fourthly, strengthening cooperation with Department of Gastrointestinal Surgery, all patients with gastric carcinoma who were not suitable for endoscopic submucosal dissection (ESD) were discussed multidisciplinarily within one week to determine the scope and grade of the lesion and operation way. For the patient diagnosed as gastric cancer for many times by endoscopist, but repeated biopsies did not support the diagnosis of gastric cancer, multidisciplinary discussion made a decision whether it needs further surgery. Finally, strengthening cooperation with Department of Anesthesiology, painless endoscopy can eliminate the patient’s fear, avoid nausea and vomiting reaction, and slow gastric peristalsis, which is contributive to further intensive gastroscopy for suspicious lesions.

All gastroscopies performed from September 1, 2013 to September 1, 2015 were reviewed. The study was divided into 2 periods, period 1 (September 1, 2013 to August 31, 2014) and period 2 (September 1, 2014 to September 1, 2015) according to the time of MDT establishment. The endoscopists to undergo endoscopy were same during the two periods. Pathological diagnosis for EGC was performed by gastrointestinal pathologists according to the revised Vienna classification [19]. Mucosal high-grade neoplasia (including high-grade adenoma/dysplasia), noninvasive carcinoma (carcinoma in situ), suspicious for invasive carcinoma, and intramucosal carcinoma were diagnosed as EGC. The diagnosis of EGC before MTD (period 1) was determined by endoscopist according to endoscopic and histological examinations, without collaboration and communication of MDT. The EGC detection rates before and during MDT were compared. The factors affecting the detection of EGC were analyzed by two endoscopists (HC.W. and LJ.D.). This study was approved by the ethics committee of Zunyi Mecial College, and all patients provided written informed consent for the procedures before endoscopy.

Demographic and clinical characteristics of all patients were evaluated, including age, gender, status (outpatient/inpatient), gastrointestinal symptoms such as abdominal pain and vomiting, past medical history (mainly atrophic gastritis, gastric ulcer), and whether first-degree relatives of gastric carcinoma patients. Endoscopic characteristics to be assessed in the patients with EGC included the site and general morphology of the lesion, surface microstructure, and vascular characteristics.

Statistical analysis was processed by using the SPSS PC statistic package. The age with mean ± standard deviation was evaluated using independent samples t test. The Pearson Chi-Square (χ ² ) test was applied for the detection rates of EGC between different cooperation departments, sex ratio, and ratio of inpatient and outpatient before and during MDT. The factors affecting the detection of EGC were assessed by univariate and multivariate logistic analyses. Odds ratio (OR) and 95% confidence intervals (CIs) were determined for significant variables found on multivariate analysis. P < 0.05 was considered statistically significant.

From September 1, 2013 to September 1, 2015, the gastroscopies of a total of 60,800 patients were performed in the Digestive Endoscopy Center of Affiliated Hospital of Zunyi Medical College. Among 60,800 patients, 61 patients (0.1%) were diagnosed as EGC, accounting for 16.44% of total 371 diagnosed gastric cancer patients during this period. The EGC detection rate by endoscopists before MDT was 0.05%, accounting for 9.09% of the all diagnosed gastric cancer patients during the period 1. In contrast, the EGC detection rate during MDT was 0.15%, accounting for 23% of the all diagnosed gastric cancer patients during the period 2 (Table 1).

As shown in Table 2, among the 61 EGCs, 4 were located at the gastric fundus, 3 at the lesser curvature of the gastric corpus, 7 at the greater curvature of the gastric corpus, 4 at the posterior of the gastric corpus, 1 at the anterior of the gastric corpus, 13 at the gastric angle, and 29 at the gastric antrum. 1 was protruding type (0-I), 10 were surface protruding type (0–IIa), 15 were surface depressed type (0–IIc), 2 were flat type (0–IIb), 20 were mixed type (0–IIa + IIc), 2 were mixed type (0–IIc + IIa), and 11 were depressed type (0–III). In general, EGC has various morphological characteristics and the lesion is very subtle. Among the 61 EGCs, images of 24 cases are shown in Fig. 1, including the general morphology of the lesion under the white light imaging (WLI) for these EGCs.

Figure 2 shows endoscopic and histopathologic images of 6 typical EGCs, classified as 0–IIa (A), 0–IIb (B), 0–IIc (C), and 0–IIa + IIc (D, E, F) lesions, respectively. Representative endoscopic and histopathologic images of other patients with EGC are shown in Additional file 1 and Additional file 2. Among the 6 EGCs, 4 were located at the gastric antrum, 2 were located at the gastric corpus and all had typical appearance on M-NBI, including an irregular microvascular and an irregular microsurface pattern with a demarcation line. Pathological examinations of ESD- or surgery-resected specimens showed that there was high-grade intraepithelial neoplasia, signet ring cell carcinoma, or moderately- differentiated adenocarcinoma in these patients.

During September 2013 to September 2015, 60,800 gastroscopies were performed at our center, 2594 patients were underwent biopsies and 620 patients were diagnosed as low-grade intraepithelial neoplasia. Before MDT, from September 1, 2013 to August 31, 2014, 29,043 gastroscopies were performed, 1152 patients were underwent biopsies, and 253 patients were diagnosed as low-grade intraepithelial neoplasia. 33 patients were suspected EGC under white light imaging (WLI) among 253 patients. After repeatedly biopsies, only 2 patients were diagnosed as EGC. Pathological examination of ESD- or surgery resected specimens showed that 1 was well-differentiated adenocarcinoma and 1 was poorly-differentiated adenocarcinoma. During MDT, from September 1, 2014 to September 1, 2015, 31,397 gastroscopies were performed, 1442 patients were underwent biopsies, and 397 patients were initially diagnosed low-grade intraepithelial neoplasia. 38 patients were suspected EGC under WLI among the 397 patients, and after repeatedly targeted biopsies under M-NBI, 21 patients were diagnosed as high-grade intraepithelial neoplasia and 1 patient was diagnosed as signet ring cell carcinoma among the 38 patients by cooperative consultation with Department of Pathology. Finally, 21 patients with high-grade intraepithelial neoplasia were resected with ESD and 1 patient of signet ring cell carcinoma was treated by surgery. The detection rate of EGC in the low-grade intraepithelial neoplasia was markedly increased from 0.7% to 5.9% before and after cooperation with Department of Pathology (Fig. 3).

Before cooperation with Department of Gastrointestinal Surgery, tissue biopsies were obtained repeatedly from 11 patients with typical characteristics of the advanced gastric cancer under WLI, and pathological examination showed that all were low-grade intraepithelial neoplasia. Only 2 patients were treated and confirmed as EGC with advanced gastric cancer appearance. After cooperation with Department of Gastrointestinal Surgery, there are 10 patients with typical characteristics of the advanced gastric cancer under WLI, but pathological examination showed low-grade intraepithelial neoplasia. 6 patients were treated and confirmed as EGC with advanced gastric cancer appearance by consultation with Department of Gastrointestinal Surgery. The detection rate of EGC in the low-grade intraepithelial neoplasia was markedly increased from 0.7% to 1.6% before and after cooperation with Department of Gastrointestinal Surgery.

After high-risk patients of gastric cancer were screened by the gastroenterologists at outpatient service, endoscopists further made intensive gastroscopy for the high risk patients. The detection rate of EGC in high-risk patients by intensive gastroscopy was 3.3%, whereas the detection rate of EGC only by white light endoscopy was 0.5% (Fig. 4). Further results by univariate and multivariate logistic analyses showed that the cooperation with Department of Pathology (OR = 10.1, 95% CI 2.39–43.3, P < 0.05) and intensive gastroscopy for high-risk patients (OR = 28.3, 95% CI 19.6–40.7, P < 0.001) were independently associated with the detection of EGC. Intensive gastroscopy for high risk patients of gastric cancer enhanced the detection rate of EGC in cooperation with Department of Pathology. Moreover, 899 of 31,397 (2.8%) gastroscopies were performed under intensive gastroscopy during MDT, compared with 30 of 29,013 (0.1%) gastroscopies before MDT. There were no significant differences in gender and age of patients, tissue biopsy rate, the number of high-risk patients, and the number of painless gastroscopy before and during MDT (Table 3).