Jung Kim

Clinical implications of pre-existing adenoma in endoscopically resected early gastric cancers

Background Although gastric adenoma is widely accepted as a precursor of gastric cancer, pre-existing adenoma is not always detected in gastric cancer patients. Objective To investigate the clinical characteristics of early gastric cancer (EGC) arising from adenoma, compared with those of EGC without pre-existing adenoma. Methods Patients who underwent endoscopic resection for EGC at a single tertiary hospital were divided into two groups based on the presence (ex-adenoma group) or absence (de novo group) of pre-existing adenoma on pathologic specimens. Clinicopathologic characteristics, endoscopic features and long-term outcomes were analyzed. Results Of 1,509 patients, 236 (15.6%) were included in the ex-adenoma group. Mean age (P = 0.003) and Helicobacter pylori infection rate (P = 0.040) were significantly higher in the ex-adenoma than in the de novo group. Mean endoscopic size was significantly larger, elevated lesions were more prevalent (both P < 0.001), and carcinomas were more differentiated in the ex-adenoma group than in the de novo group (P = 0.037). The degree of atrophy (P = 0.025) or intestinal metaplasia (P < 0.001) was more advanced in the ex-adenoma group. Synchronous gastric neoplasia was significantly more prevalent in the ex-adenoma group (P < 0.001), whereas metachronous cancer recurrence rate was not significantly different between the two groups. Conclusions EGCs with pre-existing adenoma show a greater association with H. pylori–related chronic inflammation than those without, which could explain the differences in the characteristics between groups. Potential differences in carcinogenic mechanisms between the groups were explored.

Surveillance strategy according to age after endoscopic resection of early gastric cancer.

BackgroundWhether surveillance strategy after curative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) differs in young patients is unclear. This study aimed to evaluate the risk of metachronous and extragastric recurrence in young patients with EGC after curative ESD.MethodsWe retrospectively enrolled 1237 consecutive patients who underwent curative ESD for EGC from 2005 to 2014 at a single tertiary hospital. The patients were divided into group 1 (<50xa0years of age, nxa0=xa086), group 2 (age 50–74, nxa0=xa0985), or group 3 (≥75xa0years of age, nxa0=xa0166). The clinical characteristics and outcomes were compared among the three age groups.ResultsGroup 1 had more frequent Helicobacter pylori infection (Pxa0<xa00.001), less frequent intestinal metaplasia (Pxa0=xa00.021), and more frequent undifferentiated tumors (Pxa0=xa00.039). Although the 5-year risk of developing metachronous recurrence appeared to be lower in group 1 (2.7%) than in groups 2 (8.6%) or 3 (8.7%), the risk became quite similar at the 7-year follow-up (6.4, 12.7, and 8.7% for groups 1, 2, and 3, respectively; Pxa0=xa00.409 by log-rank test). Extragastric recurrences developed in only 2 cases in group 2 (0.2%).ConclusionsSurveillance for metachronous and extragastric recurrence after curative ESD in patients <50xa0years of age should not be different from that in patients ≥50xa0years of age. Endoscopic surveillance for metachronous recurrence should be continued for longer than 5xa0years, even in young patients.

Long-Term Effects of Helicobacter pylori Eradication on Metachronous Gastric Cancer Development

Background/Aims Gastric mucosal atrophy and intestinal metaplasia due to Helicobacter pylori infection are the main precursor lesions of gastric cancer. The aim of this study was to evaluate the long-term effects of H. pylori eradication on the progression of precancerous lesions to metachronous cancer after endoscopic resection of early gastric cancer (EGC). Methods Patients who underwent endoscopic resection of EGC were retrospectively reviewed. Changes in precancerous lesions and development of metachronous cancer were compared according to H. pylori eradication and final infection status. Results In total, 565 patients were followed for over 5 years after endoscopic resection of EGC. The grade of atrophy on corpus was significantly lower in the H. pylori-eradicated group than in the persistent group during follow-up (p=0.029). In patients <70 years of age, the cumulative incidence rate of metachronous cancer was significantly lower in the H. pylori-eradicated group than in the persistent group (p=0.018). Age was an independent risk factor for metachronous cancer development. Conclusions H. pylori eradication might prevent the development of metachronous cancer in patients <70 years of age by delaying the progression of precancerous lesions after endoscopic resection of EGC.

Continuous Use of Thienopyridine May Be as Safe as Low-Dose Aspirin in Endoscopic Resection of Gastric Tumors

Background/Aims Current guidelines recommend withholding antiplatelets for 5–7 days before high-risk endoscopic procedures. We investigated whether this reduces post-endoscopic submucosal dissection (ESD) bleeding. Methods Gastric ESD cases with antiplatelets were retorospectively reviewed. Withholding antiplatelets for 5–7 days before ESD was defined as cessation and 0–4 days as continuation. The rate and risk of post-ESD bleeding according to the types and cessation of antiplatelets were assessed. Results Among the 215 patients (117 adenoma and 98 early gastric cancer), 161 patients were on single (94 aspirin, 56 thienopyridine, and 11 other agents), 51 on dual, and 3 on triple antiplatelets. Post-ESD bleeding rates were 12.8% in aspirin users, 3.6% in thienopyridine, 27.5% in dual, 33.3% in triple therapy, and 9.7% in the cessation and 15.0% in the continuation group. Multiple antiplatelets (odds ratio [OR], 2.41; 95% confidence interval [CI], 1.01 to 5.76) and specimen size ≥ 5.5 cm (OR, 2.84; 95% CI, 1.04 to 7.73) were the risk of bleeding, while continuation of thienopyridine (OR, 0.23; 95% CI, 0.05 to 1.09) and antiplatelets (OR, 1.83; 95% CI, 0.68 to 4.94) did not increase the risk of bleeding. Conclusions Continuing thienopyridine and aspirin did not increase the risk of post-ESD. Multiple antiplatelet therapy and a large specimen size were independent risk factors of post-ESD bleeding.

Novel risk stratification for metachronous recurrence after curative endoscopic submucosal dissection for early gastric cancer

BACKGROUND AND AIMSnThis study stratified the risk of developing metachronous gastric cancer (MGC) after curative endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) to enable customization of endoscopic surveillance for MGC.nnnMETHODSnA total of 1115 patients who underwent curative ESD based on the expanded criteria for differentiated EGC from 2005 to 2014 at a single tertiary hospital were enrolled in this retrospective cohort study. They were followed up with annual endoscopy for a median of 50.1 months. Helicobacter pylori and histologic intestinal metaplasia (IM) were evaluated. The Kaplan-Meier method and Cox regression analysis were used for risk stratification.nnnRESULTSnThree risk groups were identified: group 1 comprised patients with a synchronous neoplasm; group 2 comprised male patients with corpus IM; and group 3 comprised male patients without corpus IM or female patients. The 5- and 7-year cumulative risks (95% confidence interval [CI]) for metachronous recurrence were 15.1% (95% CI, 7.7-22.5) and 26.1% (95% CI, 14.9-37.3), respectively, in group 1; 5.6% (95% CI, 3.1-8.1) and 9.3% (95% CI, 5.4-13.2), respectively, in group 2; and 3.8% (95% CI, 1.6-6.0) and 4.9% (95% CI, 2.4-7.4), respectively, in group 3 (Pxa0< .001 by log-rank test). The incidence of MGCs increased constantly even after 5 years in groups 1 and 2 but not in group 3. There was not enough evidence to show an association between H pylori eradication and metachronous recurrence in the data.nnnCONCLUSIONSnMeticulous annual endoscopic surveillance for MGC for more than 5 years is recommended for patients with synchronous neoplasm. Endoscopic surveillance may also be extended beyond 5 years in male patients with corpus IM.

Clinical efficacy of endoscopic ultrasonography for decision of treatment strategy of gastric cancer

BackgroundAccurate preoperative tumor staging of gastric cancer is indispensable with expansion of indications for laparoscopic surgery and endoscopic resection. It is important to distinguish mucosal cancer (T1a) in smaller lesion and differentiate early gastric cancer (EGC) in larger lesion considering endoscopic resection indication and laparoscopic surgery indication. We evaluated the clinical outcomes of endoscopic ultrasonography (EUS) for the decision of treatment strategy of gastric cancer compared with pathological staging.MethodsThe patients who underwent EUS and surgical or endoscopic resection for gastric cancer were retrospectively reviewed between September 2005 and February 2016. The depth of tumor invasion (T staging) by EUS was compared with the pathological staging after endoscopic or surgical resection.ResultsA total of 6084 patients were finally analyzed. The accuracy rates for T1a and EGC were 75.0 and 89.4%, respectively. The overall accuracy of T staging by EUS was 66.3% when divided by T1a, T1b, and over T2. The accuracy of EUS prior to endoscopic resection was 75.1% in absolute indication and 73.1% in expanded criteria, respectively. The accuracy rates for T1a with lesion ≤u20092xa0cm in miniprobe EUS and EGC with lesion >u20092xa0cm in conventional EUS were 84.6 and 83.2%, respectively. In multivariate analysis, presence of ulcer, large tumor size, and radial EUS were associated with overestimation, and small tumor size and miniprobe were associated with underestimation in T staging.ConclusionsEUS showed the high accuracy of 84.6% for T1a in lesion ≤u20092xa0cm in miniprobe EUS and 83.2% for EGC in lesion >u20092xa0cm in conventional EUS, respectively. EUS can be a complementary diagnostic method to determine endoscopic or surgical treatment modality.

Risk factors for early metachronous tumor development after endoscopic resection for early gastric cancer

Background Metachronous gastric tumor (MGT) is one of major concerns after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). Optimal follow-up strategy has not been yet well-established. The aim of this study was to identify the different clinical features of the patients according to the time interval to development of MGT. Methods Among 1,780 consecutive patients with EGC who underwent ESD between 2005 and 2014, 115 patients with MGT were retrospectively reviewed. MGT was defined as secondary gastric cancer or dysplasia detected > 1 year after initial ESD. Clinicopathological factors associated with early development of MGT were evaluated. Results The median interval to development of MGT was 37 months. In univariate analysis, the median interval to MGT was shorter if EGC lesion was non-elevated type (39.4 vs 57.0 months, p = 0.011), or synchronous primary lesion was absent (39.8 vs 51.4 months, p = 0.050). In multivariate Cox’s proportional hazards analysis, the hazard ratios for early occurrence of MGT were 1.966 (95% CI: 1.141–3.386, p = 0.015) and 1.911 (95% CI: 1.163–3.141, p = 0.011), respectively. There was no significant difference in overall survival after diagnosis of MGT between the early occurrence group and the late occurrence group. Conclusions Non-elevated gross type and absence of synchronous gastric tumor were independent risk factors for early development of MGT. Meticulous endoscopic inspection is especially important for the detection of MGT during the early follow-up period in patients with these initial tumor characteristics.