Outcomes of Endoscopic Resection for Early Gastric Cancer in Very Elderly Patients: A Nationwide Population-Based Study.

Background/Aims: 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 to 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 sex. 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 and cancer-specific survival 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 cancer-specific survival. A significantly decreased risk for mortality was observed in all groups (p<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. Furthermore, the 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 overall survival comparable to that of the control group.

Interval Advanced Gastric Cancer After Negative Endoscopy.

BACKGROUND & AIMS: Esophagogastroduodenoscopy (EGD) is effective in reducing gastric cancer mortality through detection of early-stage cancer in areas with a high prevalence of gastric cancer. Although the risk of post-endoscopy advanced gastric cancer (AGC) is low, interval AGC remains a concern. We investigated the characteristics and predictors of interval AGC after negative EGD. METHODS: We included 1257 patients with gastric cancer within 6 to 36 months of a "cancer-negative" index EGD between 2005 and 2021 at a tertiary university hospital in South Korea. Observation time on the index EGD was used as a quality indicator. We compared the clinical and endoscopic characteristics and quality indicators between interval AGC and screen-detected early gastric cancer (EGC). RESULTS: Within 6 to 36 months of negative EGD, 102 AGCs (8.1%) and 1155 EGCs (91.9%) were identified. The percentage of patients with shorter observation time (<3 minutes) in the index EGD was higher in the interval AGC group than in the detected EGC group (P = .002). A multivariable analysis comparing screen-detected EGD and interval AGC was adjusted for age, sex, family history of gastric cancer, H. pylori status, endoscopic findings, and endoscopy-related factors including gastric observation time and interval time. A shorter observation time (<3 minutes) (odds ratio, 2.27; 95% confidence interval, 1.20-4.30), and interval time >2 years (odds ratio, 1.84; 95% confidence interval, 1.04-3.24) were associated with an increased risk of interval AGC. CONCLUSION: A shorter observation time during index EGD is an important predictor of interval AGC. Further, withdrawal time longer than 3 minutes may be a quality indicator for screening EGD.

Proton pump inhibitors use and the risk of fatty liver disease: A nationwide cohort study.

BACKGROUND AND AIM: Proton pump inhibitor (PPI)-induced hypochondria can change the composition of the gut microbiota, inducing overgrowth of small bowel bacteria, which has been suggested to promote the development of fatty liver disease through the gut-liver axis. In this study, we aimed to investigate the association between PPI use and the risk of fatty liver disease. METHODS: A retrospective cohort study was conducted using the Korean National Health Insurance Service-National Sample Cohort, a nationwide population-based representative sample, from January 1, 2002, to December 31, 2015. PPI use was identified from treatment claims and considered as a time-varying variable. RESULTS: During 1 463 556 person-years of follow-up, 75 727 patients had at least one PPI prescription, and 3735 patients developed fatty liver disease. The hazard ratio for fatty liver disease comparing PPI users with non-PPI users was 1.68 (95% confidence interval, 1.61-1.75). When adjusted for multiple confounders, including age, sex, body mass index, smoking, alcohol intake, exercise, income level, and comorbidities, the association was still significant (hazard ratio, 1.50; 95% confidence interval, 1.44-1.57). After considering the amounts of PPIs stratified by cumulative defined daily dose, the dose-response effect was observed until 180 days. Subgroup analysis also revealed that PPI use was correlated to an increased risk of fatty liver disease. CONCLUSIONS: This current national wide cohort study suggests that PPI use was associated with an increased risk of fatty liver disease compared with non-use of PPIs. Clinicians should consider fatty liver as a potential risk when prescribing PPI.

[Impact of Sarcopenia on the Risk of Erosive Esophagitis].

Background/Aims: An association between obesity and erosive esophagitis has been reported, but the effects of sarcopenia and obesity on erosive esophagitis are unknown. This study examined the relationship between obesity, sarcopenia, sarcopenic obesity, and erosive esophagitis in a large population of asymptomatic men and women. Methods: This study analyzed 32,762 subjects who underwent a comprehensive health check-up, which included upper gastrointestinal endoscopy, from August 2006 to December 2011 by a cross-sectional study. Sarcopenia was defined as a decrease in the appendicular skeletal muscle mass (ASM)/body weight value of two SD or more below the normal means for a younger reference group. Results: The study was carried out on four groups according to obesity and sarcopenic status: normal, obesity, sarcopenic, and sarcopenic obese group. In a multivariable model, the risk of erosive esophagitis was higher in the obese (adjusted OR [aOR] 1.35, 95% CI 1.22-1.49), sarcopenic (aOR 2.12, 95% CI 1.40-3.19), and sarcopenic obese groups (aOR 1.54, 95% CI 1.27-1.87) than in the normal group. The risk of erosive esophagitis was higher in the sarcopenic and sarcopenic obese groups than the obese group; the ORs were 1.63 (95% CI 1.08-2.47) and 1.22 (95% CI 1.01-1.46), respectively. In dose-response analysis, increasing sarcopenia severity showed a positive and graded relationship with the overall, Los Angeles (LA)-B or higher grade, and LA-C erosive esophagitis. Conclusions: This study suggests that sarcopenia is strongly and progressively associated with erosive esophagitis.

Lack of Association between Past Helicobacter pylori Infection and Diabetes: A Two-Cohort Study.

Helicobacter pylori (H. pylori) may be involved in diabetes and other insulin-related processes. This study aimed to investigate the associations between H. pylori infection and the risks of type 2 diabetes, impaired glucose tolerance (IGT), diabetic nephropathy, and poor glycemic control. We retrospectively evaluated 16,091 subjects without diabetes at baseline who underwent repeated health examinations. Subjects were categorized according to whether they were seropositive and seronegative for H. pylori infection. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazard models. The serological results were validated using an independent cohort (n = 42,351) based on a histological diagnosis of H. pylori infection. During 108,614 person-years of follow-up, 1338 subjects (8.3%) developed newly diagnosed diabetes, although the cumulative incidence of diabetes was not significantly related to serological H. pylori status. The multivariate Cox proportional-hazards regression models revealed that H. pylori seropositivity was not significantly associated with diabetes (HR: 1.01, 95% CI: 0.88-1.16; p = 0.854), IGT (HR: 0.98, 95% CI: 0.93-1.04; p = 0.566), diabetic nephropathy (HR: 0.99, 95% CI: 0.82-1.21; p = 0.952), or poor glycemic control (HR: 1.05, 95% CI: 0.90-1.22; p = 0.535). Similarly, histopathological findings of H. pylori infection were not significantly associated with diabetes (p = 0.311), diabetic nephropathy (p = 0.888), or poor glycemic control (p = 0.989). The findings from these large Korean cohorts indicate that there does not appear to be a role for past H. pylori infection in the development of diabetes, IGT, diabetic nephropathy, or poor glycemic control.

Obesity and Risk of Peptic Ulcer Disease: A Large-Scale Health Check-Up Cohort Study.

The association between obesity and peptic ulcer disease (PUD) is inconclusive. To evaluate the association of obesity and metabolically healthy obesity (MHO) with PUD risk, we performed a retrospective cohort study of 32,472 subjects without PUD at baseline who underwent repeated health examinations. Participants were stratified by body mass index (BMI) and metabolically healthy state. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazard modelling. During the follow-up period, 1940 PUD cases occurred. PUD, particularly gastric ulcer (GU), had significantly higher cumulative incidence in obese subjects compared to non-obese subjects (p value < 0.001). The HR for developing GU was 1.32 (95% CI, 1.16-1.49; p value <0.001); after adjusting for confounding factors (lifestyle, metabolic, and Helicobacter pylori status), the association was no more significant (p value = 0.789). For duodenal ulcer (DU), cumulative incidence between obese and non-obese groups was not significantly different (p value = 0.464). The risk of developing DU in the obese group was not significantly different from the non-obese group (HR 0.95; 95% CI, 0.83-1.09; p value = 0.469) and consistently showed no association after adjusting for metabolic parameters (p value = 0.199). Furthermore, MHO subjects had no increase in GU or DU risks. In this large cohort study, PUD risk was not associated with obesity or MHO.

Application of Efficient Data Cleaning Using Text Clustering for Semistructured Medical Reports to Large-Scale Stool Examination Reports: Methodology Study.

BACKGROUND: Since medical research based on big data has become more common, the community's interest and effort to analyze a large amount of semistructured or unstructured text data, such as examination reports, have rapidly increased. However, these large-scale text data are often not readily applicable to analysis owing to typographical errors, inconsistencies, or data entry problems. Therefore, an efficient data cleaning process is required to ensure the veracity of such data. OBJECTIVE: In this paper, we proposed an efficient data cleaning process for large-scale medical text data, which employs text clustering methods and value-converting technique, and evaluated its performance with medical examination text data. METHODS: The proposed data cleaning process consists of text clustering and value-merging. In the text clustering step, we suggested the use of key collision and nearest neighbor methods in a complementary manner. Words (called values) in the same cluster would be expected as a correct value and its wrong representations. In the value-converting step, wrong values for each identified cluster would be converted into their correct value. We applied these data cleaning process to 574,266 stool examination reports produced for parasite analysis at Samsung Medical Center from 1995 to 2015. The performance of the proposed process was examined and compared with data cleaning processes based on a single clustering method. We used OpenRefine 2.7, an open source application that provides various text clustering methods and an efficient user interface for value-converting with common-value suggestion. RESULTS: A total of 1,167,104 words in stool examination reports were surveyed. In the data cleaning process, we discovered 30 correct words and 45 patterns of typographical errors and duplicates. We observed high correction rates for words with typographical errors (98.61%) and typographical error patterns (97.78%). The resulting data accuracy was nearly 100% based on the number of total words. CONCLUSIONS: Our data cleaning process based on the combinatorial use of key collision and nearest neighbor methods provides an efficient cleaning of large-scale text data and hence improves data accuracy.

Physical Activity Protects Against the Risk of Erosive Esophagitis on the Basis of Body Mass Index.

GOAL: To determine whether physical activity lowers the risk for erosive esophagitis on the basis of body mass index (BMI). BACKGROUND: Although previous studies have shown that physical activity is closely associated with erosive esophagitis, these data may be confounded by obesity. STUDY: In this retrospective study, we included 182,409 patients who underwent an upper endoscopy and were diagnosed with erosive esophagitis. The impact of the amount and intensity of physical activity on the risk for erosive esophagitis was analyzed based on BMI groups. Subjects were classified into three BMI groups with equal numbers in each group. RESULTS: Overall, 10.3% (n=18,859) of patients were diagnosed with erosive esophagitis. After adjusting for confounding factors, a greater amount of exercise [lower tertile: odd ratio (OR), 0.86; 95% confidence interval (CI), 0.77-0.96; middle tertile: OR, 0.91; 95%, CI 0.84-1.00; upper tertile: OR, 0.79; 95% CI, 0.73-0.85) and increased exercise intensity (lower tertile, moderate: OR, 0.61; 95% CI, 0.52-0.71; vigorous: OR, 0.51; 95% CI, 0.44-0.58; middle tertile, moderate: OR, 0.62; 95% CI, 0.55-0.70; vigorous: OR, 0.58; 95% CI, 0.51-0.65; upper tertile, moderate: OR, 0.58; 95% CI, 0.53-0.65; vigorous: OR, 0.58; 95% CI, 0.53-0.64) was associated with a decreased risk for erosive esophagitis in all 3 BMI groups. In addition, we observed that increased physical activity intensity notably decreased the risk for erosive esophagitis in subjects performing lesser physical activity, but slightly decreased the risk for erosive esophagitis in subjects performing more physical activity. CONCLUSION: Physical activity is inversely associated with erosive esophagitis.

Impact of sarcopenia on the risk of advanced colorectal neoplasia.

BACKGROUND AND AIM: Sarcopenia is a pathological condition characterized by the progressive loss of muscle mass and increased amount of visceral fat. Recent evidence has revealed that sarcopenia is associated with certain diseases. However, the impact of sarcopenia on colorectal neoplasia has not been documented clearly. We studied the association between sarcopenia and advanced colorectal neoplasia in a large screening population. METHODS: This cross-sectional study included 14 024 asymptomatic adults who underwent first-time screening colonoscopy. Sarcopenia (class II) was defined as an appendicular skeletal muscle mass (ASM)/bodyweight (%) value more than two standard deviations below the mean for healthy young adults. ASM was estimated using bioelectrical impedance analysis. RESULTS: In a multivariable model adjusted for age, sex, obesity (body mass index ≥ 25), smoking status, alcohol intake, regular exercise, and family history of colorectal cancer, the odds ratio (OR) for advanced colorectal neoplasia on comparing participants with sarcopenia (class II) to those without sarcopenia (class I + II) was 1.52 (95% confidence interval [CI], 1.23-1.86). Further adjustment for metabolic parameters attenuated this association, but the association was still significant (OR, 1.34; 95% CI, 1.07-1.68). Furthermore, the multivariable (traditional risk factors)-adjusted OR associated with a 1% decrease on the introduction of ASM/weight% as a continuous variable in regression models was 1.04 (95% CI, 1.01-1.07) for advanced colorectal neoplasia. CONCLUSIONS: Our findings indicate that sarcopenia is significantly and progressively associated with the risk of advanced colorectal neoplasia. This association might be explained by metabolic factors that could be potential mediators of the effect of sarcopenia.

Feasibility of Endoscopic Resection in Early Gastric Cancer with Lymphovascular Invasion.

BACKGROUND: Lymphovascular invasion (LVI) is associated with the risk of lymph node metastasis (LNM) and poor survival in gastric cancer patients; however, it is unclear whether LVI is a non-curative criteria component in all patients. We evaluated the risk factors of LNM in LVI-positive early gastric cancer (EGC) patients and identified a subgroup with a negligible LNM risk to assess the feasibility of endoscopic resection in these patients. METHODS: The clinicopathologic and survival data of patients undergoing surgery for gastric cancer were reviewed; LVI-positive EGC patients were selected. Logistic regression analysis was used to test the associations of potential risk factors with LNM, and Kaplan-Meier analysis was used to compare survival curves. RESULTS: LVI was detected in 1243 (15.5%) patients. In the multivariate logistic analysis, larger tumor size (odds ratio [OR] 1.23, 95% confidence interval [CI] 1.16-1.31; p < 0.001), presence of ulcer (OR 1.80, 95% CI 1.15-2.82; p = 0.010), undifferentiated histology (OR 1.64, 95% CI 1.25-2.16; p < 0.001), submucosal invasion (OR 2.28, 95% CI 1.38-3.76; p = 0.001), middle (OR 2.12, 95% CI 1.26-3.55; p = 0.004) or lower third location (OR 2.28, 95% CI 1.32-3.60; p = 0.002), and younger age (OR 0.98, 95% CI 0.97-0.99; p = 0.002) independently predicted LNM in LVI-positive EGC patients. LVI-positive patients fulfilling the absolute endoscopic resection criteria did not have LNM and there was no significant difference in the overall (p = 0.928) and disease-specific survival (p = 0.821) between these patients and those with LVI-negative EGC. CONCLUSIONS: Additional surgery after endoscopic resection might be unnecessary in LVI-positive patients meeting the absolute criteria for endoscopic resection.

Effect of age on the clinical outcomes of patients with early gastric cancer with undifferentiated-type histology.

BACKGROUND: Undifferentiated-type early gastric cancers account for a large proportion of gastric cancers in younger patients. Therefore, the clinical outcomes of endoscopic resection in younger patients are a major concern. We aimed to investigate the influence of age on lymph node metastasis and long-term survival after surgery for undifferentiated-type early gastric cancers. METHODS: We identified 4,236 patients who underwent surgery for undifferentiated-type early gastric cancers. For each T stage, the correlation between age and lymph node metastasis was analyzed using a multivariate logistic regression. Lymph node metastasis rates were compared between younger (<40 years) and older patients (≥40 years) who fulfilled the expanded criteria for endoscopic resection. The Kaplan-Meier method was used to compare long-term survival between younger and older patients. RESULTS: Younger age groups (20-29 and 30-39 years) had the highest lymph node metastasis rate within each T stage (5.7% and 5.7% for T1a, 26.3% and 24.1% for T1b, respectively). After adjusting for possible covariates, however, age did not have a significant effect on lymph node metastasis in either T stage (P = .127 for T1a, P = .114 for T1b). Among patients fulfilling the expanded indication for endoscopic resection, younger patients had a slightly higher lymph node metastasis rate compared with older patients (2.7% versus 2.0%), although this difference was not statistically significant. Although younger patients had a significantly better overall survival (P < .001), no significant age-related differences were observed in recurrence-free and disease-specific survival (P = .051 and P = .069) CONCLUSION: Endoscopic resection may be feasible in young patients with undifferentiated-type early gastric cancers because these patients share a similar lymph node metastasis rate and long-term survival outcomes with older patients.

Young Age and Risk of Lymph Node Metastasis in Differentiated Type Early Gastric Cancer.

BACKGROUND: Young patients with gastric cancer reportedly have a worse prognosis than older patients due to delayed diagnosis and more aggressive tumor behavior. However, it is unclear whether this applies to early gastric cancer (EGC), for which endoscopic resection is indicated. We investigated the association between age and lymph node metastasis (LNM). METHODS: We identified 4055 patients diagnosed with EGC of differentiated histology who underwent surgery. The association between age and LNM was examined using logistic regression for each T stage separately with adjustments for multiple covariates. We compared LNM rates for each of the Japanese Endoscopic Resection Guidelines criteria in younger (< 40 years) and older patients (40 years). RESULTS: The median number of lymph nodes examined was the same for T1a and T1b stages (n = 34). The median number of lymph nodes examined was not significantly different within T1a stage (P = 0.093), but within T1b stage, the number of lymph nodes examined was significantly different (P = 0.019). The highest number was between 50 and 59 years (median = 37), and the lowest number was in the 20 to 49 years and older than 70 age brackets (median = 34). LNM rate and age were not significantly associated within each stage (P values 0.269, 0.783 for T1a and T1b, respectively). Among patients fulfilling endoscopic resection criteria, the LNM rate in younger patients was lower than in older patients. CONCLUSIONS: In differentiated-type EGC, young age at diagnosis was not associated with LNM rate. Therefore, endoscopic resection criteria for early gastric cancer can be applied to younger patients.

Lack of Association between Helicobacter pylori Infection and Various Markers of Systemic Inflammation in Asymptomatic Adults.

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) infection has been known to cause various extra-gastric diseases, which may be mediated by an increase in systemic inflammation. Thus, we examined the association between H. pylori infection and various markers of systemic inflammation in a large sample of asymptomatic adults. METHODS: Cross-sectional data were obtained from 17,028 adults who completed routine health check-ups. H. pylori infection status was determined using a serum immunoglobulin G test, and systemic inflammation was assessed using the C-reactive protein (CRP) levels, neutrophil/lymphocyte ratio (NLR), and platelet/lymphocyte ratio (PLR). RESULTS: Multiple linear regression model-adjusted for potential confounders-revealed that H. pylori infection was not associated with CRP levels (coefficient: -0.012, 95% confidence interval [CI]: -0.037, 0.012, p=0.319), NLR (coefficient: 0.055, 95% CI: -0.027, 0.138, p=0.192), or PLR (coefficient: 1.798, 95% CI: -1.979, 5.574, p=0.351). In a multivariable logistic regression model, H. pylori infection was not associated with the risk of CRP levels being elevated to ≥0.1 mg/dL (odds ratio: 0.96, 95% CI: 0.81, 1.08) or ≥0.3 mg/dL (odds ratio: 1.02, 95% CI: 0.84, 1.19). In the multivariable model, CRP levels elevated to ≥0.1 mg/dL were significantly associated with body mass index, current smoking status, hypertension, and diabetes mellitus. Regular exercise and high-density lipoprotein cholesterol were factors that minimized the elevation of CRP levels. CONCLUSIONS: Chronic infection with H. pylori was not associated with various inflammatory markers. Further investigation is needed to clarify the interaction between H. pylori infection, systemic inflammation, and extra-gastric disease.

Identification of risk factors for sessile and traditional serrated adenomas of the colon by using big data analysis.

BACKGROUND AND AIM: Little is known about the risk factors associated with serrated polyps, because the early studies, which occurred before the new World Health Organization classification was introduced, included mixtures of serrated polyps. This study aimed to evaluate the risk factors associated with the presence of sessile serrated adenomas (SSAs) and traditional serrated adenomas (TSAs) using big data analytics. METHODS: Using a case-control design, we evaluated the risk factors associated with the presence of SSAs and TSAs. Subjects who underwent colonoscopies from 2002 to 2012 as part of the comprehensive health screening programs undertaken at the Samsung Medical Center, Korea, participated in this study. RESULTS: Of the 48 677 individuals who underwent colonoscopies, 183 (0.4%) had SSAs and 212 (0.4%) had TSAs. The multivariate analysis determined that being aged ≥ 50 years (odds ratio [OR] 1.91, 95% confidential interval [CI] 1.27-2.90, P = 0.002) and a history of colorectal cancer among first-degree relatives (OR 3.14, 95% CI 1.57-6.27, P = 0.001) were significant risk factors associated with the presence of SSAs and that being aged ≥ 50 years (OR 2.61, 95% CI 1.79-3.80, P < 0.001), obesity (OR 1.63, 95% CI 1.12-2.36, P = 0.010), and a higher triglyceride level (OR 1.63, 95% CI 1.12-2.36, P = 0.010) were independent risk factors associated with the presence of TSAs. CONCLUSIONS: We used big data analytics to determine the risk factors associated with the presence of specific polyp subgroups, and individuals who have these risk factors should be carefully scrutinized for the presence of SSAs or TSAs during screening colonoscopies.

Indication for endoscopic treatment based on the risk of lymph node metastasis in patients with Siewert type II/III early gastric cancer.

BACKGROUND: Because of the poor prognosis of proximal gastric cancers, there is debate as to whether the conventional indications for endoscopic resection can be used. METHODS: Among subjects who underwent surgery for esophagogastric junction or gastric cardia cancer, 256 patients with T1 type II/III of the Siewert classification were included in this study. The association of lymph node metastasis (LNM) with each variable was analyzed using logistic regression models. A receiver operating characteristic curve was used to determine the discriminatory ability of the model. Propensity score-matched non-cardia cancer patients were selected to compare LNM and long-term survival rates. RESULTS: Of the 256 patients with T1 Siewert II/III gastric cancer, 21 (8.2%) had LNM. Because there was no LNM in T1a cancers, risk factors were analyzed only in patients with T1b. Tumor size (OR 1.42, 95% CI 1.10-1.82, P = 0.007) and lymphovascular invasion (LVI) (OR 5.13, 95% CI 1.88-14.06, P = 0.002) were determined to be predictors of LNM (sensitivity = 66.7% and specificity = 81.6%). Among patients without LVI, the groups with negligible risk for LNM were mucosa-confined cancer, or SM1 cancer with a tumor size ≤3 cm. No LNM was observed in patients satisfying the absolute or extended criteria for endoscopic resection of early gastric cancers. LNM and long-term survival rates of patients with Siewert II/III did not differ significantly compared with matched non-cardia cancer patients. CONCLUSIONS: Tumor size and LVI were associated with LNM in patients with early Siewert type II/III gastric cancer, and the expanded indication for endoscopic resection may be used.

Comparison of Long-Term Outcomes After Non-curative Endoscopic Resection in Older Patients with Early Gastric Cancer.

BACKGROUND: Limited data exist that describe the long-term outcomes from additional surgery following non-curative endoscopic resection (ER) of early gastric cancer (EGC) in older people. This study aimed to determine the appropriate treatment strategy for these patients. METHODS: We analyzed data from 2895 patients who underwent ER for EGC, of whom 451 (15.6%) had non-curative resections followed by curative surgery or surveillance only. Of these patients, 138 were older (aged ≥70 years). We compared the long-term outcomes of the different treatment strategies in the older patients with non-curative resections for EGC, and the outcomes of each treatment strategy, with those in younger patients. RESULTS: The older patients underwent curative resections, non-curative resections with surgery, or non-curative resections with surveillance, and the 5-year disease-specific survival (DSS) rates were 100, 100, and 73%, respectively. There was a trend toward significance for DSS in favor of the non-curative resections with surgery group compared with the non-curative resections with surveillance-only group (p = 0.069). Among those who did not undergo additional surgery, the older patients had worse DSS than the younger patients, and patients who underwent additional surgery had better DSS, irrespective of their ages. Multivariable analysis adjusted for other-cause mortality generated similar results. Overall survival and recurrence-free survival did not differ according to treatment strategy, and perioperative morbidity and mortality did not differ significantly according to age. CONCLUSIONS: In older patients with non-curatively resected EGC, additional surgery demonstrated a trend toward better DSS, and perioperative complications did not increase significantly.

Measurement of tumor volume is not superior to diameter for prediction of lymph node metastasis in early gastric cancer with minute submucosal invasion.

BACKGROUND/AIM: The current indication for endoscopic resection in early gastric cancer (EGC) with minute (< 500 µm) submucosal invasion is based on tumor diameter, which may be insufficient to predict lymph node metastasis (LNM). We investigated whether tumor volume might more accurately predict LNM in EGC with minute submucosal invasion. MATERIALS AND METHODS: Among patients who underwent gastrectomy for gastric cancer, 346 with well/moderately differentiated EGC with submucosal invasion <500 µm were evaluated. Three-dimensional tumor volume was calculated using an endoscopically resected specimen and compared with 1-dimensional tumor diameter. Predictive ability of tumor diameter or volume for LNM was evaluated using receiver operating characteristic curve analysis. RESULTS: Tumor diameter and volume predicted LNM with an area under the curve (AUC) of 0.567 and 0.589, respectively. AUC, sensitivity, specificity, positive and negative predictive values, and accuracy of the 2 models were not significantly different. Tumor diameter ≥ 3 cm showed a significant association with LNM (odds ratio [OR], 2.57; 95% confidence interval [CI], 1.01-6.57; P = 0.049), whereas a tumor volume cutoff value of 752.8 cm3 showed no significant association with LNM (OR, 1.52; 95% CI, 0.59-3.88; P = 0.385). CONCLUSIONS: Tumor volume had no advantage over diameter for predicting LNM in well/moderately differentiated EGC with minute submucosal invasion.

Early gastric cancer with a mixed-type Lauren classification is more aggressive and exhibits greater lymph node metastasis.

BACKGROUND: The clinicopathological features of mixed-type (MT) early gastric cancer (EGC) according to Lauren's classification remain uninvestigated. This study aimed to clarify the clinicopathological features of MT EGC, particularly in relation to lymph node metastasis (LNM) and long-term survival. METHODS: This study included 5309 patients who underwent gastrectomy for EGC. The clinicopathological features, LNM, and long-term outcomes of patients with MT carcinomas were compared with those of patients with intestinal-type (IT) and diffuse-type (DT) cancers. Furthermore, we evaluated the predictors of LNM in each Lauren classification subgroup. RESULTS: Patients with MT carcinomas were likelier to have larger tumors, submucosal invasion, lymphovascular invasion, and LNM than those with IT or DT carcinomas. Multivariate logistic regression analysis revealed that the Lauren classification was a significant predictor of LNM (P < 0.001). The significant predictors of LNM in MT carcinomas were female sex, greater tumor size, presence of submucosal invasion, and lymphovascular invasion. However, the overall survival of patients with MT carcinoma was not significantly different from that of patients with IT or DT carcinomas (P = 0.104). CONCLUSIONS: The presence of MT EGC carries a higher risk of LNM compared with the presence of IT or DT carcinomas. Therefore, MT carcinomas should be managed with gastrectomy that includes lymph node dissection instead of endoscopic resection.

A Risk-prediction Model Based on Lymph-node Metastasis for Incorporation Into a Treatment Algorithm for Signet Ring Cell-type Intramucosal Gastric Cancer.

OBJECTIVE: The aim of the study was to develop a reliable and easy-to-use risk-scoring system (RSS) to predict lymph-node metastasis (LNM) and determine the feasibility of endoscopic submucosal dissection for mucosa-confined signet ring cell carcinomas (SRCs). BACKGROUND: Fewer LNM and better survival rates have been reported for early gastric SRCs compared with other undifferentiated early gastric cancers (EGCs). METHODS: Data from 1544 patients with mucosa-confined SRCs were reviewed. Stepwise logistic regression analysis determined the independent predictors of LNM. Risk scores were based on the final predictive factors for LNM, and performance was internally validated using a split-sample approach. External validation was also performed in an independent dataset (n = 208) to assess the discriminatory power of the RSS. RESULTS: The overall LNM incidence was 3.8% (57/1544). Three risk factors (tumor size ≥1.7 cm, tumors of elevated type, and lymphatic-vascular involvement) were significantly associated with LNM. These factors were incorporated into the RSS, and were assigned scores ranging from 0 to 4. The area under the receiver-operating characteristic curve for predicting LNM after internal and external validation was 0.68 (95% confidence interval, 0.0793-0.2865) and 0.686 (95% confidence interval, 0.618-0.748), respectively. A score of 2 points was the optimal cut-off value for LNM prediction, and the overall diagnostic accuracy was 96%. LNM were found in 2.9% and 23.8% of the low and high-risk groups of the RSS, respectively. CONCLUSIONS: A RSS may help to predict LNM and evaluate endoscopic submucosal dissection feasibility in patients with intramucosal SRC.

Clinicopathological Features and Prognosis of Mixed-Type T1a Gastric Cancer Based on Lauren's Classification.

BACKGROUND: Recent studies have reported that mixed-type (MT) gastric cancer, as per Lauren's classification, exhibits aggressive behavior. However, the behavior of early gastric cancer is unclear. In this study, we addressed the influence of mucosa-confined MT gastric cancer, according to Lauren's classification, on lymph node metastasis (LNM) and long-term outcomes. METHODS: Among patients who underwent gastrectomy for gastric cancer from January 2000 to December 2012, 3170 had mucosa-confined gastric cancer. According to Lauren's classification, 1449 (45.7 %), 1528 (48.2 %), and 193 (6.1 %) patients had intestinal type (IT), diffuse type (DT), and MT cancer, respectively. Moreover, patients with MT cancer were histologically subdivided into IT-predominant MT (3.0 %) and DT-predominant MT (2.5 %) groups. We analyzed and compared the clinicopathological characteristics, incidence of LNM, overall survival, and recurrence-free survival between these groups. RESULTS: Clinicopathological characteristics showed that mucosa-confined MT gastric cancer had larger size, deeper invasion, and more frequent lymphovascular invasion compared with IT or DT cancers. The LNM of MT lesions (4.7 %) was comparable with that of DT lesions (4.8 %), and multivariate logistic regression analysis indicated that Lauren's classification was a significant predictor for LNM (P < 0.001). However, the overall survival and recurrence-free survival of patients with MT lesions did not differ significantly (P = 0.506 and 0.359, respectively). CONCLUSIONS: Thus, among patients with mucosa-confined gastric cancer, those with MT cancer as per Lauren's classification have aggressive clinical features and a risk of LNM. Hence, surgical treatment may be the preferred option in these patients.