Prediction of Overall Survival and Novel Classification of Patients with Gastric Cancer Using the Survival Recurrent Network

BACKGROUND

Artificial neural networks (ANNs) have been applied to many prediction and classification problems, and could also be used to develop a prediction model of survival outcomes for cancer patients.

OBJECTIVE

The aim of this study is to develop a prediction model of survival outcomes for patients with gastric cancer using an ANN.

METHODS

This study enrolled 1243 patients with stage IIA-IV gastric cancer who underwent D2 gastrectomy from January 2007 to June 2010. We used a recurrent neural network (RNN) to make the survival recurrent network (SRN), and patients were randomly sorted into a training set (80%) and a test set (20%). Fivefold cross-validation was performed with the training set, and the optimized model was evaluated with the test set. Receiver operating characteristic (ROC) curves and area under the curves (AUCs) were evaluated, and we compared the survival curves of the American Joint Committee on Cancer (AJCC) 8th stage groups with those of the groups classified by the SRN-predicted survival probability.

RESULTS

The test data showed that the ROC AUC of the SRN was 0.81 at the fifth year. The SRN-predicted survival corresponded closely with the actual survival in the calibration curve, and the survival outcome could be more discriminately classified by using the SRN than by using the AJCC staging system.

CONCLUSION

SRN was a more powerful tool for predicting the survival rates of gastric cancer patients than conventional TNM staging, and may also provide a more flexible and expandable method when compared with fixed prediction models such as nomograms.

[Ethical, pedagogical, socio-political and anthropological implications of quaternary prevention]

The concept of quaternary prevention, resulting from a reflection on the doctor-patient relationship, is presented as a renewal of the ageold ethical requirement: first, a doctor must not harm; second, the doctor must control himself/herself. The origin of the concept, its endorsement by the World Organization of Family Doctors (WONCA) and the European Union of General Practitioners (UEMO), its dissemination, and the debates to which it has given rise, are presented by a panel of authors from 12 countries and 3 continents. This collective text deals more specifically with the ethics of prevention, the importance of teaching Quaternary prevention and Evidence Based Medicine, the social and political implications of the concept of quaternary prevention, and its anthropological dimensions.

Protective Effects of Female Reproductive Factors on Lauren Intestinal-Type Gastric Adenocarcinoma

PURPOSE

Gastric cancer shows a male predominance that might be explained by protective effects from estrogens in females. Two Lauren classification histological subtypes, intestinal and diffuse, have distinct carcinogeneses. The purpose of this study was to estimate the effects of sex hormone on female gastric cancer according to Lauren classification.

MATERIALS AND METHODS

We reviewed medical records for and administered questionnaires, surveying reproductive and hormonal factors, to 758 patients who underwent gastrectomy for gastric cancer at Samsung Medical Center from May 2012 to November 2014. Clinicopathological characteristics were compared between females and males. The incidence of intestinal-type gastric cancer was compared between females subgroups, consist of premenopausal women and three groups of postmenopausal women (five-year intervals after menopause), and males. The association between reproductive factors and intestinal-type gastric cancer was analyzed by multivariate models for the female group.

RESULTS

In total, 227 females (29.9%) and 531 males (70.9%) were included in the analysis. Undifferentiated adenocarcinoma and diffuse-type histology were more frequent in female patients than male patients. While 221 (41.6%) male patients had intestinal-type gastric cancer, no premenopausal female patient had this type of gastric cancer. The incidence of intestinal-type gastric cancer increased with time after menopause, and was similar to males after 10 years from menopause. Parity was associated with an increased risk of intestinal-type gastric cancer in menopausal women.

CONCLUSION

These findings support that female sex hormones might be protective against intestinal-type gastric cancer.

Programmed cell death-ligand 1 expression predicts survival in patients with gastric carcinoma with microsatellite instability

Programmed death-ligand 1 (PD-L1) is expressed in a subgroup of gastric cancers that may benefit from immunotherapy. Microsatellite instability-high (MSI-H) is a potential predictive factor for response to immunotherapy targeting the PD-1 or its ligand PD-L1. The relationship between PD-L1 expression and MSI-H status remains poorly understood. In this study, we investigated PD-L1 expression in patients with MSI-H gastric cancer. We analyzed PD-L1 expression in 78 MSI-H gastric cancer tissue samples using immunohistochemistry. PD-L1 expression was classified as expression on tumor cells or on immune cells. We observed PD-L1 expression in 48 gastric cancer samples (61.5%), consisting of 7 (9.0%) cases with tumor PD-L1 expression and 47 (60.3%) cases with immune cell PD-L1 expression. Immune cell PD-L1 expression was frequently associated with intestinal type cancer by the Lauren classification (p = 0.015), with a lower risk of lymph node metastasis (p = 0.027) and lower tumor stages (p = 0.029) compared to MSI-H gastric cancers without PD-L1 expression. Moreover, immune cell PD-L1 expression was an independent favorable prognostic factor for overall survival (versus PD-L1 negative; hazard ratio, 3.451; 95% confidence interval, 1.172–12.745; p = 0.025). In MSI-H gastric cancer, PD-L1 expression was observed to be independently associated with a longer survival.

Host immune response index in gastric cancer identified by comprehensive analyses of tumor immunity

Tumor infiltrating lymphocytes (TIL) in Epstein-Barr virus (EBV)-associated/microsatellite-unstable (MSI) gastric carcinomas (GC) constitute immune-active principal cellular components of tumor microenvironment and contribute to better prognosis. With the remarkable success of cancer immunotherapies, there is an urgent need for a comprehensive understanding of tumor-immune interactions in patients with GC in the context of host immune response. To identify GC subtype-specific immune response gene set, we tested differentially expressed genes for MSI and EBV+ GC subtypes in randomly selected test set (n = 278) in merged ACRG-SMC microarray and TCGA RNA sequencing data set. We identified Host ImmunE Response index (HIERÏ) consisting of 29 immune genes classifying GC patients into robust 3 groups with prognostic significance. Immune-high cluster 1 was enriched with PD-L1^High/EBV+/MSI/TIL^High with the best clinical outcome while immune-low cluster 3 displayed worst outcome and exemplified with PD-L1^Low/EBV-/MSS. The results were validated in the same cohort (n = 279) and independent cohort (n = 181) with RNA from formalin-fixed paraffin-embedded (FFPE) tissue. Unexpectedly, nearly half of GC in cluster 1 were EBV-/MSS and 10% of cluster 3 GC were EBV+/MSI GC patients, suggesting that in addition to EBV+/MSI GC subtypes, EBV-/MSS subtype also constitutes almost half of high immune cluster and would be a good candidate for immune checkpoint inhibitor therapy. In contrary, almost 10% of EBV+/MSI GC patients may not respond to immune checkpoint inhibitor therapy. Thus, our HIERÏ gene signature demonstrates the potential to subclassify tumor immunity levels, predict prognosis and help immunotherapeutic decisions.

Direct analysis of aberrant glycosylation on haptoglobin in patients with gastric cancer

Based on our previous studies, differential analysis of N-glycan expression bound on serum haptoglobin reveals the quantitative variation on gastric cancer patients. In this prospective case-control study, we explore the clinically relevant glycan markers for gastric cancer diagnosis. Serum samples were collected from patients with gastric cancer (n = 44) and healthy control (n = 44). N-glycans alteration was monitored by intact analysis of Hp using liquid chromatography–mass spectrometry followed by immunoaffinity purification with the serum samples. Intensity and frequency markers were defined depending on the mass spectrometry data analysis. Multiple markers were found with high diagnostic efficacy. As intensity markers (I-marker), six markers were discovered with the AUC > 0.8. The high efficiency markers exhibited AUC of 0.93 with a specificity of 86% when the sensitivity was set to 95%. We additionally established frequency marker (f-marker) panels based on the tendency of high N-glycan expression. The AUC to conclude patients and control group were 0.82 and 0.79, respectively. This study suggested that N-glycan variation of serum haptoglobin were associated with patients with gastric cancer and might be a promising marker for the cancer screening.

Plexiform Angiomyxoid Myofibroblastic Tumor of the Stomach: a Rare Case

Plexiform angiomyxoid myofibroblastic tumor (PAMT) of the stomach is a very rare mesenchymal tumor of the gastrointestinal tract. We report a case of asymptomatic gastric PAMT that was pathologically confirmed after surgical resection. The tumor had a multinodular plexiform growth pattern, bland-looking spindle cells, and an Alcian blue-positive myxoid stromal matrix rich in small blood vessels. Immunohistochemistry analysis revealed that the tumor cells of the PAMT were positive for smooth muscle actin (SMA) and negative for c-kit, CD34, S-100 protein, epithelial membrane antigen (EMA), and desmin. PAMT should be differentiated from other submucosal tumors of the stomach by immunohistochemical findings. Considering the benign features of this tumor, observation without resection may be an option for the treatment of PAMT if the tumor is asymptomatic.

Multiple Primary Malignancies in Patients with Multiple Early Gastric Cancer

Purpose

This study aimed to investigate the correlation between multiple early gastric cancer (MEGC) and multiple primary malignancies during the follow-up of patients with gastrectomy.

Materials and Methods

The number of primary tumors detected in other organs after gastrectomy for early gastric cancer (EGC) has been increasing because of improved survival and surveillance programs. A total of 3,129 patients underwent radical gastrectomy for treatment of EGC at Samsung Medical Center from January 2000 to December 2005. Of these, 3,057 patients were selected and their medical records were retrospectively analyzed.

Results

Among the 3,057 patients, 148 (4.8%) had MEGC, 84.5% were male, 57.4% were over 60 years old, 42.6% had a macroscopic type EGC IIb main lesion, and 68.9% had well-differentiated tumors with a significantly high incidence of MEGC. There were no differences between patients with solitary early gastric cancer (SEGC) and those with MEGC with regard to overall survival or recurrence-free survival, but MEGC was an independent risk factor for metachronous primary malignancies in other organs (P=0.004, hazard ratio [HR]=2.444).

Conclusions

MEGC is not a risk factor for poor prognosis after curative gastrectomy, but it is a risk factor for metachronous primary malignancies in other organs during postoperative follow-up; therefore, careful surveillance is needed.

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.

Periorbital melasma: Hierarchical cluster analysis of clinical features in Asian patients

BACKGROUND

Studies have shown melasma lesions to be distributed across the face in centrofacial, malar, and mandibular patterns. Meanwhile, however, melasma lesions of the periorbital area have yet to be thoroughly described.

METHODS

We analyzed normal and ultraviolet light-exposed photographs of patients with melasma. The periorbital melasma lesions were measured according to anatomical reference points and a hierarchical cluster analysis was performed.

RESULTS

The periorbital melasma lesions showed clinical features of fine and homogenous melasma pigmentation, involving both the upper and lower eyelids that extended to other anatomical sites with a darker and coarser appearance. The hierarchical cluster analysis indicated that patients with periorbital melasma can be categorized into two clusters according to the surface anatomy of the face. Significant differences between cluster 1 and cluster 2 were found in lateral distance and inferolateral distance, but not in medial distance and superior distance. Comparing the two clusters, patients in cluster 2 were found to be significantly older and more commonly accompanied by melasma lesions of the temple and medial cheek.

CONCLUSION

Our hierarchical cluster analysis of periorbital melasma lesions demonstrated that Asian patients with periorbital melasma can be categorized into two clusters according to the surface anatomy of the face.

Prognostic implication of hepatoduodenal ligament lymph nodes in gastric cancer

There has been controversy regarding whether hepatoduodenal lymph node (HDLN) metastasis in gastric cancer is distant or regional metastasis. HDLN positivity was classified as distant metastasis in the 7th American Joint Committee on Cancer (AJCC) classification, but it was reclassified as regional lymph node metastasis in the 8th AJCC classification. The aim of our study is to verify prognostic significance of HDLN metastasis in gastric cancer.This retrospective study enrolled patients with gastric cancer who underwent D2 gastrectomy from January 2007 to June 2010. HDLN was classified as a regional lymph node.Total number of patients was 3175; 143 (4.5%) of them had HDLN metastasis. The HDLN positivity was significantly associated with older age, more advanced tumor stage, undifferentiated histologic type, and pathologic diagnosis of lymphatic, vascular, and perineural invasions. Five-year survival rate of HDLN-positive patients with stages I to III disease was significantly higher than that of stage IV group (59.3% vs 18.8%, P = 0.001). In patients with stage III disease, 5-year survival rate of HDLN-positive group was significantly lower than that of HDLN-negative group (51.7% vs 66.3%, P = 0.001). Multivariate analysis showed that HDLN metastasis was an independent prognostic factor.HDLN has a different prognostic significance from other regional lymph nodes in advanced stage of gastric cancer though its positivity is not considered as distant metastasis. HDLN positivity itself seems to be an independent prognostic factor in gastric cancer, and the survival outcomes of patients with stage III disease need to be reconsidered according to HDLN positivity.

Risk Factors and Tumor Recurrence in pT1N0M0 Gastric Cancer after Surgical Treatment

Purpose

This study aimed to evaluate the rate, patterns, and risk factors associated with tumor recurrence in patients with T1N0 gastric cancer.

Materials and Methods

The medical records of 8,753 patients with pathological T1N0M0 gastric cancer who underwent gastrectomy between 1994 and 2014 at Sungkyunkwan University School of Medicine were examined.

Results

Among the 8,753 patients, 95 patients (1.1%) experienced tumor recurrence; this included 31 remnant, 27 hematogenous, 9 lymph nodal, 5 peritoneal, and 23 multiple-site recurrences. When patients were divided into two groups according to the presence of tumor recurrence, the following characteristics were higher in the recurrence group than in the non-recurrence group: older age (≥65 years), male gender, undifferentiated histology, submucosal invasion, and venous invasion. In multivariate analysis, older age, male gender, tumor depth (sm2 and sm3 invasion), and venous invasion were independent risk factors for tumor recurrence. The recurrence rates were 0.7% in patients with less than two risk factors, 1.7% in those with two risk factors, 3.0% in those with three risk factors, and 6.3% in those with four risk factors (P<0.001).

Conclusions

Although tumor recurrence is rare in pT1N0M0 gastric cancer, some patients with certain risk factors demonstrate an increased rate of tumor recurrence. Careful follow-up is required for patients with three or four risk factors.

The prognostic effects of tumor infiltrating regulatory T cells and myeloid derived suppressor cells assessed by multicolor flow cytometry in gastric cancer patients

The prognostic effects of tumor infiltrating lymphocytes (TILs), especially regulatory T cells (Tregs) and myeloid derived suppressing cells (MDSCs) are inconclusive in gastric cancers. We investigated the frequencies of TILs including CD8+ T cells, CD45+CD4+CD25± FOXP3+ Tregs, CD45+CD11b+ CD14+ HLA−DR− MDSCs in 28 gastric cancer tissues by using multicolor flow cytometry. In gastric cancer tissue, the percentage of Tregs among the CD4+ T cell subset was substantially increased compared to that of Tregs among peripheral blood CD4+ T cells from the controls. High frequency of CD8+ T cells among CD3+ T cells correlated with increased overall survival (OS) (p = 0.005). High frequency of Tregs among CD4+ T cells correlated with increased OS (p < 0.001), and disease-free survival (DFS) (p = 0.039) and was an independent prognostic factor in OS (Hazard ratio: 0.047; 95% confidence interval, 0.006-0.372; p = 0.004). High frequency of MDSCs among total examined cells correlated with decreased OS (p = 0.027) and was an independent prognostic factor in OS (Hazard ratio 8.601; 95% confidence interval, 1.240-59.678; p = 0.029). We have demonstrated that high levels of Tregs among tumor-infiltrating CD4+ T cells were favorable, but an increased proportion of MDSCs was an adverse independent prognostic factor in gastric cancer. Our results may provide important insights for future immunotherapy in gastric cancer.

Does the interval of screening endoscopy affect survival in gastric cancer patients?: A cross-sectional study

Gastric cancer remains the second most common cancer in Korea; however, its mortality has decreased due to earlier diagnosis. In Korea, screening endoscopy has been performed nationwide since 1999. The aim of this study was to elucidate the benefit of screening endoscopy on actual survival in gastric cancer patients and to determine the optimal interval of screening endoscopy.We analyzed 1651 patients diagnosed with gastric adenocarcinoma who underwent surgical treatment between June 2008 and December 2014. Patients were divided into 4 groups according to the interval of screening endoscopy prior to their gastric cancer diagnosis. (Group I = within 1 year, Group II = >1 but <2 years, Group III = more than 2 years, Group IV = no prior endoscopic examination). Patient demographics, clinicopathologic characteristics, and postoperative surgical outcomes including overall survival were compared.The 5-year gastric cancer-specific survival rates of groups I and II were significantly higher than groups III and IV (90.9% vs 85.4%, P = 0.002, respectively). Multivariate analysis showed that screening interval was an independent factor for the diagnosis of advanced gastric cancer. The risk of advanced gastric cancer decreased in group I (odds ratio: 0.515, 95% confidence interval [CI] 0.369-0.719; P < 0.001) and group II (odds ratio: 0.678, 95% CI 0.517-0.889, P = 0.005).Screening endoscopy was helpful in increasing the survival of gastric cancer patients. A 2-year endoscopic screening interval is suitable to detect early-stage gastric cancer.

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.

Ideal number of biopsy tumor fragments for predicting HER2 status in gastric carcinoma resection specimens

Intratumoral heterogeneity of HER2 expression is common in gastric cancers and pose a challenge for identifying patients who would benefit from anti-HER2 therapy. The aim of this study is to compare HER2 expression in biopsy and resection specimens of gastric carcinoma by immunohistochemistry (IHC) and to find the ideal number of biopsy tumor fragments that can accurately predict HER2 overexpression in the corresponding surgically resected specimen. The HER2 IHC results of 702 paired biopsy and resection specimens of gastric cancer were compared.The mean number of biopsy fragments among all cases was 4.3 (range 1-11). HER2 was positive in 130 (18.5%) endoscopic biopsies and in 102 (14.5%) gastrectomy specimens. Intratumoral heterogeneity of HER2 was found in 80 (61.5%) biopsies and 70 (68.6%) resection specimens. Out of the 70 surgical specimens with intratumoral heterogeneity, 24 (34.3%) of the corresponding biopsies were categorized as negative (positive conversion). In the 86 (12.3%) discrepant cases, negative conversion was observed in 57 (66.3%) cases and positive conversion in 29 (33.7%). The fragment numbers were significantly correlated with the discrepancy of results and positive predictability (P = 0.0315 and P = 0.0052). ROC curve analysis and positive predictability showed that 4 fragments should be obtained to minimize the differences in HER2 scores between biopsy and resection specimen.In gastric carcinomas with discrepant HER2 results between biopsy and surgical resection specimens, intratumoral heterogeneity is common with most of them showing positive conversion. To predict HER2 status precisely, at least 4 biopsy fragments containing tumor cells are required.

FGFR2 in gastric cancer: protein overexpression predicts gene amplification and high H-index predicts poor survival

FGFR2 gene amplification, and resulting FGFR2 protein overexpression, is rare in gastric cancer patients, and development of an accurate and widely available method for mass screening to identify patients who may respond to treatment with fibroblast growth factor receptor (FGFR) inhibitors is important. We first screened 312 gastric cancer patients with known copy number variations by FGFR2b immunohistochemistry using FPR2-D, an isoform-specific antibody. Next, we performed immunohistochemistry on tissue microarrays from 1574 gastric cancer patients. Selected cases were analyzed for FGFR2 amplification by FISH. In addition, FGFR2b overexpression was studied in 88 matched primary and metastatic gastric cancers. In the first cohort, FGFR2b immunohistochemistry results correlated very well with those of copy number variation (r=0.79) and FISH (r=1.0). In total, FGFR2b overexpression was identified in 73 of 1974 gastric cancers (4%). The concordance between immunohistochemistry and FISH was extremely high; all 2+ and 3+ cases identified by immunohistochemistry were FGFR2 amplified. In the matched primary and metastatic gastric cancer pairs, the positivity and percentage of positive tumor cells were significantly higher in metastatic gastric cancers than in primary gastric cancers (8% vs 3% and 75% vs 47%, respectively; P<0.001). FGFR2b overexpression was significantly more frequent in gastric cancers with diffuse subtype (P=0.01) and higher N stage (P=0.006). FGFR2b overexpression with H-score ≥150 were independent prognostic factors for overall survival with hazard ratio of 1.836 (95% confidence interval, 1.034-3.261; P=0.038). FGFR2b positivity in immunohistochemistry was strongly correlated with FGFR2 amplification. Given the low frequency of FGFR2 amplification in gastric cancers, FGFRb2 immunohistochemistry is an accurate screening tool to detect FGFR2 amplification, and both primary and metastatic gastric cancer tissues should be tested to select gastric cancer patients for treatment with FGFR2 inhibitors.

The Influence of Metastatic Lymph Node Ratio on the Treatment Outcomes in the Adjuvant Chemoradiotherapy in Stomach Tumors (ARTIST) Trial: A Phase III Trial

Purpose

In the Adjuvant Chemoradiotherapy in Stomach Tumors (ARTIST) trial, we investigated whether chemoradiotherapy after D2 gastrectomy reduces the rate of recurrence. Recently, the ratio of metastatic lymph nodes to examined lymph nodes (N ratio) has been proposed as an independent prognostic factor in gastric cancer (GC). The aim of this study was to investigate the relationship between the metastatic N ratio and prognosis of GC after curative D2 surgery.

Materials and Methods

We retrospectively reviewed the data of 458 ARTIST patients who underwent D2 gastrectomy followed by adjuvant chemotherapy (XP, n=228) or chemoradiotherapy (XPRT, n=230). The disease-free survival (DFS) rates of patients were used to evaluate the influence of N ratio on the treatment outcome. To achieve this, 4 different N ratio categories (0%, 1%~9%, 10%~25%, and >25%) were compared on the basis of their influence on the treatment outcome.

Results

On multivariate analysis, the N ratio remained an independent prognostic factor for DFS. The hazard ratios (HRs) for the N ratio categories of 0%, 1%~9%, 10%~25%, and >25% were 1, 1.061, 1.202, and 3.571, respectively. In patients having N ratio >25%, the 5-year DFS rates were 55% and 28% for the XPRT and XP arms, respectively (HR, 0.527; 95% confidence interval, 0.307~0.904; P=0.020).

Conclusions

In patients with curatively resected GC, the N ratio was independently associated with DFS. Although this finding warrants further investigation in future prospective studies, the benefit of chemoradiotherapy for D2 resected GC appears to be more beneficial in cancers having N ratios >25%.

Should an Aberrant Left Hepatic Artery Arising from the Left Gastric Artery Be Preserved during Laparoscopic Gastrectomy for Early Gastric Cancer Treatment?

Purpose

During laparoscopic gastrectomy, an aberrant left hepatic artery (ALHA) arising from the left gastric artery (LGA) is occasionally encountered. The aim of this study was to define when an ALHA should be preserved during laparoscopic gastrectomy.

Materials and Methods

From August 2009 to December 2014, 1,340 patients with early gastric cancer underwent laparoscopic distal gastrectomy. One hundred fifty patients presented with an ALHA; of the ALHA was ligated in 116 patients and preserved in 34 patients. Patient characteristics, postoperative outcomes and perioperative liver function tests were reviewed retrospectively. Correlations between the diameter of the LGA measured on preoperative abdominal computed tomography and postoperative liver enzyme levels were analyzed.

Results

Pearson's correlation analysis showed a positive correlation between the diameter of the LGA and serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels on postoperative day 1 in the ALHA-ligated group (P=0.039, P=0.026, respectively). Linear regression analysis estimated the diameter of the LGA to be 5.1 mm and 4.9 mm when AST and ALT levels were twice the normal limit on postoperative day 1.

Conclusions

We suggest preserving the ALHA arising from a large LGA, having diameter greater than 5 mm, during laparoscopic gastrectomy to prevent immediate postoperative hepatic dysfunction.

The risk of lymph node metastases in 3951 surgically resected mucosal gastric cancers: implications for endoscopic resection

BACKGROUND AND AIMS

Endoscopic resection for mucosal gastric cancer (MGC) is highly recommended in the absence of lymph node metastasis (LNM). We aimed to clarify the risk factors for LNM in MGC and to investigate the association of LNM with the indication criteria for endoscopic submucosal dissection (ESD).

METHODS

A retrospective cohort study was performed on 3951 patients with MGC who underwent radical gastrectomy at the Samsung Medical Center in Seoul, Republic of Korea, between September 1994 and September 2010.

RESULTS

Of the patients with MGC, 101 (2.60%) were positive for LNM. Multivariate analysis, followed by univariate analysis, revealed the following risk factors for LNM in MGC: large tumor size, undifferentiated tumor type, lymphatic invasion, perineural invasion, and associated ulceration in the tumor (hazard ratio 1.25, 7.49, 20.65, 23.45, and 4.07, respectively). Patients without LNM had significantly increased survival and/or recurrence-free survival rates than patients with LNM (188.4/209.8 months vs 169.5/188.0 months; P = .029/.004, respectively). Only 3 of 1065 patients (0.3%) who met the absolute indication criteria for ESD had LNM. Of those who met the expanded indication criteria for ESD, 11 of 2678 patients (0.4%) had LNM. LNM also was found in 2 patients who had a differentiated tumor <0.5 cm without ulceration.

CONCLUSION

The risk for LNM was very low when patients with MGC met the absolute and/or expanded criteria for endoscopic resection, which meant the indication criteria for ESD was safe and acceptable. However, although the risk for LNM is very low, it should not be considered negligible in endoscopic resection.

Comparison of single-port and reduced-port totally laparoscopic distal gastrectomy for patients with early gastric cancer

BACKGROUND

Laparoscopy-assisted distal gastrectomy (LADG) is a treatment method for patients with early gastric cancer; however, single- or reduced-port LADG for these patients has been rarely reported.

OBJECTIVE

To compare surgical outcomes of patients with gastric cancer undergoing single-port totally laparoscopic distal gastrectomy (TLDG) to those of patients undergoing reduced-port (three ports) TLDG.

METHODS

This retrospective study included 94 patients with early gastric cancer who underwent single-port or reduced-port TLDG at Samsung Medical Center between May 2014 and December 2014. Surgical outcomes were compared between operation methods.

RESULTS

There are more female patients (54.2 vs. 19.6 %, p = 0.001) and less obese patients (21.1 ± 2.1 vs. 24.6 ± 3.2 kg/m(2), p = 0.001) in the single-port TLDG group. There were no significant differences in blood loss during surgery, the number of dissected lymph nodes, and the pain score at postoperative first day between two groups. The variance in operation time for the reduced-port TLDG was significantly greater than that for single-port TLDG (p = 0.01). Complication rates in the single-port and reduced-TLDG groups were similar (20.8 vs. 21.7 %, p = 1.000). No postoperative deaths occurred in either group.

CONCLUSIONS

Single-port TLDG might be considered as a treatment option for a limited subset, such as females or less obese patients with early gastric cancer.