[Epithelioid Hemangioendothelioma of the Upper Mediastinum:Report of a Case].

A 81-year-old woman was referred to our hospital for neck discomfort. Chest computed tomography (CT) showed a tumor in the upper mediastinum. Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed the mild accumulation in the tumor. Percutaneous biopsy was performed and epithelioid hemangioendothelioma was suspected, and the surgical treatment was performed. The histological study showed polygonal and irregular cells with nuclear atypia in myxoma-like substrate compatible with epithelioid hemangioendothelioma.

[Primary Pericardial Malignant Mesothelioma:Report of a Case].

A 67-year-old woman was referred to our hospital for cough and fever. Chest computed tomography (CT) showed some masses showing slightly enhanced effect in the pericardium. FDG-PET showed the accumulation of FDG in the masses. Thoracoscopic surgical biopsy was performed to establish the diagnosis. The histological study showed proliferation of short spindle-shaped cells surrounded by lymphocyte, and the spindle cells were immunohistochemically positive for cytokeratin AE1/AE3, WT-1, D2-40, CAM5.2, intelectin-1 and negative for CEA, TTF-1, napsin A, claudin-4, calretinin, MUC4, PAX8, CD30. These findings were compatible with epithelial pericardial malignant mesothelioma.

SIRT1 Expression Is a Promising Prognostic Biomarker in Esophageal Squamous Cell Carcinoma: A Systematic Review and Meta-analysis.

Background/Aim: Several articles have assessed the prognostic significance of the expression of sirtuin 1 (SIRT1) in esophageal squamous cell carcinoma (ESCC). However, evidence in this field is insufficient. Thus, we conducted a meta-analysis to investigate the prognostic and clinical impact of SIRT1 expression in ESCC. Materials and Methods: We searched the PubMed, Cochrane Library, and Web of Science databases for articles on the expression of SIRT1 and clinicopathological features in patients with ESCC. A meta-analysis was conducted. Results: Four studies with 429 patients were included. The meta-analysis revealed a significant relationship between the high expression of SIRT1 and higher T-stage (odds ratio=2.39. 95% confidence interval=1.12-5.13, p=0.02), more advanced TNM stage (odds ratio=2.35. 95% confidence interval=1.20-4.60, p=0.01), and a poor overall survival (hazard ratio=1.90, 95% confidence interval=1.45-2.47, p<0.00001). Conclusion: SIRT1 expression may be a promising prognostic biomarker for patients with ESCC.

HIF-1α stimulates the progression of oesophageal squamous cell carcinoma by activating the Wnt/ß-catenin signalling pathway.

BACKGROUND: This study aimed to clarify the significance of the crosstalk between hypoxia-inducible factor-1α (HIF-1α) and the Wnt/ß-catenin pathway in oesophageal squamous cell carcinoma (ESCC). METHODS: The oncogenic role of HIF-1α in ESCC was investigated using in vitro and in vivo assays. The clinicopathological significance of HIF-1α, ß-catenin and TCF4/TCF7L2 in ESCC were evaluated using quantitative real-time PCR and immunohistochemistry. RESULTS: The expression level of HIF-1α, ß-catenin, and TCF4/TCF7L2 in T.Tn and TE1 cell lines were elevated under hypoxia in vitro. HIF-1α knockdown suppressed proliferation, migration/invasion and epithelial-mesenchymal transition (EMT) progression, induced G0/G1 cell cycle arrest, promoted apoptosis and inhibited 5-fluorouracil chemoresistance in vitro. In vivo assays showed that HIF-1α is essential in maintaining tumour growth, angiogenesis, and 5-fluorouracil chemoresistance. Mechanically, we identified the complex between HIF-1α and ß-catenin, HIF-1α can directly bind to the promoter region of TCF4/TCF7L2. The mRNA level of HIF-1α, ß-catenin and TCF4/TCF7L2 were increased in ESCC tumour tissues compared to the corresponding non-tumour tissues. High levels of HIF-1α and TCF4/TCF7L2 expression were correlated with aggressive phenotypes and poor prognosis in ESCC patients. CONCLUSIONS: HIF-1α serves as an oncogenic transcriptional factor in ESCC, probably by directly targeting TCF4/TCF7L2 and activating the Wnt/ß-catenin pathway.

Metformin-Induced Heat Shock Protein Family A Member 6 Is a Promising Biomarker of Esophageal Squamous Cell Carcinoma.

INTRODUCTION: Antidiabetic drug metformin exerts various antitumor effects on different cancers. Esophageal squamous cell carcinoma (ESCC) is an intractable digestive organ cancer and new treatment strategy is required. In this study, we performed a comprehensive gene expression analysis of ESCC cell lines treated with metformin, which provided helpful information on the antitumor effects of metformin in ESCC. Next, we selected a promising gene among them and examined its effects on ESCC properties. METHODS: We examined metformin-induced mRNA expression changes in two human ESCC cell lines by performing next-generation sequencing (NGS) and pathway analysis. Heat shock protein family A (Hsp70) member 6 (HSPA6) expression in surgical specimens obtained from 83 ESCC patients who underwent curative operations was evaluated immunohistochemically and analyzed. RESULTS: Metformin upregulated mRNA expression of the many genes, including HSPA6, a cancer immune-related gene, and inhibited mRNA expression of the other many genes. Pathway analysis indicated major canonical pathways and upstream regulators related to metformin. The result indicated HSPA6 as a promising biomarker. HSPA6 expression correlated with disease-free survival (DFS) of the patients with all stage ESCC (p = 0.021), especially with stage I/II ESCC (p < 0.001). With stage III, low HSPA6 expression was not associated with poor DFS (p = 0.918). Multivariate analysis indicated that independent low HSPA6 expression was an independent poor prognostic factor of stage I/II ESCC (p < 0.001). However, HSPA6 expression did not correlate with the clinicopathological characteristics, including age, sex, tumor depth, lymph node metastasis, tumor stage, and tumor markers of the patients with stage I/II ESCC. CONCLUSIONS: This NGS analysis detected prospective candidate genes, including HSPA6. Our results indicate that HSPA6 is a promising biomarker of the recurrence risk of stage I/II ESCC. Further studies on HSPA6 would lead to better treatment.

Biased expression of mutant alleles in cancer-related genes in esophageal squamous cell carcinoma.

BACKGROUND: Recent progress of large-scale international studies has provided comprehensive catalogs of somatic mutations in cancers. Additionally, it has become evident that allelic imbalance in the abundance of somatic mutations between DNA and RNA were pervasive in various types of cancer. However, the allelic imbalance of the abundance of somatic mutations in esophageal squamous cell carcinoma (ESCC) has not been fully analyzed. METHODS: We performed exome sequencing for 25 Japanese patients with ESCC to detect a comprehensive catalog of somatic mutations in ESCC. Additionally, we performed mRNA sequencing to evaluate the allelic imbalance of the identified somatic mutations at the transcriptional level by comparing the mutant allele frequencies between RNA and DNA. RESULTS: The exome sequencing showed that TP53 and ZNF750 were significantly mutated genes. The expression levels of TP53 and ZNF750 were different depending on the mutation status. In almost all the tumors with missense mutations in TP53 and ZNF750, the mutant allele frequencies were higher in the RNA sequencing than those in the exome sequencing, indicating that the mutant alleles were preferentially expressed. By examining the allelic imbalances for all the identified missense mutations, we demonstrated that genes showing preferential expressions of the mutant alleles were involved in the pathways including cell cycle, cell death, and chromatin modification. CONCLUSIONS: The results of this study suggest that the allelic imbalance of the abundance of somatic mutations plays important roles in the initiation and progression of ESCC by modulating cancer-related biological pathways.

[Successful Endoscopic Submucosal Dissection of Early Gastric Cancer after Ulcer Healing Associated with a Malignant Cycle-A Case Report].

A 79-year-old man was detected with anemia on medical examination and underwent gastroscopy at the previous hospital. Gastroscopy revealed a 15-mm ulcerative lesion(Type 0-Ⅱc plus Ⅲ)on the greater curvature of the upper gastric body. Tumor biopsy showed well-differentiated adenocarcinoma. The patient was suspected of deep submucosal invasion due to poor stretching of the gastric wall and the ulcer depth; hence, he was transferred to our hospital for surgery. When gastroscopy was repeated, the ulcer was found to be scarred(Type 0-Ⅱc), thereby indicating the occurrence of intramucosal carcinoma; hence, endoscopic submucosal dissection was performed. The pathological finding showed 10×6 mm, tub1, pT1a, ly0, v0, pUL1, pHM0, pVM0, suggesting a curative resection. Early gastric cancer of the depressed type is known to develop a malignant cycle with repeated improvements and exacerbations of the ulcer. Diagnosing the depth of tumor invasion is particularly difficult when there is an active ulcer. For small lesions with active ulcers, repeating gastroscopy might allow for correct diagnosis and appropriate treatment.

Temperature-Dependent Electron Momentum Spectroscopy on the Molecular Orbitals of Dimethyl Ether.

This paper investigates vibrational excitation effects on valence electron momentum distributions of dimethyl ether. A symmetric noncoplanar (e, 2e) experiment has been performed for the molecule at a high temperature (980 K) as well as at room temperature (300 K). For comparison, theoretical calculations with vibrational effects being involved have also been carried out. Changes of the momentum profiles with the rise of temperature are observed for the 2b1 and 6a1 orbitals, indicating that distortion of these molecular orbitals is appreciably enhanced upon excitation of the methyl torsional vibrations. The present study provides a way for exploring the influence of vibrational excitation on electronic wavefunctions of molecules.

Antitumor Effect of Sugar-Modified Cytosine Nucleosides on Growth of Adult T-Cell Leukemia Cells in Mice.

Adult T-cell leukemia (ATL) is a CD4+ T-cell neoplasm caused by human T-cell leukemia virus type I. As the prognosis for patients with ATL remains extremely poor due to resistance to conventional chemotherapy regimens, introduction of novel therapeutic agents is needed. Previous studies have reported that nucleosides 2'-deoxy-2'-methylidenecytidine (DMDC) and its derivative 2'-deoxy-2'-methylidene-5-fluorocytidine (FDMDC) exhibit antitumor activities in T-cell acute lymphoblastic leukemia (T-ALL) and solid tumor cell lines. Another nucleoside, 1-(2-azido-2-deoxy-ß-D-arabinofuranosyl)cytosine (cytarazid), is considered a therapeutic drug with antitumor activity in human solid tumors. In this study, we investigated the effects of these nucleosides on cell growth in vitro and in vivo using relevant leukemia cell lines and NOD/Shi-scid, IL-2Rgnull (NOG) mice, respectively. The nucleosides demonstrated significant cytotoxic effects in ATL and T-ALL cell lines. Intraperitoneal administration of FDMDC and DMDC into tumor-bearing NOG mice resulted in significant suppression of tumor growth without lethal side effects. Our findings support a therapeutic application of these nucleosides against tumor progression by targeting DNA polymerase-dependent DNA synthesis in patients with ATL.

Tumor-derived exosomes influence the cell cycle and cell migration of human esophageal cancer cell lines.

Our laboratory previously reported the usefulness as biomarkers of exosomes in the plasma of esophageal squamous cell carcinoma (ESCC) patients. However, the influence of tumor-derived exosomes on the tumor itself and underlying mechanisms remain unclear. We here report changes in the phenotype and gene expression when cancer cells exist in an environment with tumor-derived exosomes. The exosomes were isolated from the culture medium of human ESCC cells (TE2, T.Tn) by ultracentrifugation; cell proliferation assay, wound-healing assay, and fluorescence imaging of the cell cycle were performed to clarify the phenotypic changes in the high concentration of tumor-derived exosomes. Gene expression changes were also assessed by mRNA microarray, and the data were analyzed by gene set enrichment analysis (GSEA). The data revealed that the proliferation of both TE2 and T.Tn was inhibited, and cell migration ability was upregulated in the exosome exposure group (P < .05). Fluorescence imaging using a fluorescent ubiquitination-based cell cycle indicator expressing ESCC cells revealed that the ratio of G1-phase cells was significantly increased in the exosome exposure group (P < .05). Findings of the GSEA clarified that high-density exposure of cancer-derived exosomes to their parent cancer cells downregulated the expression of genes related to cell proliferation and cell cycle, and upregulated the expression of genes related to actin filament length and extracellular structure organization. In conclusion, an environment of high-density tumor-derived exosomes induces changes in the gene expression and phenotype of tumor cells and may lead to tumor progression or malignant transformation.

[Solitary Pulmonary Metastasis from Follicular Thyroid Carcinoma Resected 28 Years Earlier Coexisting with Early Lung Cancer;Report of a Case].

A 71-year-old woman was referred to our hospital for a round mass shadow in the right lower lung field in mass screening chest X-ray. Computed tomography (CT) of the chest showed a well-defined lobulating mass shadow measuring 2.2 cm in diameter in the lower lobe of the right lung and a ground glass opacity ( GGO) in the upper lobe of the left lung. She underwent video-assisted partial resection of right lower lobe of the lung. The pathological examinations indicated a pulmonary metastasis of follicular thyroid carcinoma. Three months later, video-assisted partial resection of left upper lobe of the lung was performed. Microscopically, 2 lesions of adenocarcinoma in situ were revealed.

[Development of TP53-Targeted Treatment in Esophageal Squamous Cell Carcinoma Using Cancer Genomic Profiling Test].

Recently, the interest in cancer genomic medicine has increased, owing to the powerful and cost-effective technology of next-generation sequencing(NGS), which allows rapid identification of a large number of gene mutations. TP53 mutations are frequently found in solid cancers, especially in esophageal squamous cell carcinoma(ESCC), wherein the frequency of TP53 mutation is considered to be 90% or more. However, there is no clinical targeted therapy as yet utilizing TP53. Here, we aimed to characterize TP53 mutations associated with ESCC, in order to assess its feasibility as a therapeutic target. We extracted DNA and RNA from specimens of ESCC patients and analyzed them using NGS, which revealed different TP53 mutations. Based on previous reports, it is considered that different TP53 mutations lead to different functions of the protein, and subsequently account for varied prognosis in squamous cell carcinoma of the head and neck. We also performed cell viability assay using ESCC cell lines with different TP53 mutations and 2 kinds of p53-targeted drug and found differences in the growth inhibition of the cell lines. Although individual treatment can be determined depending on the type of TP53 mutation, it would be necessary to further examine the interaction of TP53 with other genes to determine its therapeutic efficacy as a target.

G3BP1 inhibits ubiquitinated protein aggregations induced by p62 and USP10.

The aberrant accumulation of ubiquitinated protein aggregates in cells plays a critical role in the pathogenesis of several degenerative diseases, including Parkinson disease (PD) and cystic fibrosis (CF). In this study, we found that Ras GTPase-activating protein-binding protein 1 (G3BP1) inhibits ubiquitinated protein aggregations induced by p62 and USP10 in cultured cells. p62 is a ubiquitin receptor, and p62 and its binding partner USP10 have been shown to augment ubiquitinated protein aggregation. G3BP1 interacted with p62 and USP10 and inhibited p62/USP10-induced protein aggregation. The G3BP1 inhibition of protein aggregations targeted two aggregation-prone proteins, α-synuclein and CFTR-ΔF508, which are causative factors of PD and CF, respectively. G3BP1 depletion increased the amounts of ubiquitinated α-synuclein and CFTR-ΔF508 protein. A proteasome reporter indicated that G3BP1 depletion inhibits the proteasome activity. We herein present evidence that G3BP1, p62 and USP10 together control ubiquitinated protein toxicity by controlling both ubiquitination and aggregation. Taken together, these results suggest that G3BP1, p62 and USP10 could be therapeutic targets for ubiquitinated protein aggregation disorders, including PD and CF.

Genome-wide ChIP-seq data with a transcriptome analysis reveals the groups of genes regulated by histone demethylase LSD1 inhibition in esophageal squamous cell carcinoma cells.

Expression of genes is controlled by histone modification, histone acetylation and methylation, but abnormalities of these modifications have been observed in carcinogenesis and cancer development. The effect of the lysine-specific histone demethylase 1 (LSD1) inhibitor, a demethylating enzyme of histones, is thought to be caused by controlling the expression of genes. The aim of the present study is to elucidate the efficacies of the LSD1 inhibitor on the gene expression of esophageal cancer cell lines using chromatin immunoprecipitation (ChIP)-Seq. A comprehensive analysis of gene expression changes in esophageal squamous cell carcinoma (ESCC) cell lines induced by the LSD1 inhibitor NCL1 was clarified via analysis using microarray. In addition, ChIP-seq analysis was conducted using a SimpleChIP plus Enzymatic Chromatin IP kit. NCL1 strongly suppressed the proliferation of T.Tn and TE2 cells, which are ESCC cell lines, and further induced apoptosis. According to the combinatory analysis of ChIP-seq and microarray, 17 genes were upregulated, and 16 genes were downregulated in both cell lines. The comprehensive gene expression study performed in the present study is considered to be useful for analyzing the mechanism of the antitumor effect of the LSD1 inhibitor in patients with ESCC.

[Transverse Colectomy with D2 Lymph Node Dissection with a Small Incision Using Body Surface 3D-Simulation CT Colonography].

BACKGROUND: Laparoscopic transverse colectomy is technically difficult. In mini-laparotomy surgery, colectomy for midtransverse colon cancer can easily be performed, but exact D2 lymph node dissection is very difficult for a variety of vessels in the transverse colon. Using 3D-CT imaging, we present a case of D2 lymph node dissection where mini-laparotomy transverse colectomy was performedby a small incision similar to that usedin laparoscopic surgery. METHOD: The patient was a 60-yearoldwoman with early transverse colon cancer, which was locatedin the mid-transverse colon. Surgical treatment was plannedfor pT1b(1.5mm)andpVM1 in pathological findings after EMR. Using CT colonography(CTC), the location of the primary tumor was identified. Using simulation CTC(sCTC), composedof CTC and 3D imaging of the arteries andveins, the dominant artery was identified and D2 lymph node dissection was simulated. In addition, body surface 3D imaging and permeable surface 3D imaging of the abdominal trunk were performed. Using body surface 3D-sCTC, composedof sCTC and body surface 3D imaging, the minimum incision to enable D2 lymph node dissection was simulated. RESULT: Using sCTC, it was identified that the dominant artery was the right branch of the middle colic artery(MCA Rt)andthe accompanying vein was branchedfrom the gastrocolic trunk(GCT). D2 lymph node dissection to separate the branching root of MCA Rt and the accompanying vein was simulated. Next, surgical incision was simulated using body surface 3D-sCTC. Because the branching roots of MCA Rt andGCT were locatedabout 5 cm cranial from the upper rim of the navel, a 7 cm upper abdominal midline incision was designed in addition to a 2 cm umbilical incision. Mini-laparotomy transverse colectomy with a 7 cm incision was performedin accordance with the simulation. The operation time was 2 hours and5 1 minutes, andbloodloss was due to occult bleeding. The patient was discharged 7 days after surgery without complications, and the final diagnosis was pT1bN0M0, StageⅠwith no recurrence for 4 years and2 months after surgery. The cranial incision from the upper rim of the navel has shrank about 3 cm, and the umbilical incision is not noticeable. CONCLUSION: D2 lymph node dissection of minilaparotomy transverse colectomy can be a treatment option for early transverse colon cancer through using body surface 3DsCTC.

[Dawn of Cancer Clinical Sequencing in Chiba University Hospital].

Genome medicine has been attractingmuch of attention in Japan. The combination of molecular targetingdrug s and somatic mutations has been developed for cancer treatment, which was introduced clinically with evidence by cancer type. Several cancer somatic mutations can be identified in a single test inexpensively using next-generation sequencing(NGS). Drug approval not based on organs but on cancer genome analysis has been practiced mainly in the United States, and is also being implemented in Japan. However, cancer treatment strategies using molecular targeting drugs and the associated diagnosis are limited in each type of cancer. Furthermore, the benefit of NGS, which is an improved and inexpensive technique, is still insignificant in Japan. However, the clinical biobank system was initiated in 2011 to prepare the era of cancer genome medicine in our department. The quality of biological samples was strictly controlled by the standardized sampling procedures, which can be used by the researchers accordingto their convenience. Furthermore, the cooperative research involvingcommercial corporations has been started.

[Primary Pulmonary Synovial Sarcoma;Report of a Case].

A 66-year-old man was referred to our hospital for an abnormal shadow. Chest computed tomography (CT)showed a heterogeneous mass with well-defined border in the right S10and ipsilateral pleural effusion. Fluorodeoxyglucose-positron emission tomography(FDG-PET)showed the accumulation in the mass and pleural effusion. Right lower lobectomy with lymphnode dissection was performed for diagnosis and treatment. Histologically,the tumor was mainly composed of complicated spindle-shaped cells with extensive necrosis, showing a large number of nuclear fission images. Immunohistochemistry showed the tumor cells to be positive for cytokeratin AE1/AE3, Bcl-2, EMA, vimentin and negative for TTF-1, S-100, calretinin, CD34, being compatible with monophasic fibrous synovial sarcoma.

The concentration of programmed cell death-ligand 1 in the peripheral blood is a useful biomarker for esophageal squamous cell carcinoma.

BACKGROUND: We determined the serum concentrations of Programmed cell death-1 (PD-1) and its ligands (PD-L1 and PD-L2) in patients with esophageal squamous cell carcinoma (ESCC). METHODS: Blood samples were collected from 85 patients with histologically proved ESCC. Serum levels of PD-1, PD-L1, and PD-L2 were measured using enzyme linked immunosorbent assays. Correlations between serum PD-1, PD-L1, and PD-L2 concentration and tumor depth, number of lymph node metastases, organ metastasis status, or disease stage were assessed and five-year survival rates according to clinicopathological characteristics were calculated. RESULTS: The concentration of PD-1 was not differed according to tumor progression. On the other hand, the average concentration of PD-L1 in patients with T3/T4 disease was 15.6 (12.2-18.3) pg/mL (25-75%), and this was significantly higher than that in patients with Tis/T1/T2 disease (p = 0.020). Similarly, PD-L1 levels were significantly higher in patients with positive lymph nodes than in cases with negative lymph node involvement (p = 0.006) and were higher in patients with organ metastasis (p = 0.123) and in more advanced stage (p = 0.006). Similar tendency was observed regarding PD-L2 concentrations. PD-L2 concentration was higher in T3, T4 cases (p = 0.008), in LN positive cases (p = 0.032), and in more advanced stage (p = 0.024). CONCLUSION: Our data showed that a concentration of PD-L1 in peripheral blood was high in advanced cancer and high concentration of PD-L1 predicted disease progression and also poor survival in patients with ESCC.

Antitumor effects of metformin are a result of inhibiting nuclear factor kappa B nuclear translocation in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is an intractable digestive organ cancer that has proven difficult to treat despite multidisciplinary therapy, and a new treatment strategy is demanded. Metformin is used for type 2 diabetes mellitus and its antitumor effects have been reported recently. Metformin exerts antitumor effects in various respects, such as inhibiting inflammation, tumor growth and epithelial-mesenchymal transition (EMT). However, few reports have described the efficacy of metformin on ESCC, and their findings have been controversial. We analyzed the antitumor effects of metformin and clarified its effects on anti-inflammation, growth suppression and EMT inhibition. Activation of nuclear factor kappa B (NF-κB), the major transcription factor induced by inflammation, was investigated by immunostaining. We found that localization of NF-κB in the nucleus was reduced after metformin treatment. This suggests that metformin inhibited the activation of NF-κB. Metformin inhibited tumor growth and induced apoptosis in ESCC cell lines. Associated with EMT, we examined cell motility by a wound healing assay and the epithelial marker E-cadherin expression of various ESCC cell lines by western blotting. Metformin inhibited cell motility and induced E-cadherin expression. In conclusion, metformin showed multiple antitumor effects such as growth suppression, invasion inhibition, and control of EMT by inhibiting NF-κB localization on ESCC. Further exploration of the marker of treatment efficacy and combination therapy could result in the possibility for novel treatment to use metformin on ESCC.

[Partial Gastrectomy for Elderly Patients with Early-Stage Gastric Cancer].

The aim of this study was to assess the impact of partial gastrectomy on postoperative outcomes in elderly patients with gastric cancer. Sixty -three consecutive elderly patients aged 75 years and older with histologically proven Stage ⅠA gastric adenocarcinoma who underwent partial gastrectomy(PG, n=7)or normal gastrectomy(NG, n=56)were investigated. PG was performed by segmental gastrectomy or local gastrectomy due to poor performance status, severe comorbidities, and social background instead of normal gastrectomy(distal, proximal, and total gastrectomy). Both body mass index(BMI)and body weight changes 12 months postoperatively were significantly higher in those who underwent PG(20.5 kg/m2 vs 18.4 kg/m2, p=0.043; and 96.6% vs 86.4%, p=0.016)despite being statistically similar preoperatively. The 5-year cause-specific survival rate of those who underwent PG was 100% excluding relapse cases. The 5-year overall survival rates were 86% in those who underwent PG and 67%in those who underwent NG, although they differed significantly. Partial gastrectomy may be a valid surgical procedure that may yield better prognosis compared to that with normal gastrectomy for elderly patients with Stage ⅠA gastric cancer.