Prognostic Impact of Post-operative Infectious Complications in Gastric Cancer Patients Receiving Neoadjuvant Chemotherapy: Post Hoc Analysis of a Randomized Controlled Trial, JCOG0501.

PURPOSE: Post-operative infectious complication (IC) is a well-known negative prognostic factor, while showing neoadjuvant chemotherapy (NAC) may cancel out the negative influence of IC. This analysis compared the clinical impacts of IC according to the presence or absence of NAC in gastric cancer patients enrolled in the phase III clinical trial (JCOG0501) which compared upfront surgery (arm A) and NAC followed by surgery (arm B) in type 4 and large type 3 gastric cancer. METHODS: The subjects were 224 patients who underwent R0 resection out of 316 patients enrolled in JCOG0501. The prognoses of the patients with or without ICs in each arm were investigated by univariable and multivariable Cox regression analyses. RESULTS: There were 21 (20.0%) IC occurrences in arm A and 15 (12.6%) in arm B. In arm A, the overall survival (OS) of patients with ICs was slightly worse than those without IC (3-year OS, 57.1% in patients with ICs, 79.8% in those without ICs; adjusted hazard ratio (95% confidence interval), 1.292 (0.655-2.546)). In arm B, patients with ICs showed a trend of better survival than those without ICs (3-year OS, 80.0% in patients with IC, 74.0% in those without IC; adjusted hazard ratio, 0.573 (0.226-1.456)). CONCLUSION: This study could not indicate the negative prognostic influence of ICs in gastric cancer patients receiving NAC, which might be canceled by NAC. To build exact evidence, further investigation with prospective and large numbers of data might be expected.

GSK-3α/ß and MEK inhibitors assist the microenvironment of tumor initiation.

Induced pluripotent stem cells (iPSCs) are useful tools for modeling diseases and developing personalized medicine. We have been developing cancer stem cells (CSCs) from iPSCs with conditioned medium (CM) of cancer-derived cells as the mimicry of the microenvironment of tumor initiation. However, the conversion of human iPSCs has not always been efficient with only CM. In this study, human iPSCs reprogrammed from monocytes of healthy volunteers were cultured in a media containing 50% of the CM from human pancreatic cancer derived BxPC3 cells supplemented with a MEK inhibitor (AZD6244) and a GSK-3α/ß inhibitor (CHIR99021). The survived cells were assessed for the characteristics of CSCs in vitro and in vivo. As a result, they exhibited CSC phenotypes of self-renewal, differentiation, and malignant tumorigenicity. Primary culture of the malignant tumors of the converted cells exhibited the elevated expression of CSC related genes CD44, CD24 and EPCAM maintaining the expression of stemness genes. In conclusion, the inhibition of GSK-3α/ß and MEK and the microenvironment of tumor initiation mimicked by the CM can convert human normal stem cells into CSCs. This study could provide insights into establishing potentially novel personalized cancer models which could help investigate the tumor initiation and screening of personalized therapies on CSCs. Supplementary Information: The online version contains supplementary material available at 10.1007/s10616-023-00575-1.

A Case of Autoimmune Gastritis and Hepatitis with Enlarging Gastric Polyps after Reducing the Dose of Prednisolone.

Autoimmune gastritis is immune-mediated gastritis that destroys the oxyntic mucosa. Autoimmune hepatitis is an inflammatory liver disease caused by an autoimmune reaction. These diseases share similar pathogeneses as organ-specific autoimmune disorders; however, cases involving both diseases are quite rare and scarcely reported. Herein, we report a patient with concurrent autoimmune gastritis and hepatitis who developed enlargement of hyperplastic polyps and progression of gastric atrophy. The patient was a 79-year-old female referred to our hospital for the treatment of hyperplastic polyps detected on a follow-up upper gastrointestinal endoscopy. The patient's previous upper gastrointestinal endoscopy from 3 years prior revealed small hyperplastic polyps and no mucosal atrophy. However, the current upper gastrointestinal endoscopy revealed three 10-mm red polyps, severe mucosal atrophy in the corpus, and mild atrophy in the antral area. In addition, biopsy samples from the gastric body revealed decreased parietal cells and diffuse lymphocytic infiltration of the deep mucosa. Further, chromogranin A-positive endocrine cell micronests and enterochromaffin-like cell hyperplasia were detected. After confirming the diagnosis of autoimmune gastritis, endoscopic mucosal resection was performed for all the polyps, which were histopathologically diagnosed as hyperplastic polyps without malignancy. Therefore, clinicians should consider autoimmune gastritis for enlarged hyperplastic polyps and gastric atrophy progression.

Gastrectomy with or without neoadjuvant S-1 plus cisplatin for type 4 or large type 3 gastric cancer (JCOG0501): an open-label, phase 3, randomized controlled trial.

BACKGROUND: Specific treatment strategies are sorely needed for scirrhous-type gastric cancer still, which has poor prognosis. Based on the promising results of our previous phase II study (JCOG0210), we initiated a phase III study to confirm the efficacy of neoadjuvant chemotherapy (NAC) in type 4 or large type 3 gastric cancer. METHODS: Patients aged 20-75 years without a macroscopic unresectable factor as confirmed via staging laparoscopy were randomly assigned to surgery followed by adjuvant chemotherapy with S-1 (Arm A) or NAC (S-1plus cisplatin) followed by D2 gastrectomy plus adjuvant chemotherapy with S-1 (Arm B). The primary endpoint was overall survival (OS). RESULTS: Between October 2005 and July 2013, 316 patients were enrolled, allocating 158 patients to each arm. In Arm B, in which NAC was completed in 88% of patients. Significant downstaging based on tumor depth, lymph node metastasis, and peritoneal cytology was observed using NAC. Excluding the initial 16 patients randomized before the first revision of the protocol, 149 and 151 patients in arms A and B, respectively, were included in the primary analysis. The 3-year OS rates were 62.4% [95% confidence interval (CI) 54.1-69.6] in Arm A and 60.9% (95% CI 52.7-68.2) in Arm B. The hazard ratio of Arm B against Arm A was 0.916 (95% CI 0.679-1.236). CONCLUSIONS: For type 4 or large type 3 gastric cancer, NAC with S-1 plus cisplatin failed to demonstrate a survival benefit. D2 surgery followed by adjuvant chemotherapy remains the standard treatment.

Association between Household Exposure to Secondhand Smoke and Dental Caries among Japanese Young Adults: A Cross-Sectional Study.

The long-term effects of secondhand smoke (SHS) on dental caries among Japanese young adults remain unclear. The purpose of this cross-sectional study was to evaluate whether household exposure to SHS is associated with dental caries in permanent dentition among Japanese young adults. The study sample included 1905 first-year university students (age range: 18-19 years) who answered a questionnaire and participated in oral examinations. The degree of household exposure to SHS was categorized into four levels according to the SHS duration: no experience (-), past, current SHS < 10 years, and current SHS ≥ 10 years. Dental caries are expressed as the total number of decayed, missing, and filled teeth (DMFT) score. The relationships between SHS and dental caries were determined by logistic regression analysis. DMFT scores (median (25th percentile, 75th percentile)) were significantly higher in the current SHS ≥ 10 years (median: 1.0 (0.0, 3.0)) than in the SHS-(median: 0.0 (0.0, 2.0)); p = 0.001). DMFT ≥ 1 was significantly associated with SHS ≥ 10 years (adjusted odds ratio: 1.50, 95% confidence interval: 1.20-1.87, p < 0.001). Long-term exposure to SHS (≥10 years) was associated with dental caries in permanent dentition among Japanese young adults.

A novel model of liver cancer stem cells developed from induced pluripotent stem cells.

BACKGROUND: Liver cancer is the second most common cause of cancer-related death. Every type of tumours including liver cancer contains cancer stem cells (CSCs). To date, the molecular mechanism regulating the development of liver CSCs remains unknown. METHODS: In this study, we tried to generate a new model of liver CSCs by converting mouse induced pluripotent stem cells (miPSCs) with hepatocellular carcinoma (HCC) cell line Huh7 cells conditioned medium (CM). miPSCs treated with CM were injected into the liver of BALB/c nude mice. The developed tumours were then excised and analysed. RESULTS: The primary cultured cells from the malignant tumour possessed self-renewal capacity, differentiation potential and tumorigenicity in vivo, which were found rich in liver cancer-associated markers as well as CSC markers. CONCLUSIONS: We established a model of liver CSCs converting from miPS and showed different stages of stemness during conversion process. Our CSC model will be important to assess the molecular mechanisms necessary to develop liver CSCs and could help in defeating liver cancer.

Current status of perioperative chemotherapy for locally advanced gastric cancer and JCOG perspectives.

Perioperative treatment for locally advanced gastric cancer has been inconsistent between Japan and the Western countries. In Japan, D2 gastrectomy followed by adjuvant chemotherapy is regarded as standard treatment, while neoadjuvant or perioperative chemotherapy is considered to be a standard in the Western countries. Stomach Cancer Study Group of Japan Clinical Oncology Group (JCOG) has conducted many perioperative chemotherapy trials. After the publishing of positive results of ACTS-GC trial, stage-specific adjuvant chemotherapy protocols are planned. JCOG1104 was conducted as to demonstrate the non-inferiority of four courses of S-1 to standard eight courses of S-1, because the efficacy of S-1 appears to be sufficient in stage II. The trial failed to demonstrate the non-inferiority of four courses of S-1. S-1 for 1 year is still recognized to be a standard for stage II gastric cancer. For stage III, studies with more intensive treatments were planned as the efficacy of S-1 monotherapy seems to be insufficient. As in the Western countries, JCOG planned the perioperative chemotherapy. However, the clinical staging is a serious issue to select optimal patients for perioperative chemotherapy. JCOG conducted a prospective cohort study to evaluate the validity of clinical staging in JCOG1302A. From the results of this study, cT3-4 and cN1-3 are selected as optimal candidate for perioperative chemotherapy. JCOG1509 was conducted to demonstrate the superiority of perioperative chemotherapy to adjuvant chemotherapy in these cohorts. Perioperative chemotherapy for marginally resectable tumours such as linitis plastica or extensive nodal disease and special type of cancer like HER2 positive are also conducted.

Relationship of Salivary Microbiome with the Worsening of the Periodontal Health Status in Young Adults: A 3-Year Cohort Study.

The purpose of this prospective cohort study was to investigate the influence of the salivary microbiome on the worsening of the periodontal health status among Japanese young adults. We assessed the data of systemically healthy and non-smoking young (18-22 years) university students (n = 457) from Okayama University at baseline (2013) and follow-up (2016). The worsening group was defined based on an increase in the percentage of bleeding on probing (%BOP) or an increase in probing pocket depth (PPD) from <4 mm to ≥4 mm. Unstimulated saliva samples were randomly collected from 69 students for microbiome analysis at follow-up. The salivary microbiome was assessed through 16S rRNA metagenomic sequencing. The type of community in the salivary microbiome clustered by statistical analysis and diversity was not significantly associated with the worsening of the periodontal health status in cases of increasing %BOP and PPD (p > 0.05). The prevalence of some species was significantly higher in the worsening group than in the non-worsening group (p < 0.05) in both cases. The worsening of the periodontal health status was associated with some species, but not the type of community and diversity in the salivary microbiome among Japanese young adults.

Associations between sleep bruxism, sleep quality, and exposure to secondhand smoke in Japanese young adults: a cross-sectional study.

OBJECTIVE: Sleep bruxism, a major sleep disorder that causes serious harm to oral health, is considered a multifactorial disease. Sleep bruxism can be induced by smoking, which also adversely affects sleep quality. The objective of present study was to clarify the associations between sleep bruxism, sleep quality, and exposure to secondhand smoke (SHS). METHODS: To assess the prevalence of sleep bruxism, sleep quality, and SHS exposure, we conducted oral examinations and self-report questionnaires on university students in Japan. Sleep bruxism and quality were screened using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI) and the third edition of the International Classification of Sleep Disorders (ICSD-3). The inclusion criteria were adults aged between 18 and 19 years, non-smokers and non-alcohol drinkers. The exclusion criteria was failing to complete the questionnaire in full. RESULTS: We analyzed a total of 1781 Japanese young adults. Young adult females who had been exposed to SHS had worse sleep quality (p = 0.019) than those who had not. Young adult female with worse sleep quality showed a higher prevalence of sleep bruxism (p = 0.034) than those with better sleep quality. Using structural equation modeling, direct associations were identified between SHS exposure and poor sleep quality (standardized coefficients, 0.153; p = 0.008) and between sleep bruxism and poor sleep quality (standardized coefficients, 0.187; p = 0.022) in young adult females. However, no association was found among young adult males. CONCLUSION: SHS exposure is indirectly associated with sleep bruxism through poor sleep quality in Japanese young adult females.

A Phase I/Ib trial of Ad-REIC in liver cancer: study protocol.

This study will assess the safety and efficacy of the administration of adenoviral vector expressing the human-reduced expression in immortalized cells (Ad-REIC) to a liver tumor in patients with hepatocellular carcinoma (HCC) or liver metastasis of pancreatic cancer. A Phase I clinical study of Ad-REIC administration to a liver tumor in a patient with HCC or liver metastasis of pancreatic cancer will be conducted. The study is a single-arm, prospective, nonrandomized, noncomparative, open-label, single-center trial performed in Okayama University Hospital, Okayama, Japan. Ad-REIC will be injected into the liver tumor under ultrasound guidance. Ad-REIC administration will be repeated a total of three-times every 2 weeks. The primary end point is the dose-limiting toxicity and incidence of adverse events. The secondary end points are the objective response rate and disease control rate. This study aims to expand the indication of Ad-REIC by assessing its safety and efficacy in patients with HCC or liver metastasis of pancreatic cancer.

Metastasis of Cancer Stem Cells Developed in the Microenvironment of Hepatocellular Carcinoma.

Metastasis develops when cancer cells spread from the primary site of a malignant tumor to the surrounding and distant tissues, and it is the most critical problem in cancer treatment. Our group developed cancer stem cells (CSCs) from induced pluripotent stem cells (iPSCs) in the presence of a conditioned medium (CM) of cancer-derived cells. The CSCs were characterized by the formation of malignant tumors in vivo, followed by metastasis. In this study, CSCs converted from mouse iPSCs in the presence of CM from hepatocellular carcinoma (HCC) cell line Huh7 cells. These converted cells (miPS-Huh7cm cells) were established as the metastatic cells. The generated CSCs were injected into the liver or spleen of nude mice. Almost one month after transplantation, the tumors were excised, and the primary cultured cells derived from the malignant tumors and metastatic nodules were evaluated by stemness and metastatic markers to compare their differences. The miPS-Huh7cm cells exhibited metastatic potential, and efficiently formed malignant tumors with lung and/or liver lesions in vivo, whereas the injected miPS formed teratoma. The primary cultured cells derived from the malignant tumors and metastatic nodules sustained the expression of stemness markers, such as Nanog, Klf4 and c-Myc, and acquired cancer stem markers, such as CD90, CD44 and ALDH1. Simultaneously, the expression of metastatic markers, such as Slug, Twist1 and vimentin, in primary cells derived from the malignant tumors, was higher than in metastatic nodules. The CSCs derived from iPSCs, forming malignant tumors and displaying high metastasis, will provide a good animal model to study the mechanisms of metastasis.

Cancer stem cell induction from mouse embryonic stem cells.

Although cancers are often removed by surgery and treated by chemotherapy and/or radiation therapies, they often reoccur following treatment due to the presence of resistant residual cells such as cancer stem cells (CSCs). CSCs are characterized by their self-renewal, pluripotency, and tumorigenicity properties, and are promising therapeutic targets for the complete therapy of cancers; however, the number of CSCs in cancer tissue is typically too small to investigate fully. We have previously reported that CSCs could be established from induced pluripotent stem cells (iPSCs) using a conditioned medium during cancer cell culture. In the present study, mouse embryonic stem cells (mESCs) were observed to be converted to CSCs (mES-CSCs). This demonstrated that CSC induction does not exclusively occur following gene editing in somatic cells, and that conditioned medium from cancer cells may contain factors that can induce CSCs. Therefore, not only iPSCs but also mESCs, were demonstrated to be able to produce CSCs as one of the potentials of pluripotency of stem cells, suggesting that the conversion to CSCs is not specific to iPSCs. The resultant mES-CSCs would be also useful to generate tissue specific cancers and these naturally occurring cancers can contribute to drug screenings, but also undergo further investigation in order to reveal cancer mechanisms.

Method to Convert Stem Cells into Cancer Stem Cells.

The cancer stem cell (CSC) hypothesis suggests that tumors are sustained exclusively by a small population of the cells with stem cell properties. CSCs have been identified in most tumors and are responsible for the initiation, recurrence, and resistance of different cancers. In vitro CSC models will be of great help in revisiting the mechanism of cancer development, as well as the tumor microenvironment and the heterogeneity of cancer and metastasis. Our group recently described the generation of CSCs from induced pluripotent stem cells (iPSCs), which were reprogrammed from normal cells, and/or embryonic stem cells (ESCs). This procedure will improve the understanding of the essential niche involved in cancer initiation. The composition of this cancer-inducing niche, if identified, will let us know how normal cells convert to malignant in the body and how, in turn, cancer prevention could be achieved. Further, once developed, CSCs demonstrate the ability to differentiate into endothelial cells, cancer-associated fibroblasts, and other phenotypes establishing the CSC niche. These will be good materials for developing novel cancer treatments. In this protocol, we describe how to handle mouse iPSCs/ESCs and how to choose the critical time for starting the conversion into CSCs. This CSC generation protocol is essential for understanding the role of CSC in cancer initiation and progress.

[Results of Palliative Resection in an Elderly Colorectal Cancer Patient].

With the aging of society, surgery for elderly colorectal cancer(CRC)patients is also increasing. We examined 11 elderly CRC patients who underwent palliative resection in our institute. The reasons other than age for which palliative resection was chosen, included dementia, basic disease, and social backgrounds such as living alone, etc. Although surgery was possible according to the ECOG PS and other examinations before surgery, 3 patients(27.3%)who developed respiratory or circulatory complications after surgery died in the hospital. From the viewpoint of retrospective P-POSSUM evaluation, unreasonable surgical decisions were not made. However, recovery was difficult once complications occurred in the subject group. The postoperative hospital stay, excluding inpatient deaths, was over 1 month due to rehabilitation, discharge adjustment, etc. Therefore, palliative treatment other than surgery should be considered for elderly CRC patients.

Randomized phase III trial of gastrectomy with or without neoadjuvant S-1 plus cisplatin for type 4 or large type 3 gastric cancer, the short-term safety and surgical results: Japan Clinical Oncology Group Study (JCOG0501).

BACKGROUND: The prognosis of patients with linitis plastica (type 4) and large (≥ 8 cm) ulcero-invasive-type (type 3) gastric cancer is extremely poor, even after extended surgery and adjuvant chemotherapy. Given the promising results of our previous phase II study evaluating neoadjuvant chemotherapy (NAC) with S-1 plus cisplatin (JCOG0210), we performed a phase III study to confirm the efficacy of NAC in these patients, with the safety and surgical results are presented here. METHODS: Eligible patients were randomized to gastrectomy plus adjuvant chemotherapy with S-1 (Arm A) or NAC followed by gastrectomy + adjuvant chemotherapy (Arm B). The primary endpoint was the overall survival (OS). This trial is registered at the UMIN Clinical Trials Registry as C000000279. RESULTS: From February 2007 to July 2013, 300 patients were randomized (Arm A 149, Arm B 151). NAC was completed in 133 patients (88%). Major grade 3/4 adverse events during NAC were neutropenia (29.3%), nausea (5.4%), diarrhea (4.8%), and fatigue (2.7%). Gastrectomy was performed in 147 patients (99%) in Arm A and 139 patients (92%) in Arm B. The operation time was significantly shorter in Arm B than in Arm A (median 255 vs. 240 min, respectively; p = 0.024). There were no significant differences in Grade 2-4 morbidity and mortality (25.2% and 1.3% in Arm A and 15.8% and 0.7% in Arm B, respectively). CONCLUSIONS: NAC for type 4 and large type 3 gastric cancer followed by D2 gastrectomy can be safely performed without increasing the morbidity or mortality.

Single-arm confirmatory trial of laparoscopy-assisted total or proximal gastrectomy with nodal dissection for clinical stage I gastric cancer: Japan Clinical Oncology Group study JCOG1401.

BACKGROUNDS: Laparoscopy-assisted distal gastrectomy (LADG) for gastric cancer is safe and feasible. In contrast, no prospective study evaluating the safety and efficacy of laparoscopy-assisted total gastrectomy (LATG) or laparoscopy-assisted proximal gastrectomy (LAPG) has been completed. We conducted a single-arm confirmatory trial to evaluate the safety of LATG/LAPG for clinical stage I (T1N0/T1N1/T2N0) proximal gastric cancer. METHODS: The extent of lymphadenectomy was selected based on the Japanese Gastric Cancer Treatment Guidelines. The mini-laparotomy incision was required to be ≤ 6 cm. The primary endpoint was the proportion of grade 2-4 (CTCAE ver. 4.0) esophagojejunal anastomotic leakage. The planned sample size was 245 considering a threshold of 8% and one-sided alpha of 2.5%. RESULTS: Between April 2015 and February 2017, 244 eligible patients were enrolled. LATG/LAPG was performed in 195/49. The proportion of conversions was 1.7%. Clinical T1N0/T1N1/T2N0 was 212/9/23. The extents of lymphadenectomy were as follows: D1+: 229; D2: 15. The median operation time was 309 min (IQR 265-353). The median blood loss was 30 ml (IQR 10-86). Grade 2-4 esophagojejunal anastomotic leakage was 2.5% (6/244; 95% CI 0.9-5.3). The overall proportion of in-hospital grade 3-4 adverse events was 29% (71/244). The proportions of intraabdominal abscess and pancreatic fistula were 3.7% and 2.0%, respectively. There were no treatment-related deaths. CONCLUSIONS: This trial confirmed the safety of LATG/LAPG. After the non-inferiority of LADG is confirmed in our phase III trial (JCOG0912), LATG/LAPG is expected to be established as one of the standard treatments for clinical stage I gastric cancer.

Xanthogranulomatous pyelonephritis with psoas abscess and renocolic fistula.

Xanthogranulomatous pyelonephritis (XGP) is an uncommon inflammatory disease of the kidney 1. Diffuse XGP is a rare condition which may spread into the pelvic cavity leading to fatal complications from a psoas muscle abscess and/or renocolic fistula 2. In diffuse type, nephrectomy and excision of the fistula is the recommended treatment.

Effect of early oral feeding on length of hospital stay following gastrectomy for gastric cancer: a Japanese multicenter, randomized controlled trial.

PURPOSE: This multicenter, randomized controlled study evaluates the safety of early oral feeding following gastrectomy, and its effect on the length of postoperative hospital stay. METHODS: The subjects of this study were patients who underwent distal gastrectomy (DG) or total gastrectomy (TG) for gastric cancer between January 2014 and December 2015. Patients were randomly assigned to the early oral feeding group (intervention group) or the conventional postoperative management group (control group) for each procedure. We evaluated the length of postoperative hospital stay and the incidence of postoperative complications in each group. RESULTS: No significant differences in length of postoperative stay were found between the intervention and control groups of the patients who underwent DG. The incidence of postoperative complications was significantly greater in the DG intervention group. In contrast, the length of postoperative stay was significantly shorter in the TG intervention group, although the TG group did not attain the established target sample size. CONCLUSION: Early oral feeding did not shorten the postoperative hospital stay after DG. The higher incidence of postoperative complications precluded the unselected adoption of early oral feeding for DG patients. Further confirmative studies are required to definitively establish the potential benefits of early oral feeding for TG patients.

Bursectomy versus omentectomy alone for resectable gastric cancer (JCOG1001): a phase 3, open-label, randomised controlled trial.

BACKGROUND: The role of bursectomy, in which the peritoneal lining covering the pancreas and the anterior plane of the transverse mesocolon are dissected, has long been controversial for preventing peritoneal metastasis. We investigated the survival benefit of bursectomy in patients with resectable gastric cancer. METHODS: This phase 3, open-label, randomised controlled trial was done at 57 hospitals in Japan. Patients aged 20-80 years who had cT3(SS)-cT4a(SE) histologically proven gastric adenocarcinoma with an Eastern Cooperative Oncology Group performance status of 0 or 1 and body-mass index less than 30 kg/m2 and who did not have distant metastasis or bulky lymph nodes were randomly assigned (1:1) during surgery to receive omentectomy alone (non-bursectomy) or bursectomy. Randomisation was done by telephone or website to the Japan Clinical Oncology Group Data Center and used a minimisation method with a random component to adjust for institution, cT status (T3 vs T4a), and type of gastrectomy (distal vs total). Both groups had total or distal gastrectomy with D2 lymphadenectomy. The primary endpoint was overall survival, analysed in the intention-to-treat population. The study is registered with UMIN-CTR, number UMIN000003688. FINDINGS: Between June 1, 2010, and March 30, 2015, 1503 patients were enrolled based on preoperative inclusion and exclusion criteria. Intraoperative inclusion and exclusion criteria were met in 1204 patients, of which 602 were allocated to the non-bursectomy group and 602 were allocated to the bursectomy group. At the planned second interim analysis on Sept 17, 2016, the JCOG Data and Safety Monitoring Committee independently reviewed the results and recommended their early publication on the basis of futility because overall survival was lower in the bursectomy group than the non-bursectomy group, and because the predictive probability of overall survival being significantly higher in bursectomy than non-bursectomy patients at the final analysis was only 12·7%. 5-year overall survival was 76·7% (95% CI 72·0-80·6) in the non-bursectomy group and 76·9% (72·6-80·7) in the bursectomy group (hazard ratio 1·05, 95% CI 0·81-1·37, one-sided p=0·65). 64 (11%) of 601 in the non-bursectomy group and 77 (13%) of 600 patients in the bursectomy group had grade 3-4 operative morbidity. Pancreatic fistula was significantly more common in the bursectomy group than in the non-bursectomy group (29 [5%] vs 15 [2%]; p=0·032). Six deaths occurred either in hospital or within 1 month of surgery: five in the non-bursectomy group and one in the bursectomy group. INTERPRETATION: Bursectomy did not provide a survival advantage over non-bursectomy. D2 dissection with omentectomy alone should be done as a standard surgery for resectable cT3-T4a gastric cancer. FUNDING: Japan Agency for Medical Research and Development, the Ministry of Health, Labour and Welfare of Japan, and the National Cancer Centre Research and Development Fund.

Up-Regulation of PI 3-Kinases and the Activation of PI3K-Akt Signaling Pathway in Cancer Stem-Like Cells Through DNA Hypomethylation Mediated by the Cancer Microenvironment.

Previously, we have succeeded in converting induced pluripotent stem cells (iPSCs) into cancer stem cells (CSCs) by treating the iPSCs with conditioned medium of Lewis lung carcinoma (LLC) cells. The converted CSCs, named miPS-LLCcm cells, exhibited the self-renewal, differentiation potential, and potential to form malignant tumors with metastasis. In this study, we further characterized miPS-LLCcm cells both in vivo and in vitro. The tumors formed by subcutaneous injection showed the structures with pathophysiological features consisting of undifferentiated and malignant phenotypes generally found in adenocarcinoma. Metastasis in the lung was also observed as nodule structures. Excising from the tumors, primary cultured cells from the tumor and the nodule showed self-renewal, differentiation potential as well as tumor forming ability, which are the essential characters of CSCs. We then characterized the epigenetic regulation occurring in the CSCs. By comparing the DNA methylation level of CG rich regions, the differentially methylated regions (DMRs) were evaluated in all stages of CSCs when compared with the parental iPSCs. In DMRs, hypomethylation was found superior to hypermethylation in the miPS-LLCcm cells and its derivatives. The hypo- and hypermethylated genes were used to nominate KEGG pathways related with CSC. As a result, several categories were defined in the KEGG pathways from which most related with cancers, significant and high expression of components was PI3K-AKT signaling pathway. Simultaneously, the AKT activation was also confirmed in the CSCs. The PI3K-Akt signaling pathway should be an important pathway for the CSCs established by the treatment with conditioned medium of LLC cells.