Senescent Fibroblasts Potentiate Peritoneal Metastasis of Diffuse-type Gastric Cancer Cells via IL-8-mediated Crosstalk.

BACKGROUND/AIM: Diffuse-type gastric cancer (DGC) often forms peritoneal metastases, leading to poor prognosis. However, the underlying mechanism of DGC-mediated peritoneal metastasis is poorly understood. DGC is characterized by desmoplastic stroma, in which heterogeneous cancer-associated fibroblasts (CAFs), including myofibroblastic CAFs (myCAFs) and senescent CAFs (sCAFs), play a crucial role during tumor progression. This study investigated the CAF subtypes induced by GC cells and the role of sCAFs in peritoneal metastasis of DGC cells. MATERIALS AND METHODS: Conditioned medium of human DGC cells (KATOIII, NUGC-4) and human intestinal-type GC (IGC) cells (MKN-7, N87) was used to induce CAFs. CAF subtypes were evaluated by analyzing the expression of α-smooth muscle actin (α-SMA), senescence-associated ß-galactosidase (SA-ß-gal), and p16 in human normal fibroblasts (GF, FEF-3). A cytokine array was used to explore the underlying mechanism of GC-induced CAF subtype development. The role of sCAFs in peritoneal metastasis of DGC cells was analyzed using a peritoneally metastatic DGC tumor model. The relationships between GC subtypes and CAF-related markers were evaluated using publicly available datasets. RESULTS: IGC cells significantly induced α-SMA+ myCAFs by secreting transforming growth factor-ß, whereas DGC cells induced SA-ß-gal+/p16+ sCAFs by secreting interleukin (IL)-8. sCAFs further secreted IL-8 to promote DGC cell migration. In vivo experiments demonstrated that co-inoculation of sCAFs significantly enhanced peritoneal metastasis of NUGC-4 cells, which was attenuated by administration of the IL-8 receptor antagonist navarixin. p16 and IL-8 expression was significantly associated with poor prognosis of DGC patients. CONCLUSION: sCAFs promote peritoneal metastasis of DGC via IL-8-mediated crosstalk.

A multi-center, prospective, clinical study to evaluate the anti-reflux efficacy of laparoscopic double-flap technique (lD-FLAP Study).

Background: Double-flap technique (DFT) is a reconstruction procedure after proximal gastrectomy (PG). We previously reported a multi-center, retrospective study in which the incidence of reflux esophagitis (RE) (Los Angeles Classification ≥Grade B [LA-B]) 1 year after surgery was 6.0%. There have been many reports, but all of them were retrospective. Thus, a multi-center, prospective study was conducted. Methods: Laparoscopic PG + DFT was performed for cT1N0 upper gastric cancer patients. The primary endpoint was the incidence of RE (≥LA-B) 1 year after surgery. The planned sample size was 40, based on an estimated incidence of 6.0% and an upper threshold of 20%. Results: Forty patients were recruited, and 39, excluding one with conversion to total gastrectomy, received protocol treatment. Anastomotic leakage (Clavien-Dindo ≥Grade III) was observed in one patient (2.6%). In 38 patients, excluding one case of postoperative mortality, RE (≥LA-B) was observed in two patients (5.3%) 1 year after surgery, and the upper limit of the 95% confidence interval was 17.3%, lower than the 20% threshold. Anastomotic stricture requiring dilatation was observed in two patients (5.3%). One year after surgery, body weight change was 88.9 ± 7.0%, and PNI <40 and CONUT ≥5, indicating malnutrition, were observed in only one patient (2.6%) each. In the quality of life survey using the PGSAS-45 questionnaire, the esophageal reflux subscale score was 1.4 ± 0.6, significantly better than the public data (2.0 ± 1.0; p = 0.001). Conclusion: Laparoscopic DFT showed anti-reflux efficacy. Taken together with the acceptable incidence of anastomotic stricture, DFT can be an option for reconstruction procedure after PG.

Intraperitoneal Administration of p53-armed Oncolytic Adenovirus Inhibits Peritoneal Metastasis of Diffuse-type Gastric Cancer Cells.

BACKGROUND/AIM: Diffuse-type gastric cancer (GC) frequently exhibits peritoneal metastasis, leading to poor prognosis. However, efforts to develop antitumor strategies for preventing the peritoneal metastasis of GC have been unsuccessful. As diffuse-type GC cells often carry a genetic alteration in the tumor suppressor p53 gene, p53 restoration may be a potent strategy for preventing peritoneal metastasis of GC. In this study, we investigated the therapeutic potential of p53-expressing adenoviral vectors against peritoneal metastasis of diffuse-type GC cells. MATERIALS AND METHODS: Three diffuse-type human GC cell types with different p53 statuses (p53-wild type NUGC-4, p53-mutant type GCIY, and p53-null type KATOIII) were used to evaluate the therapeutic potential of p53 activation induced by the p53-expressing, replication-deficient adenovirus Ad-p53 and oncolytic adenovirus OBP-702. Viability, apoptosis, and autophagy of virus-treated GC cells were analyzed under normal and sphere-forming culture conditions using the XTT assay and western blot analysis. The in vivo antitumor effects of OBP-702 and Ad-p53 were assessed using xenograft tumor models involving peritoneal metastasis of NUGC-4 and GCIY cells. RESULTS: Under normal and sphere-forming culture conditions, OBP-702 induced a significantly greater antitumor effect in GC cells compared with Ad-p53 by strongly inducing p53-mediated apoptosis and autophagy and receptor tyrosine kinase suppression. In vivo experiments demonstrated that intraperitoneal administration of OBP-702 significantly suppressed the peritoneal metastasis of NUGC-4 and GCIY cells compared with Ad-p53, leading to prolonged survival of mice. CONCLUSION: Intraperitoneal administration of OBP-702 inhibits the peritoneal metastasis of GC cells by inducing p53-mediated cytopathic activity.

Survival Impact of Postoperative Skeletal Muscle Loss in Gastric Cancer Patients Who Underwent Gastrectomy.

BACKGROUND/AIM: It has recently been recognized that preoperative sarcopenia contributes to postoperative complications and overall survival in gastric cancer (GC). However, few studies have investigated the relationship between postoperative skeletal muscle loss (SML) and survival in GC, despite the inevitability of body weight loss after gastrectomy in most GC patients. Herein, we studied the impact of postoperative SML on GC prognosis. PATIENTS AND METHODS: A total of 370 patients with GC who underwent curative gastrectomy were retrospectively evaluated in this study. Postoperative SML was assessed on computed tomography (CT) images taken before surgery and 1 year after surgery. The impact of postoperative SML on survival was evaluated. RESULTS: Postoperative severe SML was significantly associated with presence of comorbidities, higher tumor stage, higher postoperative complication rate and longer hospital stay. Univariate and multivariate analyses of prognostic factors for overall survival revealed that SML was an independent indicator of poor prognosis, along with age, tumor stage, preoperative sarcopenia, and operation time (hazard ratio, 2.65; 95% confidence interval, 1.68-4.20, p<0.0001). There was a strong association of severe postoperative SML with decreased overall survival in patients with preoperative sarcopenia. CONCLUSION: To improve the prognosis of GC patients after surgery, it is important to prevent postoperative SML as well as preoperative sarcopenia. Perioperative multimodal interventions including nutritional counseling, oral nutritional supplements, and exercise are required to prevent SML after gastrectomy.

Surgical technique of suprapancreatic D2 lymphadenectomy focusing on the posterior hepatic plexus for advanced gastric cancer.

PURPOSE: Although D2 lymphadenectomy is currently considered a standard procedure for advanced gastric cancer (GC) worldwide, there is room for discussion about the appropriate range of suprapancreatic D2 lymphadenectomy. Focusing on the posterior hepatic plexus (PHP), which is not well recognized, we developed a surgical technique of suprapancreatic D2 lymphadenectomy, which we have called PHP-D2, and its short-term and long-term efficacies were evaluated in comparison with non-PHP-D2. METHODS: GC patients who underwent distal gastrectomy with D2 lymphadenectomy between July 2006 and May 2013 were enrolled, from which patients who had peritoneal metastasis and/or were peritoneal cytology-positive during surgery were excluded. Their medical records were retrospectively reviewed. RESULTS: Ninety-two patients (non-PHP-D2: 48, PHP-D2: 44) were enrolled. Shorter operation time (330 min vs 275 min, p < 0.0001) and less blood loss (290 mL vs 125 mL, p < 0.0001) were observed in PHP-D2, and no pancreatic fistulas were observed in PHP-D2. More lymph nodes of #11p (1 vs 1.5, p = 0.0328) and #12a lymph nodes (0 vs 1, p = 0.0034) were retrieved in PHP-D2, with no significant differences in #8a and #9 lymph nodes. Lymphatic recurrence was significantly less in PHP-D2 (p = 0.0166), and univariate and multivariate analyses showed that non-PHP-D2 was a significant risk factor for lymphatic recurrence (p = 0.0158), although there were no significant differences between non-PHP-D2 and PHP-D2 in 5-year overall survival and 5-year relapse-free survival. CONCLUSION: PHP-D2 was a safe and feasible procedure that had the potential to reduce lymphatic recurrence, and it can be a standard procedure of D2 lymphadenectomy for advanced GC.

SMAD4 Germline Pathogenic Variant-Related Gastric Juvenile Polyposis with Adenocarcinoma Treated with Laparoscopic Total Gastrectomy: A Case Report.

BACKGROUND Juvenile polyposis syndrome is an uncommon, autosomal-dominant hereditary disease that is distinguished by multiple polyps in the stomach or intestinal tract. It is associated with a high risk of malignancy. Pathogenic variants in SMAD4 or BMPR1A account for 40% of all cases. CASE REPORT A 49-year-old woman underwent esophagogastroduodenoscopy because of exacerbation of anemia. She had numerous erythematous polyps in most parts of her stomach. Based on biopsy findings, juvenile polyposis syndrome (JPS) was suspected morphologically, but there was no evidence of malignancy. Colonoscopy showed stemmed hyperplastic polyps and an adenoma; video capsule endoscopy revealed no lesions in the small intestine. After preoperative surveillance, laparoscopic total gastrectomy with D1 lymph node dissection was performed to prevent malignant transformation. The pathological diagnosis was juvenile polyp-like polyposis with adenocarcinoma. In addition, a germline pathogenic variant in the SMAD4 gene was detected with genetic testing. CONCLUSIONS JPS can be diagnosed with endoscopy and genetic testing. Further, appropriate surgical management may prevent cancer-related death in patients with this condition.

Accreditation as a qualified surgeon improves surgical outcomes in laparoscopic distal gastrectomy.

PURPOSE: The Endoscopic Surgical Skill Quantification System for qualified surgeons (QSs) was introduced in Japan to improve surgical outcomes. This study reviewed the surgical outcomes after initial experience performing laparoscopic distal gastrectomy (LDG) and evaluated the improvement in surgical outcomes following accreditation as a QS. METHODS: Eighty-seven consecutive patients who underwent LDG for gastric cancer by a single surgeon were enrolled in this study. The cumulative sum method was used to analyze the learning curve for LDG. The surgical outcomes were evaluated according to the two phases of the learning curve (learning period vs. mastery period) and accreditation (non-QS period vs. QS period). RESULTS: The learning period for LDG was 48 cases. Accreditation was approved at the 67th case. The operation time and estimated blood loss were significantly reduced in the QS period compared to the non-QS period (230 vs. 270 min, p < 0.001; 20.5 vs. 59.8 ml, p = 0.024, respectively). Furthermore, the major complication rate was significantly lower in the QS period than in the non-QS period (0 vs. 10.6%, p = 0.044). CONCLUSIONS: Experience performing approximately 50 cases is required to reach proficiency in LDG. After receiving accreditation as a QS, the surgical outcomes, including the complication rate, were improved.

Long-term survival without recurrence after surgery for gastric yolk sac tumor-like carcinoma: a case report.

BACKGROUND: Gastric yolk sac tumor (YST)-like carcinoma is extremely rare, and its prognosis is poor, because most patients have widespread metastases at the time of diagnosis. We report a case of gastric YST-like carcinoma with an adenocarcinoma component without metastases in which curative resection was performed. CASE PRESENTATION: A 77-year-old man complaining of melena and dizziness due to anemia was diagnosed with poorly differentiated adenocarcinoma in the gastric cardia, with a benign ulcer in the gastric body. He underwent total gastrectomy with D2 lymph node dissection for the tumor. Histological examination of the resected specimens revealed a mixture of reticular and glandular neoplastic components morphologically. In the reticular area, an endodermal sinus pattern and some Schiller-Duval bodies were confirmed. Gastric YST-like carcinoma with adenocarcinoma components, T2N0M0 Stage IB, was diagnosed. Immunohistochemical analysis showed that the YST was positive for carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP) and p53. In contrast, the adenocarcinoma was positive for p53 and negative for CEA and AFP. The patient remained healthy as of 7 years postoperatively, with no recurrence. CONCLUSIONS: Routine medical examinations or endoscopic examinations for accidental symptom may be helpful for early diagnosis and good prognosis for gastric YST-like carcinoma, although the prognosis is generally poor.

Long-term Survival with a Rare Advanced Primary Gastrointestinal Malignant Melanoma Treated with Laparoscopic Surgery/Immune Checkpoint Inhibitor.

Targeted therapies for malignant melanoma have improved patients' prognoses. A primary gastrointestinal malignant melanoma is very rare, with no standard treatment strategy. We treated a 78-year-old Japanese female with advanced primary gastrointestinal melanoma of the descending colon and gallbladder. We administered a multidisciplinary treatment: surgical resection of the descending colon and gallbladder tumors, resection of the metastatic lymph nodes behind the pancreas head, and immune checkpoint antibody-blockade therapy (nivolumab) for ~4 years. PET/CT demonstrated no recurrent lesion for > 3 years. Multidisciplinary therapies (e.g., surgery, chemotherapy, radiotherapy, target therapy, and immune checkpoint antibody-blockade therapy) can successfully treat primary gastrointestinal malignant melanoma.

Local oncolytic adenovirotherapy produces an abscopal effect via tumor-derived extracellular vesicles.

Extracellular vesicles (EVs) play important roles in various intercellular communication processes. The abscopal effect is an interesting phenomenon in cancer treatment, in which immune activation is generally considered a main factor. We previously developed a telomerase-specific oncolytic adenovirus, Telomelysin (OBP-301), and occasionally observed therapeutic effects on distal tumors after local treatment in immunodeficient mice. In this study, we hypothesized that EVs may be involved in the abscopal effect of OBP-301. EVs isolated from the supernatant of HCT116 human colon carcinoma cells treated with OBP-301 were confirmed to contain OBP-301, and they showed cytotoxic activity (apoptosis and autophagy) similar to OBP-301. In bilateral subcutaneous HCT116 and CT26 tumor models, intratumoral administration of OBP-301 produced potent antitumor effects on tumors that were not directly treated with OBP-301, involving direct mediation by tumor-derived EVs containing OBP-301. This indicates that immune activation is not the main factor in this abscopal effect. Moreover, tumor-derived EVs exhibited high tumor tropism in orthotopic HCT116 rectal tumors, in which adenovirus E1A and adenovirus type 5 proteins were observed in metastatic liver tumors after localized rectal tumor treatment. In conclusion, local treatment with OBP-301 has the potential to produce abscopal effects via tumor-derived EVs.

Efficacy and safety of short-term (3 days) enoxaparin in preventing venous thromboembolism after gastric cancer surgery: A single-center, prospective cohort study.

BACKGROUND: Pharmacologic prophylaxis such as enoxaparin for venous thromboembolism (VTE) is rarely used in Japan, even following abdominal cancer surgery, for which it is recommended in relevant guidelines (at least 7 days of use) along with mechanical prophylaxis with intermittent pneumatic compression. Reasons for enoxaparin's unpopularity include concerns over postoperative bleeding and its inconvenience in clinical practice. Here, we conducted a prospective clinical study of short-term (3 days) use of enoxaparin, which is considered to minimally impact postoperative management without increasing bleeding risk. METHODS: Gastric cancer patients who underwent gastrectomy received enoxaparin for 3 days from postoperative day (POD) 1-4. The primary endpoint was the incidence of deep vein thrombosis (DVT), which was examined primarily via Doppler ultrasonography of the lower limbs between POD 8 and 14. The planned sample size was 70, which was calculated based on an estimated incidence rate of 9% and an upper limit of incidence rate of 20%, with alpha of 0.05 and beta of 0.2. RESULTS: A total of 70 gastric cancer patients were enrolled, and ultimately, 68 patients received the protocol intervention and DVT evaluation. Sixty-seven patients completed 6 enoxaparin injections, but 1 patient did not complete the course due to abdominal bleeding after initiation. The incidence of DVT was 4.4% (3/68), and the 95% upper confidence interval was 12.2%, lower than the 20% threshold we set as the upper limit of DVT incidence. DVT was detected only in the peripheral veins of the lower extremities in all 3 affected patients. The incidence of bleeding-related complications, which were not severe, was 1.5% (1/68). CONCLUSIONS: Short-term (3 days) use of enoxaparin was shown to be effective and safe for VTE prophylaxis, comparable to regular use (at least 7 days), in postoperative management of gastric cancer surgery.

Intracorporeal semi-hand-sewn Billroth I reconstruction in total laparoscopic distal gastrectomy.

INTRODUCTION: Intracorporeal Billroth I (B-I) reconstruction using an endoscopic linear stapler (ELS) is widely performed in total laparoscopic distal gastrectomy. However, conventional procedures require many ELSs for anastomosis. Here, we introduce the novel intracorporeal semi-hand-sewn (SHS) B-I reconstruction. MATERIALS AND SURGICAL TECHNIQUE: After the transection of stomach and duodenum using ELS following adequate lymph node dissection, small entry holes were made on the anterior wall in the greater curvature of the stomach and the duodenal stump. The posterior walls of both the remnant stomach and the duodenum were attached with the ELS and fired to create the posterior wall of the B-I anastomosis. All the transection line of the duodenum and one-third of the transection line of the stomach were dissected; finally the anterior wall suturing at the anastomotic site was performed by the laparoscopic hand-sewn technique. DISCUSSION: SHS procedure was performed for 17 gastric cancer patients. There were no intraoperative complications or conversions to open surgery. One intra-abdominal abscess was observed although there was no anastomotic leakage. The median reconstruction time was 48 minutes (32-63). The SHS procedure was safe, feasible, and economical, although it requires sufficient laparoscopic suturing and ligation skill.

Short-term and long-term comparisons of laparoscopy-assisted proximal gastrectomy with esophagogastrostomy by the double-flap technique and laparoscopy-assisted total gastrectomy for proximal gastric cancer.

BACKGROUND: Although proximal gastrectomy (PG) is a recognized surgical procedure for early proximal gastric cancer, total gastrectomy (TG) is sometimes selected due to concern about severe gastroesophageal reflux. Esophagogastrostomy by the double-flap technique (DFT) is an anti-reflux reconstruction after PG, and its short-term effectiveness has been reported. However, little is known about the long-term effects on nutritional status and quality of life (QOL). METHODS: Gastric cancer patients who underwent laparoscopy-assisted PG (LAPG) with DFT or laparoscopy-assisted TG (LATG) between April 2011 and March 2014 were retrospectively analyzed. Body weight (BW), body mass index (BMI), and prognostic nutritional index (PNI) were reviewed to assess nutritional status, and the Postgastrectomy Syndrome Assessment Scale (PGSAS)-45 was used to assess QOL. RESULTS: A total of 36 patients (LATG: 17, LAPG: 19) were enrolled. Four of 17 LATG patients (24%) were diagnosed with Stage ≥II after surgery, and half received S-1 adjuvant chemotherapy. BW and PNI were better maintained in LAPG than in LATG patients until 1-year follow-up. Seven of 16 LATG patients (44%) were categorized as "underweight (BMI<18.5 kg/m2)" at 1-year follow-up, compared to three of 18 LAPG patients (17%; p = 0.0836). The PGSAS-45 showed no significant difference in all QOL categories except for decreased BW (p = 0.0132). Multivariate analysis showed that LATG was the only potential risk factor for severe BW loss (odds ratio: 3.03, p = 0.0722). CONCLUSIONS: LAPG with DFT was superior to LATG in postoperative nutritional maintenance, and can be the first option for early proximal gastric cancer.

Boosting Replication and Penetration of Oncolytic Adenovirus by Paclitaxel Eradicate Peritoneal Metastasis of Gastric Cancer.

Peritoneal metastasis is the most frequent form of distant metastasis and recurrence in gastric cancer, and the prognosis is extremely poor due to the resistance of systemic chemotherapy. Here, we demonstrate that intraperitoneal (i.p.) administration of a green fluorescence protein (GFP)-expressing attenuated adenovirus with oncolytic potency (OBP-401) synergistically suppressed the peritoneal metastasis of gastric cancer in combination with paclitaxel (PTX). OBP-401 synergistically suppressed the viability of human gastric cancer cells in combination with PTX. PTX enhanced the antitumor effect of OBP-401 due to enhanced viral replication in cancer cells. The combination therapy increased induction of mitotic catastrophe, resulting in accelerated autophagy and apoptosis. Peritoneally disseminated nodules were selectively visualized as GFP-positive spots by i.p. administration of OBP-401 in an orthotopic human gastric cancer peritoneal dissemination model. PTX enhanced the deep penetration of OBP-401 into the disseminated nodules. Moreover, a non-invasive in vivo imaging system demonstrated that the combination therapy of i.p. OBP-401 administration with PTX significantly inhibited growth of peritoneal metastatic tumors and the amount of malignant ascites. i.p. virotherapy with PTX may be a promising treatment strategy for the peritoneal metastasis of gastric cancer.

Immune Modulation by Telomerase-Specific Oncolytic Adenovirus Synergistically Enhances Antitumor Efficacy with Anti-PD1 Antibody.

The clinical benefit of monotherapy involving immune checkpoint inhibitors (ICIs) such as anti-programmed death-1 antibody (PD-1 Ab) is limited to small populations. We previously developed a telomerase-specific oncolytic adenovirus, Telomelysin (OBP-301), the safety of which was confirmed in a phase I clinical study. Here, we examined the potential of OBP-502, an OBP-301 variant, as an agent for inducing immunogenic cell death (ICD) and synergistically enhancing the efficacy of OBP-502 with PD-1 Ab using CT26 murine colon cancer and PAN02 murine pancreatic cancer cell lines. OBP-502 induced the release of ICD molecules such as adenosine triphosphate (ATP) and high-mobility group box protein 1 (HMGB1) from CT26 and PAN02 cells, leading to recruitment of CD8-positive lymphocytes and inhibition of Foxp3-positive lymphocyte infiltration into tumors. Combination therapy involving OBP-502 intratumoral administration and PD-1 Ab systemic administration significantly suppressed the growth of not only OBP-502-treated tumors but also tumors not treated with OBP-502 (so-called abscopal effect) in CT26 and PAN02 bilateral subcutaneous tumor models, in which active recruitment of CD8-positve lymphocytes was observed even in tumors not treated with OBP-502. This combined efficacy was similar to that observed in a CT26 rectal orthotopic tumor model involving liver metastases. In conclusion, telomerase-specific oncolytic adenoviruses are promising candidates for combined therapies with ICIs.

Induction chemoradiotherapy including docetaxel, cisplatin, and 5-fluorouracil for locally advanced esophageal cancer.

BACKGROUND: Locally advanced esophageal cancer (EC) invading surrounding organs (T4b) is difficult to treat. In general, definitive chemoradiotherapy (d-CRT) has been chosen as treatment for such cases. However, the outcome has not been good. Recently, the effectiveness of d-CRT with docetaxel, cisplatin, and 5-fluorouracil (DCF-RT) has been reported. Furthermore, surgery after d-CRT has a better prognosis than d-CRT alone in some reports, although it has a high risk of surgical complications. This study investigated the effectiveness and safety of induction DCF-RT. METHODS: The subjects were EC patients who underwent induction DCF-RT in Okayama University Hospital between January 2011 and December 2017. Their background characteristics, treatment details, histopathological factors, adverse events during CRT, postoperative complications, and overall survival (OS) were assessed. RESULTS: A total of 16 cases were performed induction DCF-RT. In 10 cases, death occurred, with 9 cancer-related deaths, and 1 death due to other disease. For all cases, OS was 37.5% at 3 years. 12 cases underwent esophagectomy after DCF-RT. Their OS was 50% at 3 years. 13 patients (81.3%) had Grade 3 febrile neutropenia. In 7 cases (62.5%), fasting for the treatment of diarrhea was needed. Three patients (25%) developed anastomotic leakage. Some recurrent laryngeal nerve paralysis was observed in 6 cases (50%). CONCLUSION: Although the rates of adverse events and surgical complications were slightly higher than in past reports, they were acceptable. It is useful to perform induction DCF-RT for T4b EC.

Visualization of epithelial-mesenchymal transition in an inflammatory microenvironment-colorectal cancer network.

Epithelial-mesenchymal transition (EMT) is a biological process by which epithelial cells acquire mesenchymal characteristics. In malignant tumors, EMT is crucial for acquisition of a mesenchymal phenotype with invasive and metastatic properties, leading to tumor progression. An inflammatory microenvironment is thought to be responsible for the development and progression of colorectal cancer (CRC); however, the precise role of inflammatory microenvironments in EMT-related CRC progression remains unclear. Here, we show the spatiotemporal visualization of CRC cells undergoing EMT using a fluorescence-guided EMT imaging system in which the mesenchymal vimentin promoter drives red fluorescent protein (RFP) expression. An inflammatory microenvironment including TNF-α, IL-1ß, and cytokine-secreting inflammatory macrophages induced RFP expression in association with the EMT phenotype in CRC cells. In vivo experiments further demonstrated the distribution of RFP-positive CRC cells in rectal and metastatic tumors. Our data suggest that the EMT imaging system described here is a powerful tool for monitoring EMT in inflammatory microenvironment-CRC networks.

Clinical Impact of Sarcopenia on Gastric Cancer.

Sarcopenia is a complex syndrome defined by progressive and generalized loss of skeletal muscle mass and strength. Although sarcopenia is mainly associated with aging, cancer is also one of its causes. Sarcopenia is now drawing attention as a poor prognostic factor in cancer. In patients with gastric cancer associated with eating disorders that often leads to loss of weight and muscle, sarcopenia is particularly important. Its definition and method of assessment, however, vary between studies, thus these need to be standardized. Nevertheless, emerging evidence suggests that sarcopenia contributes independently to postoperative complications and overall survival in gastric cancer. Interventions preventing sarcopenia with targeted nutrition and exercise are currently explored. This review aims to provide an understanding of sarcopenia, emphasizing its importance in the management of gastric cancer.

PD-L1 expression combined with microsatellite instability/CD8+ tumor infiltrating lymphocytes as a useful prognostic biomarker in gastric cancer.

While the importance of programmed death-ligand 1 (PD-L1), mutation burden caused by microsatellite instability (MSI), and CD8+ tumor infiltrating lymphocytes (TILs) has become evident, the significance of PD-L1 expression on prognosis still remains controversial. We evaluated the usefulness of combined markers of PD-L1 and MSI or CD8+ TILs as a prognostic biomarker in gastric cancer. A total of 283 patients with gastric cancer were reviewed retrospectively. PD-L1 expression on >5% tumor cells was defined as PD-L1-positive. PD-L1-positive rate was 15.5% (44/283). PD-L1 positivity was significantly correlated with invasive and advanced cancer and also significantly correlated with MSI, whereas no significance was observed with CD8+ TILs. Kaplan-Meier analysis showed that PD-L1 positivity significantly correlated with a poor prognosis (p = 0.0025). Multivariate analysis revealed that PD-L1 positivity was an independent poor prognostic factor (hazard ratio [HR]: 1.97, p = 0.0106) along with diffuse histological type and lymph node metastases. Combinations of PD-L1 and MSI (HR: 2.18) or CD8+ TILs (HR: 2.57) were stronger predictive factors for prognosis than PD-L1 alone. In conclusion, combined markers of PD-L1 and MSI or CD8+ TILs may be more useful prognostic biomarkers in gastric cancer, and better clarify the immune status of gastric cancer patients.