Systemic inflammation score as a preoperative prognostic factor for patients with pT2-T4 resectable gastric cancer: a retrospective study.

BACKGROUND: Systemic inflammation has been reported to be associated with cancer progression and metastasis. Systemic inflammation score (SIS), calculated from preoperative serum albumin level and lymphocyte-to-monocyte ratio, has been shown to be a novel prognostic factor for several types of tumors. This study aimed to evaluate the prognostic value of the SIS in patients with pT2-4 resectable gastric cancer (GC). METHODS: Total 97 patients with pT2-4 GC who underwent curative surgery from 322 cases between 2009 and 2015 in Fukushima Medical University Hospital were included. We performed univariate and multivariate analyses to evaluate the usefulness of preoperative SIS and other prognostic factors for relapse-free survival (RFS) and overall survival (OS). RESULTS: The higher SIS score was associated with undifferentiated cancer and recurrence. Univariate analysis of RFS identified deeper tumor invasion and higher SIS were significant risk factors and multivariate analysis revealed that both of them were independent prognostic factors for RFS. As for OS, age, tumor invasion, SIS and LNR were significantly correlated with RFS. In multivariate analysis, tumor invasion, SIS and LNR were independent prognostic factors for OS. CONCLUSIONS: SIS was an independent prognostic factor for RFS and OS in pT2-4 resectable gastric cancer patients who underwent curative gastrectomy.

SH2D4A downregulation due to loss of chromosome 8p is associated with poor prognosis and low T cell infiltration in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) develops through chromosomal instability (CIN) or microsatellite instability (MSI) due to deficient mismatch-repair (dMMR). We aimed to characterise novel cancer-associated genes that are downregulated upon malignant transformation in microsatellite stable (MSS) CRCs, which typically exhibit CIN with proficient mismatch-repair (pMMR). METHODS: Comprehensive screening was conducted on adenomas, MSI/MSS CRCs and cell lines, followed by copy number analysis, and their genetic and prognostic relevance was confirmed in microarray and RNA-seq cohorts (n = 3262, in total). Immunohistochemistry for SH2D4A was performed in 524 specimens of adenoma, carcinoma in situ and dMMR/pMMR CRC. The functional role of SH2D4A was investigated using CRC cell lines. RESULTS: A set of 11 genes, including SH2D4A, was downregulated during the adenoma-carcinoma sequence in MSS/CIN CRCs, mainly due to chromosome 8p deletions, and their negative prognostic impact was validated in independent cohorts. All adenomas were SH2D4A positive, but a subset of CRCs (5.3%) lacked SH2D4A immunohistochemical staining, correlating with poor prognosis and scarce T cell infiltration. SH2D4A depletion did not affect cell proliferation or IL-6-induced STAT3 phosphorylation. CONCLUSIONS: Our findings suggest that downregulation of multiple genes on chromosome 8p, including SH2D4A, cooperatively contribute to tumorigenesis, resulting in the immune cold tumour microenvironment and poor prognosis.

Incidence of upper extremity deep vein thrombosis in the retrosternal reconstruction after esophagectomy.

BACKGROUND: Upper extremity deep vein thrombosis (UEDVT) is relatively rare but cannot be negligible because it can cause fatal complications. Although it is reported that the occurrence rate of UEDVT has increased due to central venous catheter (CVC), cancer, and surgical invasion, there is still limited information for esophagectomy. The aim of this study was to evaluate the clinical factors, including CVC placement and thromboprophylaxis approach, as well as retrosternal space's width as a predictive factor for UEDVT in patients receiving esophagectomy. METHODS: This study included 66 patients who underwent esophagectomy with retrosternal reconstruction using a gastric tube. All patients routinely underwent contrast-enhanced computed tomography (CT) on the 4th postoperative day. Low-molecular-weight-heparin (LMWH) was routinely administered by the 2nd postoperative day. To evaluate retrosternal space's width, (a) The distance from sternum to brachiocephalic artery and (b) the distance from sternum to vertebra were measured by preoperative CT, and the ratio of (a) to (b) was defined as the width of retrosternal space. RESULTS: Among all patients, 11 (16.7%) suffered from UEDVT, and none was preoperatively received CVC placement, while 7 were inserted in non-UEDVT cases. Retrosternal space's width in patients with UEDVT was significantly smaller than that in patients without UEDVT (0.17 vs. 0.26; P < 0.0001). A cutoff value of the width was 0.21, which has high sensitivity (87%) and specificity (82%) for UEDVT prediction, respectively. CONCLUSION: The existence of CVC may not affect the development of UEDVT, but preoperative evaluation of retrosternal ratio may predict the occurrence of UEDVT.

Functional benefits of the double flap technique after proximal gastrectomy for gastric cancer.

BACKGROUND: Proximal gastrectomy is a widely performed procedure that has become more common with an increasing number of proximal gastric cancer cases. Several types of reconstructive procedures after proximal gastrectomy have been developed, and it remains controversial which procedure is the most advantageous with regard to the preservation of postoperative gastric stump function and nutritional status. In the present study, we retrospectively analyzed reconstructive procedures in a consecutive case series for proximal gastrectomy, primarily focusing on postoperative body weight maintenance, nutritional status, and gastric remnant functional preservation. METHODS: We enrolled 69 patients who had undergone proximal gastrectomy for gastric cancer in our institute between 2005 and 2020. Short-term complications, preservation of gastric remnant functions, nutritional status, and post-operative weight changes were compared. RESULTS: After proximal gastrectomy, the numbers of patients who underwent direct esophago-gastrostomy, jejunal interposition, double tract reconstruction, and the double flap technique were 9, 10, 14, and 36, respectively. The patients in whom the double flap technique was performed suffered no reflux esophagitis after surgery. Prevalence of gastric residual at 12 months after surgery was lowest in the double flap technique group. Moreover, the double flap technique group had a better tendency regarding post-operative changes of serum albumin ratios. Furthermore, the post-operative body weight change ratio of the double flap technique group was smallest among all groups and was significantly better than that of the double tract group. CONCLUSIONS: The double flap technique after proximal gastrectomy was considered the most effective technique for reconstruction which leads to better bodyweight maintenance, and results in less reflux esophagitis.

[A Case of Laparoscopic Surgery for Preoperatively Diagnosed Gastric Metastasis of Lung Cancer].

The patient was a 66-year-old male who had undergone an operation for lung cancer and solitary brain metastases. Follow- up PET-CT after 1 year detected FDG accumulation in the stomach. We performed esophagogastroscopy and found an approximately 20 mm-sized Type 2 tumor on the greater curvature of the upper stomach. A pathological diagnosis of lung adenocarcinoma metastasis in the stomach was made. Laparoscopic surgery was performed on the metastatic lesion to prevent bleeding and perforation, and resection was achieved with minimal invasion. The current development of chemotherapy, including immunotherapy, has contributed to the improved prognosis of cancer patients, including those with lung metastasis in the stomach. Considering these backgrounds, preventive surgical resection under laparoscopy may be an effective approach for improving prognosis and preventing acute life-threatening adverse events. We report this case along with a literature review.

Circulating tumor cells after neoadjuvant chemotherapy are related with recurrence in esophageal squamous cell carcinoma.

BACKGROUND: Circulating tumor cells (CTCs) are known to be a systemic process of malignant progression of cancer cells and there is a possibility that analysis for CTCs as a liquid biopsy become predictive or prognostic tools for cancer patients. METHODS: In the present study with the novel CTCs detection system (Celsee system®), we performed quantitative and qualitative analysis of CTCs in patients with esophageal squamous cell carcinoma (ESCC) receiving neoadjuvant chemotherapy (NAC) with 5FU + CDDP regimen. CTCs are defined as having both DAPI positive and CD45 negative. Vimentin-positive CTCs were defined as mesenchymal-type CTCs (M-CTCs), while epithelial-type CTCs (E-CTCs) were only positive for pan-cytokeratin. RESULTS: At the baseline, there are detectable amounts of CTCs in all patients (n = 30) at all stages, and there were no significant differences of total CTCs, E-CTCs, or M-CTCs numbers between stages. Of importance, among total CTCs, M-CTCs are more dominant than E-CTCs in number. Also, there was no significant change of detectable amounts and phenotype of CTCs before and after NAC (n = 24). Of note, early recurrent group indicated that there was an elevated total CTCs number before NAC and an increased M-CTCs after NAC in comparison to those in non-recurrent group. CONCLUSIONS: Quantitative and qualitative analysis of CTCs may provide useful complementary predictive and prognostic information in ESCC.

[A Case Receiving Gastric Tube Resection for the Recurrence after a Proton Beam Irradiation in a Patient with Gastric Tube Cancer after Esophagectomy].

A 74-year-oldman underwent transthoracic esophagectomy andgastric tube reconstruction for esophageal cancer 15 years ago. Eleven years after the esophagectomy, he was diagnosedwith gastric tube cancer. He receivedproton beam irradiation therapy. Macroscopic clinical effect revealed complete response at that time. Four years later, due to his discomfort symptom, he was diagnosedwith recurrent gastric tube cancer. Total resection of the gastric tube was performedat our hospital. In pathology findings, poorly differentiated adenocarcinoma was found at the proton beam irradiated part with multiple lymph node metastases in the omentum. He died 8 months postoperatively because of carcinomatous pleurisy. Periodic screening of the gastric tube and early detection of gastric tube cancer at early stage are important.

[A Case of Rectal Colon Cancer with Paraneoplastic Cerebellar Degeneration].

A case complicated with colorectal and prostate cancers in paraneoplastic(subacute)cerebellar degeneration(PCD)is extremely rare. We report a retrospective case of rectal carcinoma with paraneoplastic cerebellar degeneration. A 79-year-old man with Parkinson's disease was unable to walk because of paralysis. Brain MRI showed cerebellar atrophy. He was admitted to our hospital for anal bleeding and was diagnosed with colon cancer. An associated diagnosis of PCD was made. After resection, his paralysis and dysarthria were resolved to the extent of beingable to walk and speak fluently. Brain MP-RAGE showed no findings suggestive of metastasis or atrophy. He was treated surgically, which resulted in a transient improvement in PCD symptoms. Per blood testing, cytokines IL-6 and IL-10 were lower postoperatively. Immunosuppressive levels of myeloid- derived suppressor cells(MDSCs)were lower compared with the preoperative values. Thus, innate immunocompetence and resolution of paralysis followed the surgical intervention.

[A Case of Esophageal Cancer with Cervical Lymph Node Recurrence Six Years after Complete Response to Definitive Chemoradiotherapy].

Neoadjuvant chemotherapy plus surgery is recommended for clinical StageⅡ and Ⅲ esophageal cancer treatment by the JCOG9906. In contrast, definitive chemoradiotherapy(dCRT)is also a curative treatment. We encountered a case of recurrence in the cervical lymph nodes that was confirmed 6 years later, although thoracic esophageal cancer had completely disappeared following dCRT. Since there was no recurrence or metastasis in the primary lesion or other organs, we performed bilateral cervical lymph node dissection. There were 3 lymph node metastases among the dissected cervical lymph nodes pathologically. After the surgery, no relapses have occurred without the adjuvant chemotherapy.

[Laparoscopic Endoscopic Cooperative Surgery(LECS)for Duodenal Tumors].

We report 2 cases of superficial non-ampullary duodenal tumor resected using laparoscopic endoscopic cooperative surgery( LECS). A man in his5 0's underwent screening esophagogastroduodenoscopy. Endoscopy revealed a 0-Ⅱc lesion at the anal side of the papilla of Vater that measured 5 mm. We performed LECS, and pathologic examination revealed tubular adenoma with no tumor cellsat the edge of the specimen. A man in his 80's underwent screening esophagogastroduodenoscopy. Endoscopy revealed a 0-Ⅱc lesion at the posterior wall above the papilla of Vater that measured 10 mm. The biopsy showed a well-differentiated adenocarcinoma. We performed LECS, and the pathological examination revealed a tubular adenocarcinoma in the mucosal layer with no carcinoma cells at the edge of the specimen. As the treatment strategy for superficial duodenal tumors has not established yet, further accumulation of cases and investigation are necessary.

Current status of cancer immunotherapy for esophageal squamous cell carcinoma.

BACKGROUND: Immunotherapy has become a promising treatment strategy for cancer. Immune checkpoint blockade with anti-CTLA4 mAb and anti-PD-1 mAb has demonstrated clear evidence of objective responses including improved overall survival and tumor shrinkage, driving renewed enthusiasm for cancer immunotherapy in multiple cancer types including esophageal squamous cell carcinoma (ESCC). There are several clinical trials using anti-PD1 mAb for ESCC in early phases and the results are currently promising. RESULTS AND CONCLUSIONS: In this review, recent advances in cancer immunotherapy for ESCC are discussed with particular focus on immune checkpoint inhibitors and cancer vaccine.

Stromal VCAN expression as a potential prognostic biomarker for disease recurrence in stage II-III colon cancer.

To develop prognostic biomarkers that can discriminate stage II-III colorectal cancer patients with high risk of postoperative recurrence, we conducted a genome-wide screening of relapse-related genes utilizing multiple microarray cohorts. Among differentially expressed genes between tumor and nontumor, we identified eight candidate genes associated with relapse in two datasets of stage II-III patients (n = 94 and 145, respectively, P < 0.05). Using datasets of laser-microdissected samples and FACS-purified cell populations, the localization of candidate genes, including COL4A2, COL4A1, VCAN and SERPINE1, were found predominantly in cancer stroma rather than epithelial components. Among those relapse-related stromal genes, VCAN mRNA, specifically expressed in cancer-associated fibroblasts, was further validated to be a prognostic factor in two additional independent datasets, consisting of 453 (P = 0.0334) and 89 (P = 0.0041) stage II-III patients. Furthermore, in our large set of formalin-fixed paraffin-embedded cohort (n = 338), VCAN protein was detected exclusively in cancer stroma by immunohistochemistry, demonstrating a stepwise increase of stromal VCAN from normal tissues through stage 0 to stage IV tumors. Stromal VCAN protein was associated with shorter relapse-free survival (RFS) in stage II-III colon cancer, independent of other clinical factors by multivariate analysis (P = 0.004). Stratified analyses revealed that stromal VCAN was a strong prognostic indicator particularly in stage II colon cancer (P = 0.0029). In all five analyzed cohorts, the expression of VCAN, in transcript or protein levels, was associated with poor RFS in stage II-III patients. We conclude that VCAN is a promising biomarker to identify stage II-III patients at high risk of relapse who may benefit from intensive postoperative management.

[A Case of Port Site Recurrence after Laparoscopic Distal Gastrectomy for Advanced Gastric Cancer].

It has been suggested that port site recurrence is a potential complication after laparoscopic distal gastrectomy for gastric cancer, especially considering the increased number of laparoscopic surgeries being performed. We encountered a case of an 84-year-old man who was diagnosed with 2 port site recurrences at the navel and right hypochondrium after laparoscopic distal gastrectomy(D2). Pathological diagnosis for the original tumor was tub2, pT4a, pN1(1/38), M0, pStage III A, and HER2(0). As first-line chemotherapy with S-1 plus CDDP for the port site recurrence failed, second-line chemotherapy with ramucirumab plus paclitaxel(RAM plus PTX)was administered. Although RAM plus PTX therapy induced shrinkage of the port site recurrence, liver metastasis was detected as a new lesion. RAM mono-therapy maintained good QOL for 18 months after surgery.

[Risk Evaluation and Prognostic Prediction of Colorectal Cancer in Elderly Patients Over 80 Years of Age].

This study aimed to investigate risk factors and prognosis ofcolorectal cancer in patients over 80 years ofage. Surgical risk was evaluated by colorectal POSSUM(CR-POSSUM)and prognosis by Glasgow prognostic score(GPS). The analysis included 56 patients aged over 80 years with colorectal cancer during 2002-2012. Mean operation time, blood loss, and period ofhospitalization were 130 min, 111 mL, and 19.9 days, respectively. Postoperative complications occurred in 26 patients (46.4%; complications group). The 5-year overall survival rate for patients with complication scores above 2 was 51.1%, compared to 82.3% in a control group, and patients in the complication group also exhibited a poorer prognosis. CR-POS SUM scores were significantly higher in the complication group than in the control group in PS, OS, and PMR. Further analysis revealed that patients with GPS 0 or 1 had a significantly higher 5-year survival rate(84.9%)than those with GPS2(38.9%, p <0.05).

Combination of oligo-fractionated irradiation with nivolumab can induce immune modulation in gastric cancer.

BACKGROUND: Tumor-associated antigen (TAA)-specific CD8(+) T cells are essential for nivolumab therapy, and irradiation has been reported to have the potential to generate and activate TAA-specific CD8(+) T cells. However, mechanistic insights of T-cell response during combinatorial immunotherapy using radiotherapy and nivolumab are still largely unknown. METHODS: Twenty patients included in this study were registered in the CIRCUIT trial (ClinicalTrials.gov, NCT03453164). All patients had multiple distant metastases and were intolerance or had progressed after primary and secondary chemotherapy without any immune checkpoint inhibitor. In the CIRCUIT trial, eligible patients were treated with a total of 22.5 Gy/5 fractions/5 days of radiotherapy to the largest or symptomatic lesion prior to receiving nivolumab every 2 weeks. In these 20 patients, T-cell responses during the combinatorial immunotherapy were monitored longitudinally by high-dimensional flow cytometry-based, multiplexed major histocompatibility complex multimer analysis using a total of 46 TAAs and 10 virus epitopes, repertoire analysis of T-cell receptor ß-chain (TCRß), together with circulating tumor DNA analysis to evaluate tumor mutational burden (TMB). RESULTS: Although most TAA-specific CD8(+) T cells could be tracked longitudinally, several TAA-specific CD8(+) T cells were detected de novo after irradiation, but viral-specific CD8(+) T cells did not show obvious changes during treatment, indicating potential irradiation-driven antigen spreading. Irradiation was associated with phenotypical changes of TAA-specific CD8(+) T cells towards higher expression of killer cell lectin-like receptor subfamily G, member 1, human leukocyte antigen D-related antigen, T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain, CD160, and CD45RO together with lower expression of CD27 and CD127. Of importance, TAA-specific CD8(+) T cells in non-progressors frequently showed a phenotype of CD45RO(+)CD27(+)CD127(+) central memory T cells compared with those in progressors. TCRß clonality (inverted Pielou's evenness) increased and TCRß diversity (Pielou's evenness and Diversity Evenness score) decreased during treatment in progressors (p=0.029, p=0.029, p=0.012, respectively). TMB score was significantly lower in non-progressors after irradiation (p=0.023). CONCLUSION: Oligo-fractionated irradiation induces an immune-modulating effect with potential antigen spreading and the combination of radiotherapy and nivolumab may be effective in a subset of patients with gastric cancer.

Immunological Responses Associated With Neoadjuvant Therapy in the Tumor Microenvironment of Esophageal Squamous Cell Carcinoma.

BACKGROUND/AIM: Development of multidisciplinary therapies including immune checkpoint inhibitors for esophageal squamous cell carcinoma (ESCC) requires a clear understanding of immunological responses induced by chemotherapy with/without radiotherapy in the tumor microenvironment. PATIENTS AND METHODS: This is a retrospective analysis of paired pretreatment biopsy samples and surgically resected tumor samples of 49 patients who underwent radical surgery for ESCC with/without neoadjuvant therapy at Fukushima Medical University Hospital. The cohort included 30 patients treated with neoadjuvant chemotherapy (NAC), 11 treated with neoadjuvant chemoradiotherapy (NACRT), and eight who underwent surgery alone and did not receive neoadjuvant antitumor therapy. Chemotherapy included fluoropyrimidine- and platinum-based agents in all treated patients, and radiotherapy included 40 or 42 Gy administered in 20 or 21 fractions. Expression of CD8, human leukocyte antigen (HLA) class I-ABC, PD-L1, PD-L2, CEACAM-1, LSECtin, and p-STAT1, were determined using immunohistochemistry. RESULTS: The frequency of tumor-infiltrating CD8+ T cells was significantly increased by NAC (p<0.05), and the expression of HLA class I-ABC on tumor cells was significantly increased by NAC and NACRT (p<0.05). Furthermore, the ESCC cells expressed PD-L1, PD-L2, and CEACAM-1, whereas the expression of PD-L1 on ESCC cells was significantly correlated with the expression of p-STAT1 in ESCC cells (p<0.05). CONCLUSION: NAC and NACRT induced both positive and negative immunological responses in patients with ESCC. These results may be a part of basis for multidisciplinary therapy including immune checkpoint inhibitors for patients with advanced ESCC.

Phase I/II clinical trial of nivolumab in combination with oligo-fractionated irradiation for unresectable advanced or recurrent gastric cancer.

BACKGROUND: Although immune checkpoint inhibitors (ICI) targeting for PD-1 axis is a promising approach for advanced gastric cancer (GC) patients, the response rate is still limited. Induction of synergistic effect of irradiation with ICI targeting for the PD-1 axis can be an attractive strategy. The aim of this study was to assess the effect of the combination of irradiation with anti-PD-1 therapy for advanced GC. METHODS: We conducted a single-arm, phase I/II trial in GC patients treated with a combination of nivolumab and oligo-fractionated irradiation (22.5 Gy/5 fractions/5 days) (NCT03453164). Eligible patients (n = 40) had unresectable advanced or recurrent GC which progressed after primary and secondary chemotherapy with more than one lesion. The primary endpoint is the disease control rate (DCR) of non-irradiated target lesions and the secondary endpoints are the median survival time (MST), safety, and DCR of irradiated lesions. RESULTS: We observe that the DCR for the non-irradiated target as the abscopal effect is 22.5% (90% confidence interval (CI), 12.3-36.0), and the DCR for the irradiated lesion is 40.0% (90% CI, 26.9-54.2). The median survival time is 230 days (95% CI, 157-330), and grade 3 and higher adverse events (AEs) are observed in 16 patients (39 %) with no obvious additional AEs when adding irradiation. CONCLUSIONS: The present study suggests that the combination of nivolumab with oligo-fractionated irradiation has the potential to induce a promising anti-tumor effect for advanced GC.

Immunotherapy is a type of treatment that triggers the immune system to kill cancers. Combining immunotherapy with radiotherapy may enhance its effects. We evaluated this in a clinical trial in which we treated patients with advanced or recurrent cancers of the stomach (gastric cancer) with a combination of immunotherapy and radiotherapy. The combination was able to control disease in a subset of patients and was safe, with no obvious additional adverse effects when adding radiotherapy. The median survival time­at which point half of the patients treated are still alive­was 230 days. While these results are promising, larger, more rigorous studies are needed to determine whether this combination therapy is better than alternative approaches to treating advanced or recurrent gastric cancers.

Preoperative bacterial culture can predict severe pneumonia in patients receiving esophagectomy.

BACKGROUND: Postoperative pneumonia is one of the major complications after esophagectomy. The aim of this study was to determine whether bacterial cultures before esophagectomy could predict occurrence of postoperative pneumonia and help treatment strategies for postoperative pneumonia. METHODS: Sixty-nine patients who underwent subtotal esophagectomy at Fukushima Medical University Hospital between January 2017 and May 2021 were included in this study. We collected sputum, oral, and/or nasopharyngeal swabs for bacterial culture preoperatively from all patients and from those who were suspected of postoperative pulmonary infections. We compared cultured pathogenic bacteria obtained preoperatively and postoperatively from patients who developed postoperative pneumonia, and investigated their association with incidence of postoperative pneumonia. RESULTS: Postoperative pneumonia occurred in 22 of 69 patients (31%), including 13 cases of severe pneumonia with a Clavien-Dindo classification of grade IIIa or higher. Multivariate analysis revealed that longer operative duration (for 30 minutes increase;odds ratio 1.27, 95% CI 1.01-1.51, p=0.039) and positivity for preoperative bacterial culture (odds ratio 5.03, 95% CI 1.31-19.2, p=0.018) were independent risk factors for severe postoperative pneumonia, but not for all incidences of postoperative pneumonia. Of note, in only 5 of the 22 patients with pneumonia, the same pathogenic species were detected preoperatively and after the onset of pneumonia. CONCLUSIONS: Our results imply that preoperative bacterial culture may be useful to predict severe postoperative pneumonia. However, it may not be useful in determining pathogenic bacteria responsible for postoperative pneumonia.

Clinical outcomes of laparoscopic and endoscopic cooperative surgery for gastric gastrointestinal stromal tumor.

BACKGROUND: Laparoscopic and endoscopic cooperative surgery (LECS) is a well-recognized surgical procedure for gastric gastrointestinal stromal tumor (GIST). In this report, we describe the clinical outcomes of LECS procedures for gastric GIST in our institution. METHODS: We performed LECS procedures, including classical LECS, inverted LECS, closed LECS, and combination of laparoscopic and endoscopic approaches to neoplasia with non-exposure technique (CLEAN-NET), in 40 gastric intraluminal and intramural type GIST patients, whose tumors were ≤ 50 mm in diameter, between September 2012 and December 2020. The patient background, surgical outcomes, postoperative morbidity and mortality, as well as the tumors' clinicopathological characteristics were analyzed retrospectively. RESULTS: Pathological findings showed that most patients had a low or very low risk of tumor recurrence, while one patient had a high risk according to the modified-Fletcher's classification. The median length of postoperative hospital stay was 7 days. Only one patient had severe postoperative grade III complications according to the Clavien-Dindo (C-D) classification, after closed LECS, but was treated successfully with endoscopic hemostasis for postoperative hemorrhage. The remaining patients treated with LECS did not have severe complications. During the follow-up period (median, 31 months), all patients were disease-free, with no tumor recurrence or metastases. CONCLUSION: LECS is a safe surgical procedure for gastric intraluminal and intramural type GIST ≤ 50 mm in diameter, with good clinical outcomes.

Ectopic expression of MECA-79 as a novel prognostic indicator in gastric cancer.

The aim of this study was to clarify the clinical implications of a unique carbohydrate determinant, MECA-79, in gastric cancer specimens and cells. Immunohistochemical analysis showed that 62 of 225 (27.6%) cases were defined as positive for MECA-79. MECA-79 expression was correlated with depth of invasion, venous invasion, TNM stage, and distant metastasis. In survival analyses, patients with MECA-79 expression had worse prognosis by the log-rank test. Multivariate analysis of the Cox proportional hazard model showed that MECA-79 expression was an independent factor of a worse cancer-specific survival. Among 11 gastric cancer cells, MECA-79 was observed in only MKN7 cells, which also expressed GlcNAc6ST-2 transcript. A knockdown of GlcNAc6ST-2 in MKN7 cells showed a markedly reduced expression of MECA-79, suggesting that GlcNAc-sulfation of MECA-79 is mainly synthesized by GlcNAc6ST-2. Furthermore, real-time RT-PCR analysis revealed that GlcNAc6ST-2 was significantly increased in cancer tissues compared with paired normal mucosa. In conclusion, the expression of MECA-79 could be a useful marker for the prognosis of gastric cancer. Our results might also provide novel perspectives on the biology of MECA-79 and GlcNAc6ST-2 in cancer progression and metastasis.