Totally laparoscopic versus laparoscopy-assisted distal gastrectomy: the KLASS-07, a randomized controlled trial.

BACKGROUNDS: Strong evidence is lacking as no confirmatory randomized controlled trials (RCTs) have compared the efficacy of totally laparoscopic distal gastrectomy (TLDG) with laparoscopy-assisted distal gastrectomy (LADG). We performed an RCT to confirm if TLDG is different from LADG. METHODS: The KLASS-07 trial is a multicentre, open-label, parallel-group, phase III, RCT of 442 patients with clinical stage I gastric cancer. Patients were enrolled from 21 cancer care centers in South Korea between January 2018 and September 2020 and randomized to undergo TLDG or LADG using blocked randomization with a 1:1 allocation ratio, stratified by the participating investigators. Patients were treated through R0 resections by TLDG or LADG as the full analysis set of the KLASS-07 trial. The primary endpoint was morbidity within postoperative day 30, and the secondary endpoint was QoL for 1 year. This trial is registered at ClinicalTrials.gov (NCT NCT03393182). RESULTS: 442 patients were randomized (222 to TLDG, 220 to LADG), and 422 patients were included in the pure analysis (213 and 209, respectively). The overall complication rate did not differ between the two groups (TLDG vs. LADG: 12.2% vs. 17.2%). However, TLDG provided less postoperative ileus and pulmonary complications than LADG (0.9% vs. 5.7%, P= 0.006; and 0.5% vs. 4.3%, P= 0.035, respectively). The QoL was better after TLDG than after LADG regarding emotional functioning at 6 months, pain at 3 months, anxiety at 3 and 6 months, and body image at 3 and 6 months (all P< 0.05). However, these QoL differences were resolved at 1 year. CONCLUSIONS: The KLASS-07 trial confirmed that TLDG is not different from LADG in terms of postoperative complication but has advantages to reduce ileus and pulmonary complications. TLDG can be a good option to offer better QoL in terms of pain, body image, emotion, and anxiety at 3-6 months.

Comparison between the mesenteric fixation method (MEFIX) and conventional methods at preventing the occurrence of Petersen's hernia: a study protocol for a multicenter randomized controlled trial.

BACKGROUND: Petersen's hernia, which occurs after Billroth-II (B-II) or Roux-en-Y (REY) anastomosis, can be reduced by defect closure. This study aims to compare the incidence of bowel obstruction above Clavien-Dindo classification grade III due to Petersen's hernia between the mesenteric fixation method and the conventional methods after laparoscopic or robotic gastrectomy. METHODS: This study was designed as prospective, single-blind, non-inferiority randomized controlled multicenter trial in Korea. Patients with histologically diagnosed gastric cancer of clinical stages I, II, or III who underwent B-II or REY anastomosis after laparoscopic or robotic gastrectomy are enrolled in this study. Participants who meet the inclusion criteria are randomly assigned to two groups: a CLOSURE group that underwent conventional Petersen's defect closure method and a MEFIX group that underwent the mesenteric fixation method. The primary endpoint is the number of patients who underwent surgery for bowel obstruction caused by Petersen's hernia within 3 years after laparoscopic or robotic gastrectomy. DISCUSSION: This trial is expected to provide high-level evidence showing that the MEFIX method can quickly and easily close Petersen's defect without increased postoperative complications compared to the conventional method. TRIAL REGISTRATION: ClinicalTrials.gov NCT05105360. Registered on November 3, 2021.

Exploring ideal operative time for best outcomes in gastric cancer surgery: A multi-institutional study based on KLASS-07 database.

Objective: While a rushed operation can omit essential procedures, prolonged operative time results in higher morbidity. Nevertheless, the optimal operative time range remains uncertain. This study aimed to estimate the ideal operative time range and evaluate its applicability in laparoscopic cancer surgery. Methods: A prospectively collected multicenter database of 397 patients who underwent laparoscopic distal gastrectomy were retrospectively reviewed. The ideal operative time range was statistically calculated by separately analyzing the operative time of uneventful surgeries. Finally, intraoperative and postoperative outcomes were compared among the shorter, ideal, and longer operative time groups. Results: The statistically calculated ideal operative time was 135.4-165.4 min. The longer operative time (LOT) group had a lower rate of uneventful, perfect surgery than the ideal or shorter operative time (IOT/SOT) group (2.8% vs. 8.8% and 2.2% vs. 13.4%, all P<0.05). Longer operative time increased bleeding, postoperative morbidities, and delayed diet and discharge (all P<0.05). Particularly, an uneventful, perfect surgery could not be achieved when the operative time exceeded 240 min. Regardless of ideal time range, SOT group achieved the highest percentage of uneventful surgery (13.4%), which was possible by surgeon's ability to retrieve a higher number of lymph nodes and perform ≥150 gastrectomies annually. Conclusions: Operative time longer than the ideal time range (especially ≥240 min) should be avoided. If the essential operative procedure were faithfully conducted without compromising oncological safety, an operative time shorter than the ideal range leaded to a better prognosis. Efforts to minimize operative time should be attempted with sufficient surgical experience.

Detection of Circulating Gastrointestinal Cancer Cells in Conditionally Reprogrammed Cell Culture.

BACKGROUND/AIM: The aim of this study was to detect circulating tumor cells (CTC) in the peripheral blood of gastrointestinal cancer patients using conditionally reprogrammed cell (CRC) culture. MATERIALS AND METHODS: We confirmed the sensitivity of the CRC culture method. Five ml of blood were obtained from 81 cancer patients (56 colorectal and 25 gastric). The collected mononuclear cells were cultured for 4 weeks in the CRC condition. Finally, cultured cells were characterized by RT-PCR for the expression of hTERT and MAGE A1-6 mRNA. RESULTS: The CRC method had a CTC detection limit of 6 cells for gastric cancer cells. After culture of 81 blood specimens, 38 formed visible cells, including 5 colonies. Among the 38 cells, 13 were hTERT positive and 4 were MAGE A1-6 positive. The final CTC detection rate was 16.0%. CONCLUSION: The CRC culture may potentially be used to evaluate the metastatic cancer cells in the circulation.

Melanoma antigen-encoding gene family member A1-6 and hTERT in the detection of circulating tumor cells following CD45- depletion and RNA extraction.

A total of 76 blood samples from patients without malignant disease and 107 blood samples from patients with malignant disease were investigated for the presence of circulating tumor cells (CTCs). To detect CTCs, hematopoietic cells were removed from the blood samples and different RNA extraction methods were used to amplify the melanoma antigen-encoding gene family member A1-family member A6 (MAGE A1-6) and the human telomerase reverse transcriptase (hTERT) gene as potential CTC markers. Comparison between four methods for extracting RNA from the blood was performed. The samples were enriched by cluster of differentiation 45 (CD45) antibody capturing, and the reverse transcription-quantitative polymerase chain reaction was used to amplify the MAGE A1-6 and hTERT genes. MAGE A1-6 and hTERT gene expression levels were also evaluated in 14 cancer cell lines, and the MAGE A1-6 and hTERT expression levels were 85.7 and 100%, respectively. The RNeasy method demonstrated the most sensitivity in the SNU1 cells mixed with blood, although the differences between methods was non-significant. The positive expression levels of MAGE A1-6 and hTERT was 11.8% in the control group and 58.9% in those with malignant disease. In the 70 patients with colorectal cancer, positive expression levels of MAGE A1-6 or hTERT were significantly higher in stages T3 and T4 compared with in stages T1 and T2. The CTC detection method involving CD45 antibody capture, RNA extraction and MAGE A1-6 and hTERT reverse transcription resulted in good rates of sensitivity and specificity. Thus, the present study concluded that MAGE A1-6 and hTERT genes may be potential and practical markers for CTCs in a clinical setting.

Effect of Acupuncture on Postoperative Ileus after Distal Gastrectomy for Gastric Cancer.

PURPOSE: Acupuncture has recently been accepted as a treatment option for managing postoperative ileus (POI) and various functional gastrointestinal disorders. Therefore, we conducted a prospective randomized study to evaluate the effect of acupuncture on POI and other surgical outcomes in patients who underwent gastric surgery. MATERIALS AND METHODS: Thirty-six patients who underwent distal gastrectomy for gastric cancer from March to December 2015 were randomly assigned to acupuncture or non-acupuncture (NA) groups at 1:1 ratio. The acupuncture treatment was administered treatment once daily for 5 consecutive days starting at postoperative day 1. The primary outcome measure was the number of remnant sitz markers in the small intestine on abdominal radiograph. The secondary outcome measure was the surgical outcome, including the times to first flatus, first defecation, start of water intake, and start of soft diet, as well as length of hospital stay and laboratory findings. RESULTS: The acupuncture group had significantly fewer remnant sitz markers in the small intestine on postoperative days 3 and 5 compared to those in the NA group. A significant difference was observed in the numbers of remnant sitz markers in the small intestine with respect to group differences by time (P<0.0001). The acupuncture group showed relatively better surgical outcomes than those in the NA group, but the differences were not statistically significant. CONCLUSIONS: In this clinical trial, acupuncture promoted the passage of sitz markers, which may reflect the possibility of reducing POI after distal gastrectomy.

Validation of the 7th AJCC/UICC staging system for gastric cancer and a proposal for a new TNM system based on a prognostic score: a retrospective multicenter study.

PURPOSE: We validate the 7th American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) staging system for gastric cancer and propose a new staging system that reflects the prognostic significances of each of T and N category. METHODS: Data from 5,957 patients who underwent curative gastrectomies from 2000 to 2007 at 4 university hospitals in Daegu Metropolitan city in Korea were analyzed for the validation of the 7th AJCC/UICC staging system for gastric cancer. The hazard ratios of the respective T and N categories were estimated and converted to weightings and summated to make prognostic score (P-score). Homogeneity and stage grouping were determined according to the P-scores. RESULTS: In the 7th AJCC/UICC staging system for gastric cancer, poor discrimination was noted between stages IIB and IIIA (P = 0.152). In addition, heterogeneity in stage IIB (P = 0.021) and a small gap in 5-year survival rates (1.7%) between stages IA and IB were noted. A new proposed staging system was generated on the basis of P-scores and demonstrated more discrimination between stages and more homogeneity within stages. The new staging system reflects the different prognostic impacts of N3a and N3b. CONCLUSION: Several controversial issues of the 7th AJCC/UICC staging system for gastric cancer were reconfirmed in the present analysis. The TNM system based on P-score appears to be more scientifically accurate than the 7th AJCC/UICC staging system for gastric cancer.

Prognostic significance of CEA expression by RT-PCR in peritoneal wash from patients with gastric cancer: result of a 5-year follow-up after curative resection.

OBJECTIVE: Peritoneal recurrence is the most common cause of death after surgery for gastric cancer. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis has been used to detect free cancer cells in peritoneal wash during surgery. This study was conducted to evaluate the prognostic significance of carcinoembrionic antigen (CEA) mRNA detected by RT-PCR in peritoneal wash from patients with gastric cancer after curative resection through a 5-year follow-up. MATERIALS AND METHODS: Peritoneal wash were obtained from 117 patients who underwent curative surgery for gastric cancer. The association between the CEA RT-PCR results, clinicopathological factors, and factors affecting gastric cancer recurrence were evaluated. RESULTS: Among the 117 cases, 38 (32.5%) revealed positive CEA expression. Patients with positive CEA expression showed a higher rate of peritoneal recurrence than those with negative CEA expression (p = 0.047). Depth of invasion, lymph node metastasis, TNM stage, and CEA expression were factors affecting recurrence. CEA expression and depth of invasion were significant prognostic factors in a multivariate analysis, and CEA expression was the most important prognostic factor for recurrence in patients who had undergone curative resection for gastric cancer (hazard ratio: 2.747, p = 0.046). CONCLUSIONS: CEA expression in the peritoneal wash was significantly associated with peritoneal recurrence and was the most important prognostic factor for gastric cancer recurrence after curative resection.

Effect of Acupuncture on Reducing Duration of Postoperative Ileus After Gastrectomy in Patients with Gastric Cancer: A Pilot Study Using Sitz Marker.

OBJECTIVES: Postoperative ileus (POI) is a common problem after abdominal surgery. Acupuncture is being accepted as an option for reducing POI and managing various functional gastrointestinal disorders. Therefore, this pilot study was conducted to evaluate the effect of acupuncture on reducing duration of POI and other surgical outcomes in patients who underwent gastric surgery. DESIGN: A prospective, randomized, controlled pilot study was conducted on patients who underwent gastric cancer surgery from January 2013 to December 2013. Ten patients were randomly assigned into the acupuncture (A) or nonacupuncture (NA) groups at a 1:1 ratio. INTERVENTIONS: The acupuncture treatment was performed by Korean traditional medicine doctors (KMDs). The style of acupuncture was Korean. In the A group, acupuncture treatment was given once daily for 5 consecutive days starting on postoperative day 1. Each patient received acupuncture at 16 acupoints based on expert consensus provided by qualified and experienced KMDs. No acupuncture treatment was performed in the NA group. OUTCOME MEASURES: The primary outcome measure was the number of remnant Sitz markers in the small intestine on abdominal radiography. Secondary outcome measures were time to first flatus, start of sips water, start of soft diet, hospital stay, and laboratory findings. RESULTS: The A group had significantly fewer remnant Sitz markers in the small intestine on postoperative days 3 and 5 compared with those in the NA group (p = 0.025 and 0.005). A significant difference was observed in the numbers of remnant Sitz marker in the small intestine with respect to time difference by group (p = 0.019). The A group showed relatively better surgical outcomes, but without statistical significance. CONCLUSIONS: Although further studies are warranted, acupuncture may reduce duration of POI after gastric surgery and could be a potential factor in enhanced recovery after surgery protocols.

Role of genetic detection in peritoneal washes with gastric carcinoma: The past, present and future.

The most frequent cause of treatment failure following surgery for gastric cancer is peritoneal dissemination, mainly caused by the seeding of free cancer cells from the primary gastric cancer, which is the most common type of spread. Unfortunately, there is no standard modality of intraperitoneal free cancer cells detection to predict peritoneal metastasis until now. We reviewed English literature in PubMed was done using the MeSH terms for gastric cancer, peritoneal wash, and reverse transcriptase polymerase chain reaction. All the articles were reviewed and core information was tabulated for reference. After a comprehensive review of all articles, the data was evaluated by clinical implication and predictive value of each marker for peritoneal recurrence. There are still many limitations to overcome before the genetic diagnosis for free cancer cells detection can be considered as routine assay. To make it a reliable diagnostic tool for detecting free cancer cells, the process and method of genetic detection with peritoneal washes should be standardized, and the development of simple diagnostic devices and easily available kits are necessary. Herein, we reviewed the past, present and future perspectives of the peritoneal lavage for the detection of intraperitoneal free cancer cells in patients with gastric cancer.

Comparison of short-term outcomes and acute inflammatory response between laparoscopy-assisted and totally laparoscopic distal gastrectomy for early gastric cancer.

PURPOSE: Laparoscopic gastrectomy is widely used to treat early gastric cancer. The advantages of totally laparoscopic distal gastrectomy (TLDG) are unproven, and some concerns remain regarding the early surgical outcomes due to its technical difficulty. We compared the early surgical outcomes and acute inflammatory response between patients undergoing TLDG and laparoscopy-assisted distal gastrectomy (LADG) for treatment of early gastric cancer. METHODS: We performed a retrospective study on 212 consecutive patients who underwent laparoscopic distal gastrectomy for gastric cancer between January 2008 and June 2014. A total of 179 LADG cases and 33 TLDG cases were included. After age, sex, body mass index, and American Society of Anesthesiologists physical status score were matched using propensity score matching (PSM), we compared the short-term surgical outcomes between the LADG and TLDG groups. RESULTS: The TLDG group had a shorter hospital stay (9.5 days vs. 11.0 days, P = 0.046) and less blood loss (116.6 mL vs. 141.5 mL, P = 0.031) than those in the LADG group. There were no differences in the preoperative WBC count and CRP level and the other clinical data between the two groups after PSM. Postoperative WBC count, serum CRP level, and decrease rate of WBC count in the TLDG group were significantly lower than those in the LADG group. CONCLUSION: The short-term outcomes of TLDG revealed better than that of LADG in this study. Therefore, TLDG is one of the safe and feasible procedure for the treatment of early gastric cancer.

Prognostic Factors of Patients with Gastric Gastrointestinal Stromal Tumor after Curative Resection: A Retrospective Analysis of 406 Consecutive Cases in a Multicenter Study.

BACKGROUND/PURPOSE: Gastric gastrointestinal stromal tumors (GISTs) have a highly variable clinical course, and recurrent disease sometimes develops despite curative surgery. This study was undertaken to investigate the surgical role in treating gastric GISTs and evaluate the clinicopathological features of a large series of patients who underwent curative resection for gastric GISTs to clarify which features were independent prognostic factors. METHODS: The clinicopathological data of 406 patients with gastric GISTs who underwent curative resection at 4 university hospitals in Daegu, South Korea, from March 1998 to March 2012 were reviewed. All cases were confirmed as gastric GISTs by immunohistochemical staining, in which CD117 or CD34 was positive. Clinical follow-up was performed periodically, and disease-free survival rates were retrospectively investigated using the medical records. RESULTS: The mean follow-up period was 42.9 months (range: 2-166). There were 11 recurrent patients (2.7%). Due to the small number of recurrences, age, sex and location were controlled using propensity score matching before performing any statistical analysis. Tumor size, mitotic count, NIH classification, and cellularity were judged to be independent prognostic factors for recurrence by univariate analysis. In a multivariate analysis, tumor size and mitotic count were significantly and independently related to recurrence, and tumor size was determined to be the most important prognostic factor for recurrence after curative resection (hazard ratio: 1.204; p < 0.01). CONCLUSIONS: The results of this multicenter study demonstrate that disease-free survival rates are good. Tumor size was disclosed as the most important factor for recurrence in gastric GIST patients who underwent radical resection.

Gastrointestinal stromal tumors (GISTs) of the stomach: a multicenter, retrospective study of curatively resected gastric GISTs.

PURPOSE: The standard treatment for primary localized gastric gastrointestinal stromal tumor (GIST) is surgical resection. The clinical behavior of gastric GIST after surgical resection is extremely variable. We conducted a multicenter, retrospective study of gastric GISTs patients who underwent curative surgical resection to evaluate clinical features and the prognosis of surgically treated gastric GISTs. METHODS: We performed a retrospective study on 406 consecutive patients who underwent curative resections for localized gastric GIST at four university hospitals in Daegu, Korea, between March 1998 and March 2012. The retrospectively collected medical records were reviewed with respect to clinical parameters including age, gender, tumor location, surgical approach, and recurrence. RESULTS: There were 406 patients: 157 males (38.7%) and 249 females (61.3%), with a mean age of 60.8 ± 10.8 (standard deviation) years. The mean tumor size was 4.9 cm (range, 0.3-29 cm). Curative surgical resection was performed in all patients without tumor rupture or spillage. Laparoscopic wedge resections were performed in 156 patients (38.4%) and open resections in 250 patients (61.6%). The tumor size of the laparoscopic wedge resection group was smaller than that of open resection group (3.45 cm vs. 5.46 cm; P < 0.001). There were 11 recurrent cases (2.7%). No recurrence was observed in patients who underwent laparoscopic wedge resections. CONCLUSION: Gastric GISTs had a low recurrence rate after curative resection in our series. Laparoscopic gastric wedge resection is feasible for treating gastric GISTs in selected patients.

Prognostic value of genetic detection using CEA and MAGE in peritoneal washes with gastric carcinoma after curative resection: result of a 3-year follow-up.

Peritoneal metastasis is the most frequent cause of death in patients with gastric cancer. Reverse transcriptase-polymerase chain reaction (RT-PCR) assay of peritoneal washes has been used to predict peritoneal metastasis of gastric carcinoma. We applied carcinoembryonic antigen (CEA) and melanoma-associated gene (MAGE) RT-PCR for the detection of peritoneal metastasis of gastric carcinoma after curative surgery and evaluated its clinical significance. Peritoneal washes were obtained from 117 patients with gastric carcinoma. MAGE A1-A6 and CEA RT-PCR were performed, and the results were evaluated according to their clinicopathologic characteristics. Three-year follow-up clinical studies were periodically performed, and disease-free survival rates were retrospectively investigated using the medical records. Among 117 peritoneal fluids, 11 cases (9.4%) revealed MAGE expression and 38 cases (32.5%) revealed CEA expression. When focusing on recurrence rates, RT-PCR-positive had much higher recurrence rates than RT-PCR-negative cases (32.5% vs 5.2%, P < 0.01). Univariate analysis revealed that depth of invasion, lymph node metastasis, tumor node metastasis (TNM) stage, Lauren classification, and MAGE and CEA expressions were independent prognostic factors for recurrence. In a multivariate analysis, MAGE expression and TNM stage were significantly and independently related to recurrence in patients who underwent curative resection. MAGE expression was determined to be the most important prognostic factor for recurrence (hazard ratio: 12.487, P < 0.01). It is feasible to identify free cancer cells in peritoneal lavage by using a MAGE A1-A6 and CEA RT-PCR. MAGE RT-PCR results disclosed significant associations with peritoneal recurrence and proved to be the most important factor for the recurrence rate in patients with gastric carcinoma who had undergone radical resection.

Peutz-Jeghers syndrome with germline mutation of STK11.

Peutz-Jeghers syndrome (PJS), also known as periorificial lentiginosis, is a rare autosomal dominant inherited disease with an incidence of 1/200,000 live-borns. Mutations in the serine-threonine kinase 11 (STK11) gene are considered the major cause of PJS. The most frequent complication at young age is recurrent intussusception due to multiple hamartomatous polyps, primarily in the small intestine. Although extremely rare, the small bowel should be fully examined to be certain additional intussusceptions are not present. Herein, we report on a case of PJS with germline mutation of STK11 in a 12-year-old young girl who presented as a rare case of two small intestinal intussusceptions and review the literature.

Clinical significance of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 gene polymorphisms in patients with gastrointestinal stromal tumors.

AIM: The vascular endothelial growth factor (VEGF) or its family might play role in tumor-related angiogenesis in gastrointestinal stromal tumors (GIST), thereby affecting the prognosis. Accordingly, the present study analyzed the impact of VEGF and VEGF receptor-2 (VEGFR-2) gene polymorphisms on the prognosis for GIST patients. METHODS: In all, 213 consecutive patients with GIST from five medical centers were enrolled in the present study. The genomic DNA was extracted from paraffin-embedded tumor tissue, and four VEGF (-2578C/A, -1498C/T, -634G/C, and +936C/T) and one VEGFR-2 (+1416A/T) gene polymorphisms were determined using a Sequenom MassARRAY system. RESULTS: With a median follow up of 18.4 months, the estimated 5-year relapse-free survival and overall survival rates were 70 and 87%, respectively. In a multivariate analysis including age, sex, primary site of disease, pathology and risk stratification, no significant association was observed between the polymorphism of the VEGF and VEGFR-2 genes and survival. CONCLUSION: None of the five VEGF and VEGFR-2 gene polymorphisms investigated in this study was found to be an independent prognostic marker for Korean patients with surgically resected GIST. However, further studies on a larger scale are warranted to clarify the role of VEGF and VEGFR gene polymorphisms as a prognostic biomarker for GIST patients.

Gastric cancer detection using gastric juice pepsinogen and melanoma-associated gene RNA.

OBJECTIVES: To develop a new method for gastric cancer detection with gastric juice using melanoma-associated gene (MAGE) RNA and pepsinogen (PG). METHODS: In total, 183 gastric juice and paired serum specimens were obtained from 134 patients with gastric cancer and 49 healthy individuals. The gastric juice specimens were analyzed with MAGE A1 to A6 nested reverse transcription-polymerase chain reaction. The serum and gastric juice PG were measured with a PG I and II immunoassay. RESULTS: The gastric juice PG I and PG I/II ratios were more accurate than those of serum. The combination test using the gastric PG I/II ratio and MAGE was the most accurate, with a sensitivity of 77.6% and a specificity of 87.8%. The sensitivity was 78.8% for stage I gastric cancer and not influenced by cancer location or pathologic type. CONCLUSIONS: The combination test is potentially an additional tool for gastric cancer detection.

γδ T cells are increased in the peripheral blood of patients with gastric cancer.

BACKGROUND: γδ T cells are implicated in immunoregulation. However, little is known about the characteristics of γδ T cells in gastric cancer. In this study, we assessed the incidence of γδ T cells and lymphocyte subsets in the peripheral blood of gastric cancer patients. METHODS: We enrolled 48 patients and 49 healthy controls. The γδ T cells, lymphocyte subsets were analyzed with flow cytometry. RESULTS: The mean percentage of γδ T cells in patients with gastric cancer was 5.0±3.4% and for controls 2.3±1.6%. Twenty (41.7%) of the 48 patients with gastric cancer had a high percentage (more than 5%) of peripheral blood γδ T cells, while 4 (8.2%) of the 49 controls did. The percentage of CD3⁺ T cells were elevated in gastric cancer compared to controls (P=0.007). The CD4/CD8 ratio increased in gastric cancer (P=0.311). The percentage of CD3⁺CD4⁻CD8⁻ T cells increased in gastric cancer compared to controls (P=0.004). CONCLUSION: The proportion of γδ T cells in the peripheral blood of gastric cancer patients was significantly higher in comparison to that in the healthy controls. Our findings suggest that increased proportion of peripheral γδ T cells may explain anti-tumor immunity against gastric cancer partly.

Composite neuroendocrine carcinoma with adenocarcinoma of the stomach misdiagnosed as a giant submucosal tumor.

A composite glandular/exocrine-endocrine carcinoma of the gastrointestinal tract is characterized by the co-existence of two adjacent, but histologically-distinct tumors in an organ. Composite glandular/exocrine-endocrine carcinomas are a special type of tumor comprised of common adenocarcinomas and neuroendocrine components that account for at least one-third of the entire tumor area. Composite tumors have been reported in a range of organs, but are relatively rare in the stomach. We report a case of a composite neuroendocrine carcinoma with an adenocarcinoma of the stomach (mixed exocrine-endocrine carcinoma), which was misdiagnosed as a giant submucosal tumor preoperatively based on esophagogastroduodenoscopy and a contrast-enhanced axial computed tomographic scan.

Role of F-fluoro-2-deoxyglucose Positron Emission Tomography in Gastric GIST: Predicting Malignant Potential Pre-operatively.

PURPOSE: It is difficult to obtain biopsies from gastrointestinal stromal tumors (GISTs) prior to surgery because GISTs are submucoal tumors, despite being the most common nonepithelial neoplasms of the gastrointestinal tract. Unlike anatomic imaging techniques, PET-CT, which is a molecular imaging tool, can be a useful technique for assessing tumor activity and predicting the malignant potential of certain tumors. Thus, we aimed to evaluate the usefulness of PET-CT as a pre-operative prognostic factor for GISTs by analyzing the correlation between the existing post-operative prognostic factors and the maximum SUV uptake (SUVmax) of pre-operative 18F-fluoro-2-deoxyglucose (FDG) PET-CT. MATERIALS AND METHODS: The study was conducted on 26 patients who were diagnosed with gastric GISTs and underwent surgery after being examined with pre-operative FDG PET-CT. An analysis of the correlation bewteen (i) NIH risk classfication and the Ki-67 proliferation index, which are post-operative prognostic factors, and (ii) the SUVmax of PET-CT, which is a pre-operative prognostic factor, was performed. RESULTS: There were significant correlations between (i) SUVmax and (ii) Ki-67 index, tumor size, mitotic count, and NIH risk group (r=0.854, 0.888, 0.791, and 0.756, respectively). The optimal cut-off value for SUVmax was 3.94 between "low-risk malignancy" and "high-risk malignancy" groups. The sensitivity and specificity of SUVmax for predicting the risk of malignancy were 85.7% and 94.7%, respectively. CONCLUSIONS: The SUVmax of PET-CT is associated with Ki-67 index, tumor size, mitotic count, and NIH classification. Therefore, it is believed that PET-CT is a relatively safe, non-invasive diagnostic tool for assessing malignant potential pre-operatively.