Efficacy of Hyperthermic Pressurized Intraperitoneal Aerosol Chemotherapy in an In Vitro Model Using a Human Gastric Cancer AGS Cell Line and an Abdominal Cavity Model.

PURPOSE: Peritoneal carcinomatosis (PC) presents a major challenge in the treatment of late-stage, solid tumors, with traditional therapies limited by poor drug penetration. We evaluated a novel hyperthermic pressurized intraperitoneal aerosol chemotherapy (HPIPAC) system using a human abdominal cavity model for its efficacy against AGS gastric cancer cells. MATERIALS AND METHODS: A model simulating the human abdominal cavity and AGS gastric cancer cell line cultured dishes were used to assess the efficacy of the HPIPAC system. Cell viability was measured to evaluate the impact of HPIPAC under 6 different conditions: heat alone, PIPAC with paclitaxel (PTX), PTX alone, normal saline (NS) alone, heat with NS, and HPIPAC with PTX. RESULTS: Results showed a significant reduction in cell viability with HPIPAC combined with PTX, indicating enhanced cytotoxic effects. Immediately after treatment, the average cell viability was 66.6%, which decreased to 49.2% after 48 hours and to a further 19.6% after 120 hours of incubation, demonstrating the sustained efficacy of the treatment. In contrast, control groups exhibited a recovery in cell viability; heat alone showed cell viability increasing from 90.8% to 94.4%, PIPAC with PTX from 82.7% to 89.7%, PTX only from 73.3% to 74.8%, NS only from 90.9% to 98.3%, and heat with NS from 74.4% to 84.7%. CONCLUSIONS: The HPIPAC system with PTX exhibits a promising approach in the treatment of PC in gastric cancer, significantly reducing cell viability. Despite certain limitations, this study highlights the system's potential to enhance treatment outcomes. Future efforts should focus on refining HPIPAC and validating its effectiveness in clinical settings.

MUC16 as a serum-based prognostic indicator of prometastatic gastric cancer.

Metastatic gastric cancer (GC) presents significant clinical challenges due to its poor prognosis and limited treatment options. To address this, we conducted a targeted protein biomarker discovery study to identify markers predictive of metastasis in advanced GC (AGC). Serum samples from 176 AGC patients (T stage 3 or higher) were analyzed using the Olink Proteomics Target panels. Patients were retrospectively categorized into nonmetastatic, metastatic, and recurrence groups, and differential protein expression was assessed. Machine learning and gene set enrichment analysis (GSEA) methods were applied to discover biomarkers and predict prognosis. Four proteins (MUC16, CAIX, 5'-NT, and CD8A) were significantly elevated in metastatic GC patients compared to the control group. Additionally, GSEA indicated that the response to interleukin-4 and hypoxia-related pathways were enriched in metastatic patients. Random forest classification and decision-tree modeling showed that MUC16 could be a predictive marker for metastasis in GC patients. Additionally, ELISA validation confirmed elevated MUC16 levels in metastatic patients. Notably, high MUC16 levels were independently associated with metastatic progression in T3 or higher GC. These findings suggest the potential of MUC16 as a clinically relevant biomarker for identifying GC patients at high risk of metastasis.

Clinical outcomes of neoadjuvant chemoradiotherapy followed by total mesorectal excision in locally advanced rectal cancer with mesorectal fascia involvement.

PURPOSE: For the treatment of locally advanced rectal cancer (LARC), research on primary lesions with mesorectal fascia (MRF) involvement is lacking. This study analyzed the clinical outcomes and efficacy of dose-escalated neoadjuvant concurrent chemoradiotherapy (NCRT) to patients with LARC involving MRF. MATERIALS AND METHODS: We retrospectively reviewed 301 patients who were diagnosed with LARC involving MRF and underwent NCRT followed by total mesorectal excision (TME). Patients who received radiotherapy (RT) doses of ≤50.4 Gy were defined as the non-boost group, while ≥54.0 Gy as the boost group. Pathological tumor response and survival outcomes, including intrapelvic recurrence-free survival (IPRFS), distant metastases-free survival (DMFS) and overall survival (OS), were analyzed. RESULTS: A total of 269 patients (89.4%) achieved a negative pathological circumferential resection margin and 104 (34.6%) had good pathological tumor regression grades. With a median follow-up of 32.4 months, IPRFS, DMFS, and OS rates at 5-years were 88.6%, 78.0%, and 91.2%, respectively. In the subgroup analysis by RT dose, the boost group included more advanced clinical stages of patients. For the non-boost group and boost group, 5-year IPRFS rates were 90.3% and 87.0% (p = 0.242), 5-year DMFS rates were 82.0% and 71.3% (p = 0.105), and 5-year OS rates were 93.0% and 80.6% (p = 0.439), respectively. Treatment related toxicity was comparable between the two groups (p = 0.211). CONCLUSION: Although this retrospective study failed to confirm the efficacy of dose-escalated NCRT, favorable IPRFS and pathological complete response was achieved with NCRT followed by TME. Further studies combining patient customized RT dose with systemic therapies are needed.

Hyperthermic pressurized intraperitoneal aerosol drug delivery system in a large animal model: a feasibility and safety study.

BACKGROUND: We developed a novel drug delivery system called hyperthermic pressurized intraperitoneal aerosol chemotherapy (HPIPAC) that hybridized Hyperthermic intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC). The present study aims to assess the feasibility and safety of HPIPAC system in a large animal survival model. METHODS: Eleven pigs (eight non-survival models and three survival models) were used in the experiment. The heat module in the HPIPAC controller circulates hyperthermic CO2 in a closed-loop circuit and creates gas-based dry intraperitoneal hyperthermia. Three 12 mm trocars were placed on the abdomen. The afferent CO2 tube wound with heat generating coil was inserted into a trocar, and the efferent tube was inserted into another trocar. Heated CO2 was insufflated and circulated in a closed circuit until the intra-abdominal and peritoneal surface temperature reached 42 °C. 100 ml of 5% dextrose in water was nebulized for 5 min and the closed-loop circulation was resumed for 60 min at 42 °C. Tissue biopsies were taken from several sites from the pigs in the survival model. RESULTS: The average change in core temperature of the pigs was 2.5 ± 0.08 °C. All three pigs displayed no signs of distress, and their vital signs remained stable, with no changes in their diet. In autopsy, inflammatory and fibrotic responses at the biopsy sites were observed without serious pathologic findings. CONCLUSIONS: We successfully proved the feasibility and safety of our novel HPIPAC system in an in-vivo swine survival model.

Sex-dependent different clinicopathological characterization of Epstein-Barr virus-associated gastric carcinoma: a large-scale study.

BACKGROUND: Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) has been reported to account for approximately 5-16% of all GCs with good prognosis compared to EBV-negative GC. We evaluated the clinicopathological characteristics of EBVaGC including survival rate in South Korea. METHODS: A total of 4,587 patients with GC who underwent EBV in situ hybridization (EBV-ISH) were prospectively enrolled at the Seoul National University Bundang Hospital from 2003 to 2021. Age, sex, smoking status, cancer type and stage, tumor size and location, histological type, molecular features and survival information were analyzed. RESULTS: A total of 456 patients with GC (9.9%) were positive for EBV. The EBVaGC group displayed a higher proportion of males (P < 0.001), a predominant presence in the proximal stomach (P < 0.001), a higher proportion of undifferentiated cancer (P < 0.001), and a lower cancer stage (P = 0.004) than the EBV-negative group. Cox multivariate analyses revealed age (hazard ratio [HR] = 1.025, P < 0.001), tumor size (HR = 1.109, P < 0.001), and cancer stage (stage2 HR = 4.761, P < 0.001; stage3 HR = 13.286, P < 0.001; stage4 HR = 42.528, P < 0.001) as significant risk factors for GC-specific mortality, whereas EBV positivity was inversely correlated (HR = 0.620, P = 0.022). Furthermore, the EBVaGC group displayed statistically significant survival advantages over the EBV-negative cancer group in terms of both overall (P = 0.021) and GC-specific survival (P = 0.007) on the Kaplan-Meier survival curve. However, this effect was evident only in males. CONCLUSIONS: EBVaGC patients showed better prognoses despite their association with proximal location and poorly differentiated histology in male, probably due to the difference in immunity between males and females.

Genomic and Transcriptomic Characterization of Gastric Cancer with Bone Metastasis.

PURPOSE: Bone metastasis (BM) adversely affects the prognosis of gastric cancer (GC). We investigated molecular features and immune microenvironment that characterize GC with BM compared to GC without BM. MATERIALS AND METHODS: Targeted DNA and whole transcriptome sequencing were performed using formalin-fixed paraffin-embedded primary tumor tissues (gastrectomy specimens) of 50 GC cases with distant metastases (14 with BM and 36 without BM). In addition, immunohistochemistry (IHC) for mucin-12 and multiplex IHC for immune cell markers were performed. RESULTS: Most GC cases with BM had a histologic type of poorly cohesive carcinoma and showed worse overall survival (OS) than GC without BM (p < 0.05). GC with BM tended to have higher mutation rates in TP53, KDR, APC, KDM5A, and RHOA than GC without BM. Chief cell-enriched genes (PGA3, PGC, and LIPF), MUC12, MFSD4A, TSPAN7, and TRIM50 were upregulated in GC with BM compared to GC without BM, which was correlated with poor OS (p < 0.05). However, the expression of SERPINA6, SLC30A2, PMAIP1, and ITIH2 were downregulated in GC with BM. GC with BM was associated with PIK3/AKT/mTOR pathway activation, whereas GC without BM showed the opposite effect. The densities of helper, cytotoxic, and regulatory T cells did not differ between the two groups, whereas the densities of macrophages were lower in GC with BM (p < 0.05). CONCLUSION: GC with BM had different gene mutation and expression profiles than GC without BM, and had more genetic alterations associated with a poor prognosis.

Analysis of Characteristics and Risk Factors of Patients with Single Gastric Cancer and Synchronous Multiple Gastric Cancer among 14,603 Patients.

Background/Aims: Synchronous multiple gastric cancer (SMGC) accounts for approximately 6% to 14% of gastric cancer (GC) cases. This study aimed to identify risk factors for SMGC. Methods: A total of 14,603 patients diagnosed with GC were prospectively enrolled. Data including age, sex, body mass index, smoking, alcohol consumption, family history, p53 expression, microsatellite instability, cancer classification, lymph node metastasis, and treatment were collected. Risk factors were analyzed using logistic regression analysis between a single GC and SMGC. Results: The incidence of SMGC was 4.04%, and that of early GC (EGC) and advanced GC (AGC) was 5.43% and 3.11%, respectively. Patients with SMGC were older (65.33 years vs 61.75 years, p<0.001) and more likely to be male. Lymph node metastasis was found in 27% of patients with SMGC and 32% of patients with single GC. Multivariate analysis showed that SMGC was associated with sex (male odds ratio [OR], 1.669; 95% confidence interval [CI], 1.223 to 2.278; p=0.001), age (≥65 years OR, 1.532; 95% CI, 1.169 to 2.008; p=0.002), and EGC (OR, 1.929; 95% CI, 1.432 to 2.600; p<0.001). Survival rates were affected by Lauren classification, sex, tumor size, cancer type, distant metastasis, and venous invasion but were not related to the number of GCs. However, the survival rate of AGC with SMGC was very high. Conclusions: SMGC had unique characteristics such as male sex, older age, and EGC, and the survival rate of AGC, in which the intestinal type was much more frequent, was very good (Trial registration number: NCT04973631).

Treatment Patterns and Prognosis of Palliative Chemotherapy Combined With Targeting Agents in Patients With Unresectable Metastatic Colorectal Cancer: CHOICE, A Multicenter Longitudinal Observational Study.

BACKGROUND/AIM: This study investigated the treatment patterns and prognosis of patients with metastatic or unresectable colorectal cancer (mCRC) treated with chemotherapy with targeting agents. PATIENTS AND METHODS: This longitudinal multicenter study included 963 patients with mCRC who were treated in Korea between 2016 and 2020. Treatment patterns and efficacy were compared according to the mutation status and clinical factors. RESULTS: As first-line therapy, most of the patients (83.5%) received FOLFOX plus bevacizumab (35.4%), followed by FOLFIRI plus bevacizumab (18.8%), FOLFIRI plus cetuximab (17.0%), and FOLFOX plus cetuximab (12.3%). Bevacizumab was the most frequent agent (78.8%) combined with chemotherapy in RAS-mutated CRC, while cetuximab (57.2%) in RAS wild-type CRC. Cetuximab was frequently combined with a doublet regimen in patients with left-sided CRC than in those with right-sided CRC (34.4% vs. 16%). As second-line therapy, most patients (63.4%) also received doublet regimens with bevacizumab, and FOLFIRI plus aflibercept was administered in 15.1%. The objective response rate with FOLFIRI plus cetuximab was significantly higher in patients with left-sided CRC than in those with right-sided CRC (59.2% vs. 30.8%, p=0.008) and marginally higher in patients with RAS wild-type CRC than in those with RAS-mutated CRC (55.6% vs. 0.0%, p=0.092). Progression-free survival (PFS) with FOLFOX plus bevacizumab was significantly shorter than that with FOLFIRI plus bevacizumab (p=0.030) in RAS-mutated CRC, whereas there were no significant differences between regimens in RAS wild-type CRC. CONCLUSION: In patients with unresectable metastatic colorectal cancer, doublet chemotherapy with targeting agents is the most common therapy and efficacy depends on the mutation status as well as clinical factors.

Single-port intragastric wedge resection using the tunnel method: a novel surgical approach for treating endophytic gastric subepithelial tumors.

BACKGROUND: Intragastric wedge resection is an effective method for treating endophytic gastric subepithelial tumors (SETs). However, retracting the stomach wall to the umbilicus is difficult in certain patients. In response, we developed a novel surgical technique for single-port intragastric wedge resection, which we termed the "tunnel method." METHODS: A transumbilical incision is made, and a wound retractor is applied. After diagnostic laparoscopy, a gastrostomy is made on the greater curvature, lower body. Another small wound retractor is inserted into the gastrostomy, and extracted through the transumbilical incision, creating a tunnel from the gastrostomy site to the umbilicus. Articulating laparoscopic instruments are inserted via the tunnel, and intragastric wedge resection is performed. We collected and analyzed the clinicopathologic and operative data of patients who underwent intragastric wedge resection via the tunnel method. RESULTS: Twenty-seven patients who underwent single-port intragastric wedge resection via the tunnel method in a single tertiary referral hospital were included in this study. The mean age of the patients was 54.6 ± 11.4 years, body mass index was 26.5 ± 3.4 kg/m2. Twenty-four (88.9%) patients had tumors located in the upper third of the stomach. The average operative time was 65.0 ± 24.2 min. None of the patients experienced Clavien-Dindo grade IIIa or higher postoperative complications. The average postoperative hospital stay length was 2.5 ± 0.8 days. Thirteen gastrointestinal stromal tumors, nine leiomyomas, and one neuroendocrine carcinoma, schwannoma, lipoma, spindle cell proliferative lesion, and fibrotic lesion were pathologically diagnosed. The average tumor size was 2.6 ± 1.3 cm. All cases had negative resection margins. CONCLUSIONS: Single-port intragastric wedge resection by the tunnel method is a feasible and safe approach for treating endophytic gastric SETs.

Alterations in gastric and gut microbiota following sleeve gastrectomy in high-fat diet-induced obese rats.

Obesity is considered a high-risk disease and a global epidemic, and the number of obese patients is rising at an alarming rate worldwide. High-fat diet-induced dysbiosis of the intestinal microbiota is considered an essential factor related to obesity. Bariatric surgery induces a sharp decrease in fat content and effectively improves the metabolism of obese individuals. Herein, we aimed to investigate the effects of a high-fat diet-induced obesity and the alterations in gastric and intestinal microbiota resulting from sleeve gastrectomy on clinical outcomes. We performed 16S sequencing of gastric and fecal samples obtained from rats in three treatment groups: normal chow diet, high-fat diet (HFD), and sleeve gastrectomy after HDF for 14 weeks. The area under the curve of fasting glucose and the levels of leptin and low-density lipoproteins were significantly different between groups. Microbial taxa that were highly correlated with several clinical parameters were identified for each group. Glyoxylate and dicarboxylate, taurine and hypotaurine, butanoate, nitrogen, and pyrimidine metabolism and aminoacyl-transfer ribonucleic acid biosynthesis were affected by bariatric surgery and were significantly associated with changes in the composition of gastric and fecal microbiomes. Connectivity and co-occurrence were higher in fecal samples than in gastric tissues. Our results elucidated the positive effects of sleeve gastrectomy in obesity and shed light on changes in the microbiomes of gastric and fecal samples.

Effect of human epidermal growth factor receptor 2 overexpression in metastatic colorectal cancer on standard chemotherapy outcomes.

Background: In metastatic colorectal cancer (mCRC), the prognostic relevance of the human epidermal growth factor receptor-2 (HER2) remains controversial. We evaluated the impact of HER2 overexpression on outcomes of standard chemotherapy in patients with mCRC. Methods: This retrospective study included patients with mCRC who received standard chemotherapy for mCRC and were tested for HER2 expression at Samsung Medical Center, Seoul, Korea, between January 15, 2017, and February 05, 2022. The HER2 test was performed using immunohistochemistry. We assessed the objective response rate (ORR), overall survival (OS), and progression-free survival (PFS) according to HER2 status. All statistical analyses were performed using SPSS® version 25 (IBM, Armonk, NY, USA). Results: In total, 108 patients were included; 10 (9.3%) had HER2-positive tumors. The ORR for patients with mCRC receiving standard chemotherapy did not differ for HER2-positive and HER2-negative tumors. The median PFS for patients with mCRC with HER2-positive or HER2-tumors after receiving first-line chemotherapy was 18.52 months [95% confidence interval (CI): 4.355-32.695] or 10.95 months (95% CI: 9.317-12.585; P=0.417), respectively, and that after second-line chemotherapy was 7.08 months (95% CI: 6.801-7.363) or 5.34 months (95% CI: 4.433-6.255; P=0.837), respectively. Likewise, OS did not differ according to HER2 expression (median OS: HER2-positive tumors, 49.1 months (95% CI: 0.000-98.365); HER2-negative tumors, 37.7 months (95% CI: 27.111-48.366; P=0.410). Conclusions: The tumor response and survival of patients with mCRC after standard chemotherapy did not differ by HER2 expression. These findings suggest that the status of HER2 expression need not be considered when choosing regimens as the current first- and second-line treatments.

The Shorr Versus Modified Ultrafast Papanicolaou Method for Intraoperative Diagnosis of Peritoneal Washing Cytology in Advanced Gastric Cancer: A Phase II Study.

PURPOSE: According to the American Joint Committee on Cancer cancer staging system, positive peritoneal washing cytology (PWC) indicates stage IV gastric cancer. However, rapid intraoperative diagnosis of PWC has no established reliable method. This study evaluated and compared the diagnostic accuracy of the Shorr and the modified ultrafast Papanicolaou (MUFP) methods for intraoperative PWC. MATERIALS AND METHODS: This study included patients with gastric cancer who were clinically diagnosed with stage cT3 or higher. The Shorr and MUFP methods were performed on all PWC specimens, and the results were compared with those of conventional Papanicolaou (PAP) staining with carcinoembryonic antigen immunohistochemistry. Sensitivity, specificity, and partial likelihood tests were used to compare the 2 methods. RESULTS: Forty patients underwent intraoperative PWC between November 2019 and August 2021. The average time between specimen reception and slide preparation using Shorr and MUFP methods was 44.4±4.5 minutes, and the average time between specimen reception and pathologic diagnosis was 53.9±8.9 minutes. Eight patients (20.0%) had positive cytology in PAP staining. The Shorr method had a sensitivity of 75.0% and specificity of 93.8%; the MUFP method had 62.5% sensitivity and 100.0% specificity. The area under the curve was 0.844 for Shorr and 0.813 for MUFP. In comparing the C-indices of each method with overall survival, no difference was found among the Shorr, MUFP, and conventional PAP methods. CONCLUSIONS: The Shorr and MUFP methods are acceptable for the intraoperative diagnosis of PWC in advanced gastric cancer.

Feasibility and safety of pure single-incision laparoscopic total and proximal gastrectomy for early gastric cancer: propensity score-matched comparison to multiport totally laparoscopic approach.

BACKGROUND: There have been few studies regarding the feasibility and safety of pure single-incision laparoscopic total gastrectomy (SITG) or proximal gastrectomy (SIPG) for early gastric cancer (EGC). The purpose of this study was to analyze the surgical outcome of all consecutive SITG or SIPG cases compared with multiport laparoscopic total gastrectomy (MLTG) or proximal gastrectomy (MLPG) for EGC. METHODS: We analyzed all consecutive SITG or SIPG cases with double-tract reconstruction for ECG, including the initial case, between March 2013 and December 2021. SITG/SIPG was performed on patients without significant systemic comorbidities through a 3-4 cm vertical transumbilical incision. SITG/SIPG was matched to multiport laparoscopic total or proximal gastrectomy (MLTG/MLPG) cases performed in the same period using a 1:3 propensity score matching, including sex, body mass index (BMI), age and type of resection, year of operation, and institution as covariates. We compared perioperative clinicopathological characteristics and early postoperative morbidity within 1 month after surgery between the SITG/SIPG and MLTG/MLPG groups. RESULTS: In total, 21 patients with SITG and 15 patients with SIPG were compared with those with MLTG (n = 264) and MLPG (n = 220). No conversion to an open or multiport approach occurred in the SITG/SIPG group. After matching, operation time was similar between SITG/SIPG and MLTG/MLPG (223.9 ± 63.5 min vs 234.8 ± 68.7 min, P = 0.402). Length of stay was not significantly different between SITG/SIPG and MLTG/MLPG (11.9 ± 15.4 days vs 8.4 ± 5.0 days, P = 0.210). The average number of retrieved lymph nodes was not significantly different between SITG and MLTG (53.1 ± 16.3 vs 63.2 ± 27.5, P = 0.115), but it was significantly higher in SIPG than MLPG (59.6 ± 27.2 vs 46.0 ± 19.7, P = 0.040). The overall complication rate (30.6% vs 25.9%, P = 0.666) and Clavien-Dindo grade III or higher complication rates (13.9% vs 6.5%, P = 0.175) were not significantly different between the SITG/SIPG and MLTG/MLPG groups. CONCLUSION: Cautious adoption of SITG/SIPG procedures for EGC is feasible and safe.

Smoking Cessation and Pancreatic Cancer Risk in Individuals With Prediabetes and Diabetes: A Nationwide Cohort Study.

BACKGROUND: Individuals with diabetes and prediabetes are at increased risk of pancreatic cancer. However, little is known about the effects of smoking or smoking cessation on pancreatic cancer risk in individuals with diabetes and prediabetes. We investigated the association between smoking status (particularly smoking cessation) and pancreatic cancer risk according to glycemic status. PATIENTS AND METHODS: This nationwide cohort study included 9,520,629 adults without cancer who underwent the Korean National Health Screening in 2009 and were followed until 2018. Hazard ratios and 95% confidence intervals for pancreatic cancer were estimated after adjusting for potential confounders. RESULTS: During the 78.4 million person-years of follow-up, 15,245 patients were newly diagnosed with pancreatic cancer. Among individuals with diabetes and prediabetes, current smoking synergistically increased pancreatic cancer risk (all P<.01). However, quitters with diabetes and prediabetes had a pancreatic cancer risk comparable to that of never-smokers (all P>.05). For pancreatic cancer in current smokers, quitters, and never-smokers, respectively, the hazard ratios were 1.48 (95% CI, 1.40-1.58), 1.11 (95% CI, 1.03-1.19), and 1.00 (reference) among individuals with normoglycemia; 1.83 (95% CI, 1.70-1.97), 1.28 (95% CI, 1.18-1.39), and 1.20 (95% CI, 1.14-1.26) among individuals with prediabetes; and 2.72 (95% CI, 2.52-2.94), 1.78 (95% CI, 1.63-1.95), and 1.63 (95% CI, 1.54-1.72) among individuals with diabetes. There were no differences in risk between quitters with a <20 pack-year smoking history and never-smokers in all glycemic status groups. CONCLUSIONS: Pancreatic cancer risk synergistically increased in current smokers with diabetes and prediabetes. However, smoking cessation reduced the synergistically increased risk of pancreatic cancer to the level of never-smokers, especially when smoking history was <20 pack-years. More individualized and intensive cancer prevention education should be underscored for individuals at an increased risk of pancreatic cancer beyond the one-size-fits-all approach.

Feasibility of articulating laparoscopic instruments in laparoscopic gastrectomy using propensity score matching.

Advancements in minimally invasive surgery has led to the development of several surgical instruments, including the ArtiSential®. This new instrument provides a greater range of motion and improved dexterity to laparoscopic procedures, making it an alternative option to traditional straight instruments, and the Da Vinci robot system. The purpose of this study is to compare the postoperative outcomes of a prospective cohort of patients who underwent laparoscopic gastrectomy using articulating instruments with those of a historical cohort of patients who underwent the same procedure using straight instruments. The study was designed as a prospective observational cohort study matched to a retrospective historical cohort using propensity score matching. The primary outcome was the rate of early complications within 90 days of surgery. Other outcomes included the operation time, estimated blood loss, time to first flatus, time to first soft fluid diet, hospital stay, and mortality. After propensity score matching, 41 patients were enrolled in both groups. The mean age was 62.4 ± 12.3 years in the conventional group and 63.5 ± 9.6 years in the artisential group (p = 0.647). Mean operative time was significantly shorter in the artisential group compared to the conventional group (136.1 min vs. 163.9 min, p = 0.032). The time to first soft fluid diet was also significantly shorter in the artisential group (2.2 days vs. 2.8 days, p = 0.030), but there was no significant difference in the time to first flatus and overall hospital stay. The incidence of early complications was lower in the artisential group, but the difference was not significant (24.4% vs 7.3%, p = 0.070). There was no mortality in either group. The use of articulating instruments for laparoscopic gastrectomy did not increase postoperative morbidity compared to straight laparoscopic instruments. The use of articulating instruments may be associated with faster bowel recovery and less early complications.

Outcome Analysis of Combined Surgical Approaches in Advanced-stage Upper Extremity Breast Cancer-related Lymphedema.

Background: This study aimed to discuss several surgical approaches for advanced-stage breast cancer-related lymphedema and compared their treatment outcomes. Methods: The patients who underwent surgery with International Society of Lymphology stage III lymphedema were included in this study. The three surgical methods used here were (1) suction-assisted lipectomy with lymphovenous anastomosis, (2) autologous breast reconstruction with muscle-sparing transverse rectus abdominis muscle flap combined with inguinal lymph node transfer, and (3) vascularized lymph node transfer with free omental flap. Analysis of the postoperative outcomes in the patients was based on the difference in volume between patients pre- and postoperatively, LYMPH-Q questionnaire, and bioelectrical impedance analysis. Results: Eighty-seven patients with stage IIb or higher disease underwent surgery. 38 patients underwent suction-assisted lipectomy + lymphovenous anastomosis, 23 underwent autologous breast reconstruction with vascularized lymph node transfer + lymphovenous anastomosis, and 26 underwent right gastroepiploic omental vascularized lymph node transfer with lymphovenous anastomosis. The LYMPH-Q questionnaire, which evaluates patients' subjective satisfaction, showed that the autologous breast reconstruction group showed the greatest improvement, whereas in bioimpedance analysis, the omental flap group demonstrated the greatest postoperative improvement compared with preoperative values. However, suction-assisted lipectomy was considered the most effective surgical method for reducing limb volume in patients with high-stage lymphedema accompanied by fibrosis and volume increase. Conclusions: We observed slightly different clinical effects for each surgical method; however, all surgical methods demonstrated a reduction in the degree of edema and an increase in patient satisfaction.

Comprehensive molecular analysis to predict the efficacy of chemotherapy containing bevacizumab in patients with metastatic colorectal cancer.

Background: Although bevacizumab is an important treatment for metastatic colorectal cancer (CRC), not all patients with CRC benefit from it; in unselected patient populations, only modest survival benefits have been reported. Methods: We evaluated clinical outcomes in 110 patients using comprehensive molecular characterization to identify biomarkers for a response to bevacizumab-containing treatment. The molecular analysis comprised whole-exome sequencing, ribonucleic acid sequencing, and a methylation array on patient tissues. Results: Genomic and molecular characterization was successfully conducted in 103 patients. Six of 103 CRC samples were hypermutated, and none of the non-hypermutant tumors were microsatellite unstable. Among those 103 patients, 89 had adenocarcinoma (ADC), 15 were diagnosed with mucinous ADC, and six had signet-ring cell carcinoma (SRCC). Consensus molecular subtype (CMS) 2 was unique to ADC. Of the four SRCCs, two were CMS1, one was CMS4, and the other was CMS3. APC mutation status was a significantly enriched factor in responders to bevacizumab treatment. Fibroblast growth factor receptor (FGFR) 1/2 signaling was upregulated in non-responders, whereas cell cycle, transfer ribonucleic acid processing, nucleotide excision repair, and oxidative phosphorylation pathways were enriched in responders. In addition, IGF1 was differentially expressed in non-responders (log2 fold change = -1.43, p = 4.11 × 10-5, false discovery rate = 0.098), and FLT1 was highly methylated in non-responders (p = 7.55 × 10-3). When the molecular pathways were reanalyzed separately according to the backbone chemotherapy (FOLFOX vs. FOLFIRI), the significance of the molecular pathways varied according to the backbone chemotherapy. Conclusions: This study sought a subset of CRC patients with a distinct clinical response to chemotherapy containing bevacizumab. Our results need to be validated in a large group of homogenous patient cohort and examined according to the different chemotherapy backbones to create personalized therapeutic opportunities in CRC.

Tumor mutation burden in gastro-entero-pancreatic-neuroendocrine neoplasms.

Background: As rare tumors, there are limited treatment options for neuroendocrine neoplasms (NENs). Recently, microsatellite instability (MSI) and tumor mutation burden (TMB) have been emerging as potential biomarkers in various tumors. However, there is a lack of research on the use of these biomarkers in gastro-entero-pancreatic (GEP)-NENs. Methods: We analyzed 31 patients diagnosed with GEP-NEN between 2013 to 2022. The TMB and MSI analyses using next-generation sequencing (NGS) were performed for all patients. The TruSightTM Oncology 500 assay from Illumina was used as the NGS panel. Results: Out of the 31 patients analyzed, the most frequent primary origin was the pancreas (12 patients, 38.7%), followed by the stomach (4 patients, 12.9%), gallbladder (4 patients, 12.9%), rectum (7 patients, 22.6%), small bowel (2 patients, 6.5%), and bile duct (1 patient, 3.2%). Among these patients, 19 (61.3%) were diagnosed with well-differentiated neuroendocrine tumors, with grade 2 being the most common (15 patients, 48.4%), followed by grade 3 (3 patients, 9.7%) and grade 1 (1 patient, 3.2%). Neuroendocrine carcinoma was confirmed in 12 patients (38.7%). The median number of metastases was 2.0 [interquartile range (IQR), 1.0-3.0], and the liver was the most common site of metastasis (23 patients, 74.2%). The median TMB was 4.7 (IQR, 3.1-6.3) mutations/Mb, and all tumors were classified as microsatellite stability (MSS). Only one patient had a high TMB (266.4 mutations/Mb), which was a grade 3 neuroendocrine tumor originating from the pancreas. The TMB value did not vary depending on the primary tumor site or World Health Organization (WHO) grade. Conclusions: This analysis showed that, despite very low incidence, there are GEP-NENs with high TMB. For precision medicine, testing for MSI and TMB is needed for this tumor type.

Pemetrexed and Erlotinib as a Salvage Treatment in Patients With Metastatic Biliary Tract Cancer Who Failed Gemcitabine-containing Chemotherapy: A Phase II Single-arm Prospective Study.

BACKGROUND/AIM: No standard treatment is currently recommended for advanced biliary tract cancer (BTC) after first-line therapy with gemcitabine plus cisplatin. We aimed to evaluate the efficacy and safety of a pemetrexed and erlotinib combination in patients with BTC previously treated with gemcitabine. PATIENTS AND METHODS: This phase II, open-label, single-arm study enrolled patients with BTC who had previously failed gemcitabine-based first-line chemotherapy. Patients were treated with pemetrexed as a 500 mg/m2 intravenous infusion on day 1 for three weeks and erlotinib 100 mg daily until disease progression or unacceptable toxicity. The primary endpoint was the overall response rate (ORR). RESULTS: The study enrolled 20 patients with BTC, including 12 (60%) with intrahepatic cholangiocarcinoma (IHCC), 3 (15%) with extrahepatic cholangiocarcinoma (EHCC), and 5 (25%) with gallbladder cancer (GBC). The ORR was 5%, and the disease control rate (DCR) was 55%. As of the cutoff point of March 31, 2023, the median progression-free survival (PFS) was 2.3 months [95% confidence interval (CI)=0.00-4.74] and the median overall survival (OS) was 5.6 months (95%CI=2.28-8.87). Patients with EHCC showed longer PFS and OS compared to patients with IHCC or GBC, but the differences were not significant. A baseline CEA greater than the upper normal limit was the only significant prognostic factor for a worse OS rate. The only treatment-related adverse event (TRAE) with severity grade ≥3 was anemia (5%). CONCLUSION: Salvage chemotherapy with pemetrexed plus erlotinib was well-tolerated and showed marginal clinical activity in BTC patients after failure to gemcitabine-based chemotherapy.

Evaluation of hormonal and circulating inflammatory biomarker profiles in the year following bariatric surgery.

Background: Bariatric surgery (BS) has a superior effect on reducing body weight and fat in patients with morbid obesity. As a result, BS mitigates obesity-related complications such as type 2 diabetes (T2D). However, few studies have shown the mechanism underlying diabetes remission after surgery. This study aimed to investigate the differences in serum hormone and inflammatory cytokine levels related to diabetes before surgery and during 12 months of follow-up in Korean patients with obesity. Methods: The study participants were patients with morbid obesity (n=63) who underwent sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) between 2016 - 2017 at seven tertiary hospitals in Korea. The patients were followed for 1 year after surgery. Results: Sixty-three patients had significant weight loss after surgery and showed improvements in clinical parameters and hormonal and inflammatory profiles. Among them, 23 patients who were diabetic preoperatively showed different remission after surgery. The levels of inflammation-related clinical parameters changed significantly in the remission group, and serum inflammatory cytokine and hormones significantly decreased at certain points and showed an overall decreasing trend. Conclusions: Our study found postoperative changes of factors in blood samples, and the changes in hormones secreted from the three major metabolic tissue (pancreas, adipose, and gut) along with the differences in multi-origin inflammatory cytokines between remission and non-remission groups provide a path for understanding how the effect of BS in improving glucose metabolism is mediated.