Risk Factors for Long-term Body Weight Loss After Proximal Gastrectomy: A Retrospective Analysis.

BACKGROUND/AIM: Proximal gastrectomy (PG) is a therapy for early-stage proximal gastric cancer and offers advantages such as the preservation of food storage capacity and less body weight loss (BWL). Nevertheless, significant BWL following PG may occur, affecting the patient's well-being and survival. In this study, we aimed to identify the relevant factors for BWL following PG by analyzing an institutional database of patients. PATIENTS AND METHODS: We enrolled 58 consecutive patients who underwent PG for gastric or esophagogastric junction cancer at our institution between April 2004 and March 2021. Based on BWL at 12 months postoperatively, we retrospectively compared and examined patient characteristics, surgical details, and nutritional markers. RESULTS: The mean BWL of the 58 patients included in this analysis was 14.0±7.2%. When the patients were divided into BWL-moderate (n=29) and BWL-severe (n=29) groups using a cutoff value of 15.7%, the latter experienced early BWL within 1 month postoperatively, primarily due to body fat mass reduction, with no recovery during the 60 months of follow up. In contrast, gradual recovery was observed among patients in the BWL-moderate group after experiencing the lowest body weight 24 months postoperatively. A greater decrease in body fat mass than in muscle mass was observed in both groups. Blood hemoglobin levels did not recover in the BWL-severe group. CONCLUSION: The BWL-severe group after proximal gastrectomy demonstrated significantly greater early postoperative BWL, primarily attributed to a reduction in body fat mass, with hardly any recovery. Early postoperative nutritional intervention might be proposed to prevent long-term BWL.

Real-time ultrasound-guided thoracentesis simulation using an optical see-through head-mounted display: a proof-of-concept study.

Aim: This study aimed to examine the feasibility and potential benefits of an optical see-through head-mounted display (OST-HMD) during real-time ultrasound-guided thoracentesis simulations. Material and methods: Six physicians performed a thoracentesis simulation using an OST-HMD and a wireless image transmission system. The time required, puncture needle visibility, pleural fluid collection success rate, and head movement during the procedure using a smart glass equipped with an inertial measurement unit were all recorded and compared with and without the HMD. Results: Study participants successfully extracted effusions in all procedures. The use of OST-HMD did not significantly affect the time of the procedure, but notably decreased the horizontal and vertical head movements during the procedure. Conclusions: The study demonstrated the feasibility of using an OST-HMD in a simulated real-time ultrasound-guided thoracentesis procedure and showed the potential of HMD in thoracentesis to improve ergonomics and accuracy. Further research is necessary to confirm these findings.

Proposal of the Second Cutoff of Serum Carcinoembryonic Antigen Levels to Stratify Patients into Low, Intermediate, and High Risks at Recurrences after Curative Resection of Gastric Cancer.

INTRODUCTION: Carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 are widely used for treating various cancers, with cutoff values of 5.0 ng/mL and 37.0 IU/mL, respectively. However, these cutoff values are not for specific diseases or purposes but are uniformly used for any disease and any purpose. It is also unclear as to whether patients are at equal risk of recurrence if they are below the cutoff values. This study aimed to investigate the optimal cutoff of serum tumor markers in the stratification of recurrence risk after curative resection of gastric cancer. METHODS: We constructed a nine-center integrated database of patients who received gastrectomy between January 2010 and December 2014 with a 5-year follow-up period. We determined the cutoff value of preoperative serum tumor marker levels correlated with postoperative recurrences and evaluated its performance in risk stratification for recurrences in 948 patients with stage II/III gastric cancer who underwent radical resection. RESULTS: The hazard ratio for postoperative recurrences increased at two points of preoperative CEA levels, 3.6 ng/mL and 5.0 ng/mL, which were set as cutoffs. These two cutoffs stratified relapse-free survival into three levels. CONCLUSIONS: By adding a second cutoff value for preoperative serum CEA, which was proposed specifically for the prediction of recurrences, patients can be stratified into low-, intermediate-, and high-risk recurrences after curative resection of gastric cancer.

Investigation into Molecular Brain Aging in Senescence-Accelerated Mouse (SAM) Model Employing Whole Transcriptomic Analysis in Search of Potential Molecular Targets for Therapeutic Interventions.

With the progression of an aging society, cognitive aging has emerged as a pressing concern necessitating attention. The senescence-accelerated mouse-prone 8 (SAMP8) model has proven instrumental in investigating the early stages of cognitive aging. Through an extensive examination of molecular changes in the brain cortex, utilizing integrated whole-genome transcriptomics, our principal aim was to uncover potential molecular targets with therapeutic applications and relevance to drug screening. Our investigation encompassed four distinct conditions, comparing the same strain at different time points (1 year vs. 16 weeks) and the same time point across different strains (SAMP8 vs. SAMR1), namely: physiological aging, accelerated aging, early events in accelerated aging, and late events in accelerated aging. Focusing on key functional alterations associated with aging in the brain, including neurogenesis, synapse dynamics, neurometabolism, and neuroinflammation, we identified candidate genes linked to these processes. Furthermore, employing protein-protein interaction (PPI) analysis, we identified pivotal hub genes involved in interactions within these functional domains. Additionally, gene-set perturbation analysis allowed us to uncover potential upstream genes or transcription factors that exhibited activation or inhibition across the four conditions. In summary, our comprehensive analysis of the SAMP8 mouse brain through whole-genome transcriptomics not only deepens our understanding of age-related changes but also lays the groundwork for a predictive model to facilitate drug screening for cognitive aging.

A Multicenter Randomized Phase II Trial Investigating the Effect of Polyglycolic Acid Sheet on the Prevention of Pancreatic Fistula After Gastrectomy with Prophylactic Lymph Node Dissection.

Pancreatic fistula after gastrectomy with lymph node dissection is associated with prolonged hospital stay and critical complications such as intra-abdominal bleeding and sepsis. Polyglycolic acid (PGA) sheets are absorbable suture reinforcement materials. A randomized Phase II trial has been planned to evaluate the effect of PGA sheets on preventing postoperative pancreatic fistula. A total of 320 patients will be recruited from thirteen institutions. Patients who are scheduled to undergo distal or total gastrectomy will be randomly allocated into the PGA group or control group, and the dissected area around the pancreas will be covered by the PGA sheet in the PGA group. The primary endpoint will be the maximum value of drain amylase concentration up to 5 days after surgery. The secondary endpoints will be as follows: transition of value of amylases of drain discharge, incidence of pancreatic fistula, incidence of intra-abdominal abscess, white blood cell count, value of C-reactive protein, incidence of postoperative complication, duration of antibiotic agents administration, duration of abdominal drainage, usage of octreotide, duration of hospital stay, incidence of bleeding in abdominal cavity, mortality, and incidence of reoperation.

High Preoperative Platelet to Lymphocyte Ratio Is Associated with a Greater Risk of Postoperative Complications and Hematogenous Recurrences in Esophageal Squamous Cell Carcinoma Patients Receiving Neoadjuvant Treatment.

INTRODUCTION: Neoadjuvant treatment is currently the gold standard for advanced esophageal squamous cell carcinoma (ESCC). Several studies have examined the value of blood count-based indexes for predicting short- and long-term outcomes after esophagectomy for ESCC, but the relative predictive value of pretreatment, preoperative, and postoperative indexes has not yet been examined. METHODS: This study included 320 patients with thoracic ESCC who underwent subtotal esophagectomy after neoadjuvant chemotherapy or chemoradiotherapy at our institution. A total of 19 candidate blood parameters were measured before neoadjuvant treatment as well as preoperatively and postoperatively. The ability of the parameters to predict postoperative complications, overall survival (OS), and relapse-free survival (RFS) was assessed using receiver operating characteristic (ROC) curve analysis and Cox regression analysis. RESULTS: ROC curve analysis indicated that preoperative platelet to lymphocyte ratio (PLR) had the best predictive value with an optimal cutoff value of 166. Patients with high preoperative PLR (≥166) had significantly shorter OS and RFS and significantly higher incidences of hematogenous recurrence and postoperative pneumonia compared with patients with low preoperative PLR (<166). In multivariate analysis, high preoperative PLR and high preoperative serum carcinoembryonic antigen level were independent predictors of poor prognosis. CONCLUSION: Preoperative PLR is a good predictor of short- and long-term prognosis in patients with advanced ESCC who receive neoadjuvant treatment followed by radical resection.

Modified Albumin-Bilirubin Grade optimized for risk stratification of patients with stage II-III gastric cancer.

PURPOSE: The albumin-bilirubin (ALBI) grade is calculated using albumin and bilirubin values. We determined the optimal cutoff value of the ALBI grade for predicting the postoperative prognosis of gastric cancer (GC). METHODS: We retrospectively reviewed a multicenter database of 3571 patients who underwent gastrectomy for GC between January 2010 and December 2014. The modified ALBI (mALBI) grade was determined using cutoff values: grade 1 (mALBI ≤ - 2.70), 2 (mALBI - 2.70 to - 2.10), and 3 (mALBI > - 2.10). We used a validation cohort to evaluate reproducibility. RESULTS: The entire cohort (n = 956) was randomly assigned to the learning or validation cohorts (n = 478 each). The former was categorized into the following groups by the preoperative mALBI grade: grade 1 (n = 235), grade 2 (n = 162), and grade 3 (n = 81). The disease-specific survival (DSS) rates of the learning and validation cohorts were significantly shortened in association with higher mALBI grade (learning, p = 0.0068; validation, p = 0.0100). A multivariate analysis revealed that mALBI grade 3 served as an independent prognostic factor for DSS. Furthermore, mALBI grade 2 or 3 was associated with a greater risk of disease-specific death in most subgroups. CONCLUSION: The mALBI grade accurately predicted the long-term postoperative prognosis of locally advanced GC.

Preoperative neutrophil-to-platelet ratio as a potential prognostic factor for gastric cancer with positive peritoneal lavage cytology in the absence of other non-curative factors: a multi-institutional dataset analysis.

PURPOSE: Peritoneal dissemination is the key to the prognosis of gastric cancer (GC) and can be detected early with peritoneal lavage cytology. No studies have examined preoperative prognostic factors in GC patients who have positive cytology but no other non-curative factors. METHODS: We conducted a retrospective analysis using a multicenter database of 3575 patients who underwent gastrectomy between 2010 and 2014. Patients with positive peritoneal lavage cytology as a sole non-curative factor were retrieved, and correlations between parameters and the prognosis were compared. RESULTS: A total of 66 patients were identified as eligible. In the receiver operating characteristic (ROC) curve analysis, the neutrophil-to-platelet ratio (NPR) had the greatest area under the curve value and was selected. We divided the NPR into two groups based on the optimal cutoff value of the NPR (2.000), as determined by the ROC curve analysis. A high preoperative NPR was the only prognostic factor. The NPR-high group had shorter overall survival than the NPR-low group (hazard ratio 1.85, 95% confidence interval 1.05-3.28, P = 0.032). CONCLUSION: Our analysis indicated that the preoperative NPR serves as a prognostic factor in GC patients with positive peritoneal lavage cytology in the absence of other non-curative factors.

A skeleton context-aware 3D fully convolutional network for abdominal artery segmentation.

PURPOSE: This paper aims to propose a deep learning-based method for abdominal artery segmentation. Blood vessel structure information is essential to diagnosis and treatment. Accurate blood vessel segmentation is critical to preoperative planning. Although deep learning-based methods perform well on large organs, segmenting small organs such as blood vessels is challenging due to complicated branching structures and positions. We propose a 3D deep learning network from a skeleton context-aware perspective to improve segmentation accuracy. In addition, we propose a novel 3D patch generation method which could strengthen the structural diversity of a training data set. METHOD: The proposed method segments abdominal arteries from an abdominal computed tomography (CT) volume using a 3D fully convolutional network (FCN). We add two auxiliary tasks to the network to extract the skeleton context of abdominal arteries. In addition, our skeleton-based patch generation (SBPG) method further enables the FCN to segment small arteries. SBPG generates a 3D patch from a CT volume by leveraging artery skeleton information. These methods improve the segmentation accuracies of small arteries. RESULTS: We used 20 cases of abdominal CT volumes to evaluate the proposed method. The experimental results showed that our method outperformed previous segmentation accuracies. The averaged precision rate, recall rate, and F-measure were 95.5%, 91.0%, and 93.2%, respectively. Compared to a baseline method, our method improved 1.5% the averaged recall rate and 0.7% the averaged F-measure. CONCLUSIONS: We present a skeleton context-aware 3D FCN to segment abdominal arteries from an abdominal CT volume. In addition, we propose a 3D patch generation method. Our fully automated method segmented most of the abdominal artery regions. The method produced competitive segmentation performance compared to previous methods.

Risk score for predicting death from other causes after curative gastrectomy for gastric cancer.

BACKGROUND: The number of patients who die from causes other than gastric cancer after R0 resection is increasing in Japan, due in part to the aging population. However, few studies have comprehensively investigated the clinicopathological risks associated with deaths from other causes after gastrectomy. This study aimed to build a risk score for predicting such deaths. METHODS: We retrospectively reviewed clinical data for 3575 patients who underwent gastrectomy for gastric cancer at nine institutions in Japan between January 2010 and December 2014. RESULTS: The final study population of 1758 patients were assigned to Group A (n = 187): patients who died from other causes within 5 years of surgery, and Group B (n = 1571): patients who survived ≥ 5 years after surgery. Multivariate analysis identified nine characteristics as risk factors for poor survival: age ≥ 75 years, male sex, body mass index < 22 kg/m2, Eastern Cooperative Oncology Group Performance Status (≥ 1), diabetes mellitus, cardiovascular/cerebrovascular disease, other malignant diseases, preoperative albumin level < 3.5 g/dL, and total gastrectomy. Patients with risk scores of 0-2, 3-4, or 5-9 (based on 1 point per characteristics) were classified into Low-risk, Intermediate-risk, and High-risk groups, respectively. The 5-year survival rates were 96.5%, 85.3%, and 56.5%, for the Low-, Intermediate-, and High-risk groups, respectively, and the hazard ratio (95% confidence intervals) was 16.33 (10.85-24.58, p < 0.001) for the High-risk group. CONCLUSIONS: The risk score defined here may be useful for predicting deaths from other causes after curative gastrectomy.

Preoperative indocyanine green fluorescence injection to accurately determine a proximal margin during robotic distal gastrectomy.

INTRODUCTION: Adequate surgical margins following gastrectomy for gastric cancer are required. In addition, a method for accurately detecting tumor location without palpation is needed during robotic surgery. Although several methods have been reported, most of these either lack accuracy or require increased time and effort during intraoperative detection. Herein, we introduce a new method for detecting tumor location using preoperative indocyanine green (ICG) marking and the built-in ICG detection system of the da Vinci Xi Surgical System in robotic gastrectomy to determine appropriate surgical margins. MATERIALS AND SURGICAL TECHNIQUE: We used this method to determine the resection line in six patients who underwent robotic distal gastrectomy for clinical T1 gastric cancer. One to three days before surgery, ICG was diluted to 1.0 mg/mL, and 0.1 mL of this diluted ICG solution was endoscopically injected at one site into the submucosal layer of the stomach, 1 cm proximal to the tumor edge. Gastrectomy was performed using the da Vinci Xi surgical platform, equipped with a near-infrared fluorescence imaging system (Firefly®). The diameter of the fluorescent signal during gastrectomy was estimated to be approximately 2 cm. The resection line was determined on the outer edge of the fluorescent signal, which ensured a tumor-free margin of ≥2 cm. Fluorescent signals were successfully observed in all cases. Moreover, the required 2-cm surgical margin was achieved in all cases. DISCUSSION: We could successfully determine proximal margins using preoperative ICG injection marking during robotic distal gastrectomy for gastric cancer.

Drain Amylase Concentrations at 3 h After Gastrectomy Enhance Early Prediction of Postoperative Peripancreatic Inflammatory Fluid Collection.

BACKGROUND: Despite numerous studies of peripancreatic inflammatory fluid collection (PIFC) that report on the relevance of the drain amylase concentration (D-AMY), early prediction using this assay is problematic. This study aimed to investigate the clinical significance of measuring the D-AMY at 3 h after gastrectomy (POD0) for gastric cancer. METHODS: This retrospective analysis included consecutive patients who underwent gastrectomy combined with peripancreatic lymph node dissection. The predictive value of D-AMY on POD0 and postoperative day 1 (POD1) for clinically relevant PIFC was evaluated together or individually. RESULTS: Analyses were performed in 204 patients. Twenty (9.8%) patients experienced PIFC. D-AMY cutoffs of 721 IU/L on POD0 and 1695 IU/L on POD1 were determined using the receiver operating characteristic curve analysis for predicting PIFC. The D-AMY on POD0 had higher sensitivity (80%) but lower specificity (66.3%) for prediction of PIFC, compared with those of D-AMY on POD1 (65%, 89.1%, respectively). When combination marker analysis was performed, the highest risk group (D-AMY ≥ the cutoff values of POD0 and POD1) were associated with an elevated rate of occurrence (44%) and a high positive likelihood ratio (7.36) compared with those of the single cutoff group. The lowest risk group (D-AMY < the cutoff values on POD0 and POD1) was associated with a low rate of occurrence (2.5%) and low negative likelihood ratio (0.24) compared with those of the single cutoff group. CONCLUSIONS: Combined measurements of D-AMYs on POD0 and POD1 enhanced early prediction of PIFC after gastrectomy.

Prognostic impact of a microscopic positive margin in patients undergoing gastrectomy for gastric cancer: a propensity score­matched analysis of a multi­institutional dataset.

PURPOSE: We analyzed the effect of a microscopic positive margin on survival outcomes after gastrectomy for gastric cancer METHODS: We analyzed a multi-institutional dataset to study patients who underwent gastrectomy with curative intent between 2010 and 2014. We used propensity score matching to strictly balance the patients' oncological features, backgrounds, and postoperative treatment to compare the survival outcomes of those with microscopic positive margins and those with negative margins. RESULTS: Among 3029 patients, 32 (1.1%) had positive margins. After matching, we enrolled 128 patients in this retrospective analysis: 32 with a positive margin and 96 with a negative margin. The recurrence-free survival of the positive-margin group was significantly shorter than that of the negative-margin group (hazard ratio [HR], 1.62, 95% confidence interval, 1.00-2.63, p = 0.0485). Consistent results were observed for patients with pStages I-III disease (HR, 1.65, p = 0.0835), whereas the survival curves overlapped in those with pStage IV disease (HR, 1.29, p = 0.5934). The prevalence of overall recurrence in the positive-margin group was higher than that in the negative-margin group (75% vs 58%, p = 0.0917). This trend was consistent with locoregional recurrence (9% vs 3%) and distant recurrence (69% vs 55%). CONCLUSIONS: The survival of patients after curative gastrectomy for gastric cancer was worse in those with microscopic positive margins than in those with negative margins.

E-PASS scoring system serves as a predictor of short- and long-term outcomes in gastric cancer surgery.

PURPOSES: This study aimed to evaluate the estimation of the physiological ability and surgical stress (E-PASS) scoring system for predicting the short- and long-term outcomes in gastric cancer (GC) surgery. METHODS: We analyzed a multi-institutional dataset to study patients who underwent gastrectomy with a curative intent between 2010 and 2014. This study evaluated the associations between the optimal E-PASS score cutoff value and the following outcomes: (1) the incidence of postoperative complications in stage I-III GC patients and (2) the prognosis in stage II-III GC patients. RESULTS: A total of 2495 GC patients were included. A cutoff value of 0.419 was determined using the ROC curve analysis. Postoperative complications were observed more frequently in the E-PASS-high group than that in the E-PASS-low group (30% vs. 17%, p < 0.0001). Among pStage II-III GC patients (n = 1009), the overall survival time of the E-PASS-high group was significantly shorter than that of the E-PASS-low group (hazard ratio 2.08; 95% confidence interval 1.64-2.65; p < 0.0001). A forest plot revealed that E-PASS-high was associated with a greater prognostic factor for overall survival in most subgroups. CONCLUSIONS: The E-PASS scoring system may therefore be a useful predictor of the short- and long-term outcomes in patients with GC who have undergone radical gastrectomy.

SuP-Ring: A pneumatic tactile display with substitutional representation of contact force components using normal indentation.

BACKGROUND: Shear force is important for tumour detection and can contribute to minimally invasive surgery (MIS). A popular method uses lateral skin stretch to produce shear force but has some limitations. METHODS: We have developed a ring-type pneumatic tactile display that employs normal indentation substituted for lateral skin stretch to represent normal and shear feedback, called SuP-Ring. Psychophysical experiments were conducted to evaluate how users perceive the provided feedback and the effectiveness of SuP-Ring in tumour localisation. RESULTS: The experimental results show that the participants could perceive the provided normal and shear feedback well. Shear feedback enables users to enhance their performance in localising the tumour and normal feedback could contribute to ensuring the safety requirements in MIS. CONCLUSIONS: The proposed tactile display could be useful for intraoperative tumour localisation and has the potential to be used in a wide variety of applications.

Efficacy of Splenectomy for Proximal Gastric Cancer with Greater Curvature Invasion or Type 4 Tumor: a Propensity Score Analysis of a Multi-Institutional Dataset.

BACKGROUND: Splenectomy for proximal gastric cancer was found to have no survival benefit in a randomized trial clarifying the role of splenectomy (JCOG0110 study). However, since tumor with invasion to the greater curvature and Type 4 tumor were excluded in JCOG0110, the benefit of splenectomy for these tumors is not known. METHODS: A multicenter dataset of patients with gastric cancer who underwent gastrectomy between 2010 and 2014 was created. From the dataset, 114 eligible patients with proximal advanced gastric cancer with invasion to the greater curvature or Type 4 tumor were enrolled. There were 60 patients in the gastrectomy with splenectomy (Spx) group and 54 patients in the spleen-preserving (Prs) group. To balance the essential variables, propensity score analysis was performed, estimating the propensity score with a logistic regression model. Adjusted overall survival (OS) and adjusted disease-free survival (DFS) were estimated using the inverse probability of treatment weighting (IPTW) method. RESULTS: There were significant differences in age, performance status, comorbidity, macroscopic type, and clinical T stage between the Spx and Prs groups. The model for estimating the propensity score was well adapted (c-statistic: 0.830, 95%CI: 0.754-0.906). Adjusted OS was identical between the two groups (HR = 1.089, 95%CI: 0.759-1.563; p = 0.644). The DFS curve of Prs group was consistently tended to be lower than Spx, but the difference was not significant (HR = 0.813, 95%CI: 0.572-1.156; p = 0.249). CONCLUSIONS: The efficacy of splenectomy was minimal for proximal advanced gastric cancer even with invasion to the greater curvature or Type 4 tumor.

Accurate Prediction of Prognosis After Radical Resection of Gastric Cancer by the Modified Systemic Inflammation Score; a Multicenter Dataset Analysis.

BACKGROUND: The presence of chronic inflammation and nutritional status in cancer patients affects its prognosis. There is a clinical need for a prognostic predictor that is objective and accurate, and that can be easily evaluated by preoperative screening. We evaluated the importance and usefulness of the preoperative modified systemic inflammation score (mSIS) to predict the long-term outcome of patients undergoing curative resection for gastric cancer (GC). METHODS: Of the 3571 patients who underwent curative resection for GC in nine institutions between January 2010 and December 2014, 1764 patients who met the inclusion criteria were included. The mSIS was formulated according to the serum albumin level (ALB) and lymphocyte-to-monocyte ratio (LMR) as follows: mSIS 0 (ALB ≥ 4.0 g/dL and LMR ≥ 3.4), mSIS 1 (ALB < 4.0 g/dL or LMR < 3.4), and mSIS 2 (ALB < 4.0 g/dL and LMR < 3.4). RESULTS: Patients were categorized into preoperative mSIS 0 (n = 955), mSIS 1 (n = 584), and mSIS 2 (n = 225) groups. The overall survival times and the disease-free survival times of patients in preoperative mSIS 0,1 and 2 sequentially shortened (P < 0.0001), and mSIS 1 and 2 were identified as an independent prognostic factor (hazard ratio [HR] 1.35, 95% confidence interval [CI] 1.06-1.272, P = 0.0125 and HR 1.63, 95% CI 1.21-2.19, P = 0.0012). A stepwise increase in the prevalence of hematogenous recurrences was directly proportional to the mSIS. A forest plot revealed that mSIS 0,1 was associated with a greater risk of overall survival in most subgroups. CONCLUSION: Preoperative mSIS can be easily calculated, and it is suggested that it is useful as a prognostic predictor of patients with different disease stages, for stratifying and evaluating clinical outcomes.

A tactile sensor using the acoustic reflection principle for assessing the contact force component in laparoscopic tumor localization.

PURPOSE: Localization of an early stage gastric tumor is easily performed in conventional open surgery, whereas it is a difficult procedure in minimally invasive surgery (MIS). A tactile sensor could allow precise resection of the tumor in laparoscopic surgery. The safety of medical tools should be ensured in MIS. Moreover, boundary conditions such as a double-ended beam without a supporting rigid base during tissue palpation were hardly considered. Thus, we suppose that it is informative to assess the normal force and shear force for practical tumor detection considering the boundary condition. METHODS: In this study, a tactile sensor with normal and shear force measurement functions using the acoustic reflection principle was developed for gastric tumor detection in MIS. The developed tactile sensor was tested using an artificial phantom of the stomach without a supporting rigid base to evaluate the force response of the sensor in intraoperative tumor localization. RESULTS: The developed sensor is safe for human tissue and can be sterilized. The experimental results show that the developed tactile sensor has the capability to measure normal and shear forces. In the gastric tumor detection test, the shear force of the sensor was more stable and highly responsive to the tumor position than the normal force, which is greatly affected by the bending of the tissue during the operation. CONCLUSIONS: A two-axis tactile sensor using the acoustic reflection principle was assembled for tissue palpation in MIS. The results showed that the developed sensor is suitable for tumor detection, indicating that the shear force information of the developed sensor is more useful in MIS for early stage gastric tumor localization.

Randomised phase II trial of capecitabine plus oxaliplatin with continuous versus intermittent use of oxaliplatin as adjuvant chemotherapy for stage II/III colon cancer (CCOG-1302 study).

BACKGROUND: Peripheral sensory neuropathy (PSN) caused by oxaliplatin-based adjuvant chemotherapy adversely affects patients' quality of life. This study evaluated the efficacy and safety of capecitabine plus oxaliplatin (CAPOX) with intermittent oxaliplatin use compared with the standard CAPOX in adjuvant therapy for colon cancer. PATIENTS AND METHODS: Patients with curative resection for stage II/III colon cancer were randomly assigned to receive either CAPOX with continuous oxaliplatin (eight cycles of CAPOX) or CAPOX with intermittent oxaliplatin (two cycles of CAPOX, four cycles of capecitabine and two cycles of CAPOX). The primary end-point was the 1-year PSN rate, and the key secondary end-point was disease-free survival (DFS). RESULTS: Two hundred patients were enrolled in the intent-to-treat population. After 4 patients withdrew, 196 patients were included in the safety analysis. The overall treatment completion rate was 65% for continuous vs. 89% for intermittent treatment (p < 0.001). The 1-year PSN rate was 60% (95% confidence interval [CI], 50%-70%) for continuous and 16% (95% CI, 10%-25%) for intermittent treatment (p < 0.001). After a median follow-up of 52 months, 40 events (20%) were observed. The 3-year DFS was 81% (95% CI, 71%-87%) for continuous and 84% (95% CI, 75%-90%) for intermittent treatment (hazard ratio [HR], 0.87; 95% CI, 0.47-1.63). Among patients with high-risk disease (T4 or N2-3), the 3-year DFS was 57% for continuous vs. 74% for intermittent treatment (HR, 0.66). CONCLUSION: CAPOX with planned intermittent oxaliplatin may be feasible as an adjuvant therapy for colon cancer and substantially reduce the duration of long-lasting PSN. TRIAL IDENTIFIER: UMIN000012535.