Small gastric synovial sarcoma diagnosed and treatment by laparoscopic-endoscopic cooperative surgery: a case report.

We report a case of small gastric synovial sarcoma (SS) finally diagnosed after laparoscopic-endoscopic cooperative surgery (LECS). A 50 year-old male underwent medical examination for a chief complaint of epigastric pain. Endoscopic examination showed a 20 mm submucosal tumor (SMT) located in the anterior wall which extended to the lesser curvature of the middle stomach. The biopsy tissue did not yield a definitive diagnosis. During 6 months of follow-up for this lesion suspected to be an inflammatory tumor, neither the shape nor the size of the tumor changed. We performed LECS for both diagnosis and treatment. Histologically, the tumor was composed of fascicles of spindle cells. Immunohistochemically, the tumor cells were focally positive for epithelial membrane antigen, cytokeratin (AE1/AE3) and S100 protein, while being negative for desmin, α-smooth muscle actin, CD34, c-kit and DOG1. The expression of INI1 was reduced. Fluorescence in situ hybridization (FISH) detected SS18 rearrangement. The SMT was diagnosed as primary SS. A SMT measuring < 20 mm might be malignant potential tumor such as SS even if there are no typical malignant findings by endoscopy. Surgical resection should be considered for SMT measuring < 20 mm with atypical findings even in the absence of definitive high-risk features.

Hereditary Diffuse Gastric Cancer Treated by Prophylactic Total Gastrectomy.

We herein report a rare case of hereditary diffuse gastric cancer in a Japanese man. A 41-year-old man underwent esophagogastroduodenoscopy which revealed a small gastric erosion. Biopsy specimens showed signet ring cell carcinoma, and endoscopic submucosal dissection was performed. The patient's elder sister had died of gastric cancer at 38 years old. Considering the family history, a genetic test was conducted and revealed a CDH1 germline mutation. Although no carcinomatous lesion was detected endoscopically, prophylactic total gastrectomy was performed. The resection specimen showed seven microlesions of signet ring cell carcinoma confined to the lamina propria mucosae.

Buried bumper syndrome in percutaneous endoscopic gastrostomy with a jejunal extension tube in patients undergoing levodopa-carbidopa intestinal gel treatment.

BACKGROUND: Levodopa-carbidopa intestinal gel (LCIG) treatment is an effective Parkinson's disease (PD) treatment that requires percutaneous endoscopic gastrostomy with a jejunal extension tube (PEG-J). Buried bumper syndrome (BBS) is an uncommon but significant complication of PEG-J for LCIG. Case presentation A 71-year-old man had been undergoing LCIG therapy for PD since a PEG-J was implemented at our department two years previously. He presented with appetite loss. Computed tomography showed that the gastrostomy bumper was buried in the gastric wall. The patient was surgically treated with the simultaneous removal and replacement of PEG-J. Postoperative gastrocutaneous fistula occurred, which was conservatively treated. CONCLUSIONS: Notably, patients and medical staff should be aware that patients with PD on LCIG treatment have a high risk of BBS in PEG-J and that there might be some patients with latent BBS. When simultaneous removal and replacement surgery is performed, establishing a new route at the stomach and abdominal wall is recommended.

Segmental cervical esophagectomy with free jejunal flap reconstruction for cervical esophageal cancer in patients with previous history of gastric surgery: a report of two cases.

Although free-flap jejunal reconstruction is frequently performed after cervical esophagectomy for cervical esophageal cancer, the procedure after gastric surgery has not been reported. We encountered two patients with esophageal cancer and previous gastric surgeries who eventually underwent segmental esophagectomy with free-flap jejunal reconstruction. Case one involved a 75-year-old man who underwent abdominal abscess and duodenal ulcer perforation surgeries (abdominal drainage and subsequent gastrojejunal bypass). A type 0-IIa tumor was located posterior to the cervical esophagus's right wall, 21 cm from the incisor, without lymph node swelling or distant metastasis. The left lobe of the thyroid gland was mobilized to ensure an oral resection margin. Severe abdominal adhesions required careful adhesiolysis to harvest the jejunum (20 cm long) 40 cm from the jejunojejunostomy. An end-to-side and side-to-end esophagojejunostomy were performed for the proximal and distal ends, respectively. Case two involved a 75-year-old male with a history of distal gastrectomy with Billroth I reconstruction for early gastric cancer. A submucosal tumor-like lesion was located on the cervical esophageal wall on the left side, 21 cm from the incisor. The distal esophagus required additional segmental resection because the anal resection line was close to the tumor. Jejunum (10 cm long) 30 cm from Ligament of Treitz was harvested. An end-to-side and end-to-end esophagojejunostomy for the proximal and distal ends, respectively, was performed. This surgery requires a thorough preoperative examination to ensure an adequate surgical margin and a careful free-flap harvest based on post-gastric surgery anatomy.

Therapeutic strategy aiming at R0 resection for borderline-resectable esophageal squamous cell carcinoma using induction chemotherapy with docetaxel, cisplatin, and 5-fluorouracil.

OBJECTIVE: Treatment for borderline resectable (cT3br) esophageal squamous cell carcinoma (SCC) is currently undefined. This study aimed to analyze the outcome of treatment strategies including induction chemotherapy with docetaxel, cisplatin, and 5-fluorouracil (DCF) against T3br esophageal SCC. METHODS: A total of 32 patients with cT3br esophageal SCC enrolled in this study were treated with two cycles of DCF induction therapy. RESULTS: The overall response rate to DCF induction therapy was 62.5%, while the disease control rate was 93.8% (complete response (CR), three; partial response (PR), 17; stable disease (SD), 10; progressive disease (PD), 2). After DCF induction chemotherapy, 27 patients underwent conversion surgery (CS) and five patients underwent definitive chemoradiotherapy (CRT). Out of 27 patients who underwent CS, 17 underwent transthoracic esophagectomy and 10 underwent thoracoscopic esophagectomy. Anastomotic leakage occurred in five patients (18.5%) and pneumonia in four (14.8%). Recurrent laryngeal nerve paralysis and arrhythmia were observed in two patients (7.4%). The R0 resection rate was 81.5%. Among the five patients who underwent definitive CRT, only one patient (20.0%) achieved CR. Two patients (40.0%) had PR and two (40.0%) had PD. Salvage esophagectomy was performed in one patient after definitive CRT. The 1-, 3-, and 5-year overall survival rates were 75.0, 50.6, and 46.4%, respectively, whereas the 1-, 3-, and 5-year disease-free survival rates were 54.9, 38.8, and 38.8%, respectively. CONCLUSION: DCF induction therapy and subsequent CS or definitive CRT are promising treatment strategies for cT3br esophageal SCC.

Successful combined laparoscopic and thoracoscopic surgery for esophago-mediastinal fistulae.

Minimally invasive surgeries have been developed, not only for gastrointestinal cancer, but also for benign or emergency cases. We report the case of a 62-year-old male who underwent laparoscopic and thoracoscopic combined surgery for an esophago-mediastinal fistula caused by a press-through package. In the initial laparoscopic phase, transhiatal dissection of the lower thoracic esophagus and harvesting of the greater omentum were performed. In the thoracoscopic phase, resection of the fistula and esophageal wall closure were performed. Thereafter, the greater omentum was lifted via the esophageal hiatus and wrapped around the repaired part of the esophagus for reinforcement. The total operative time was 371 min, with 163 and 208 min for the laparoscopic and thoracoscopic phases, respectively. In total, 20 ml of blood was lost. No perioperative complications or recurrences were observed. Laparoscopic and thoracoscopic combined omentoplasty was effective for refractory esophago-mediastinal fistula.

Strategy Treatment of cT4b Esophageal Squamous Cell Carcinoma Using Docetaxel, Cisplatin, and 5-Fluorouracil.

BACKGROUND/AIM: This study analyzed the outcomes of docetaxel, cisplatin, and 5-fluorouracil (DCF) therapy and DCF plus concurrent radiotherapy (DCF-RT), both followed by conversion surgery, if possible, in patients with cT4b esophageal cancer. PATIENTS AND METHODS: Forty-six patients with cT4b esophageal cancer, including borderline cT4b lesions, were eligible. Borderline cT4b lesions were treated with induction DCF therapy. For definitive cT4b lesions, definitive DCF-RT was administered. Patients unsuitable for induction DCF therapy or DCF-RT were treated with other therapies. After treatment, conversion surgery (CS) was performed for the residual tumor in resectable cases. RESULTS: Induction DCF therapy was administered to 12 patients (group A), and DCF-RT was provided to 18 patients (group B). Meanwhile, other therapies were provided to 16 patients (group C). The 1-, 3-, and 5-year overall survival (OS) rates were 66.7, 30.0, and 15.0%, respectively, in group A; 66.7, 37.5, and 37.5%, respectively, in group B; and 62.5, 0, and 0%, respectively, in group C. DCF-RT tended to prolong survival, albeit without significance (p=0.1040). The group A + B had significantly better overall survival than group C (p=0.0437). Fourteen patients underwent CS (30.4%), and patients who underwent CS had significantly better overall survival than those who did not undergo surgery (p=0.0291). CONCLUSION: Induction DCF or DCF-RT is promising for the treatment of cT4b esophageal cancer. Effective CS including combined resection of the invaded organ can contribute to improved therapeutic outcomes.

Management of elderly patients with early gastric cancer in Japan.

Management of elderly patients with early gastric cancer is an important issue in an aging society such as Japan. While endoscopic resection is recommended as the standard treatment for early gastric cancers with extremely low risk of lymph node metastasis (<1%), gastrectomy with lymphadenectomy is recommended for the other early gastric cancers as the standard treatment even in elderly patients. Endoscopic submucosal dissection is the most recommended endoscopic resection procedure because of its high ability for 'en bloc' resection. Endoscopic submucosal dissection can reportedly provide favorable short-term outcomes in elderly patients. In terms of patient prognosis, the importance of considering patients' physical and nutritional conditions before endoscopic submucosal dissection has recently attracted attention. With respect to gastrectomy, the nationwide data in Japan have demonstrated relatively low 5-year overall survival and non-negligible post-operative 90-day mortality in men aged ≥75 years and women aged ≥80 years compared with those in younger patients. Among these elderly patients, 20% or more reportedly died within 5 years after gastrectomy mostly due to other diseases. These facts suggested the necessity of a less invasive management option for the elderly patients. Efforts are being made to provide a non-invasive follow-up option without gastrectomy following endoscopic resection in elderly patients. To avoid the increase in gastric cancer-related deaths, the selection of patients with relatively low lymph node metastasis risk is essential, and several tools to estimate the lymph node metastasis risk from early gastric cancers have been developed. To avoid overtreatment with gastrectomy in more elderly early gastric cancer patients, new endoscopic submucosal dissection indications for them are also warranted.

Dislocation of the gastric conduit reconstructed via the posterior mediastinal route is a significant risk factor for anastomotic disorder after McKeown esophagectomy.

BACKGROUND: Anastomotic disorder of the reconstructed gastric conduit is a life-threating morbidity after thoracic esophagectomy. Although there are various reasons for anastomotic disorder, the present study focused on dislocation of the gastric conduit (DGC). METHODS: The study cohort comprised 149 patients who underwent transthoracic esophagectomy. The relationships between DGC and peri- and postoperative morbidities were analyzed retrospectively. Data were analyzed to determine whether body mass index (BMI) and extension of the gastric conduit were related to DGC. Uni- and multivariate Cox regression analyses were performed to identify the factors associated with anastomotic disorder. RESULTS: DGC was significantly related to anastomotic leakage (P < .001), anastomotic stricture (P = .018), and mediastinal abscess/empyema (P = .031). Compared with the DGC-negative group, the DGC-positive group had a significantly larger mean preoperative BMI (23.01 ± 3.26 kg/m2 vs. 21.22 ± 3.13 kg/m2, P = .001) and mean maximum cross-sectional area of the gastric conduit (1024.75 ± 550.43 mm2 vs. 619.46 ± 263.70 mm2, P < .001). Multivariate analysis revealed that DGC was an independent risk factor for anastomotic leakage (odds ratio: 4.840, 95% confidence interval: 1.770-13.30, P < .001). Body weight recovery tended to be better in the DGC-negative group than in the DGC-positive group, although this intergroup difference was not significant. CONCLUSION: DGC reconstructed via the posterior mediastinal route is a significant cause of critical morbidities related to anastomosis. In particular, care is required when performing gastric conduit reconstruction via the posterior mediastinal route in patients with a high BMI.

The Prognostic Significance of Plakophilin-1 Expression in Esophageal Cancer.

BACKGROUND/AIM: Plakophilin 1 (PKP1) expression is inversely related to cancer grade. This study aimed to evaluate whether PKP1 is a prognostic marker for esophageal cancer (EC). MATERIALS AND METHODS: We tested immunohistochemically for PKP1 in squamous cell carcinoma EC specimens from 99 patients, including cytoplasmic (C), membrane (M), and nuclear (N) cellular areas, and analyzed their relationships with clinicopathological factors. RESULTS: PKP1stains were stratified into strong and weak for all three cellular areas. Staining was inversely related to tumor depth (C: p=0.002, M: p=0.00007, N: p=0.02), lymph node metastasis (C: p=0.003, M: p=0.001, N: p=0.004) and pathological stage (C: p=0.0004, M: p=0.0001, N: p=0.006). Cytoplasmic and membrane staining were inversely related to vessel invasion. Patients with strong C stain had a better overall survival than those with weak C stains (p=0.01). Disease-free survival of patients with strong M stains was better than that of those with weak staining (p=0.01). CONCLUSION: Cytoplasmic and membrane PKP1 expression is a possible prognostic marker for EC.

A Pilot Study Analyzing the Clinical Utility of Comprehensive Genomic Profiling Using Plasma Cell-Free DNA for Solid Tumor Patients in Japan (PROFILE Study).

BACKGROUND: The clinical utility of plasma cell-free DNA in precision cancer medicine has not been established. A pilot study was conducted to investigate the clinical utility of comprehensive genomic profiling by liquid biopsy in a Japanese population. METHODS: In this PROFILE study, 102 patients with advanced solid tumors who showed progression with standard systemic therapy underwent liquid biopsy between August 2017 and February 2020. Liquid biopsy was performed using Guardant360. RESULTS: Of the 102 patients, 56 were women, and the median age was 65 years. Regarding the types of cancer, 31 were hepatobiliary and pancreatic cancer, 17 were gastrointestinal cancer, and 13 were breast cancer. Frequently altered genes were TP53 (53.9%, 46/102), KRAS (25.5%, 26/102), PIK3CA (19.6%, 20/102), and EGFR (17.6%, 18/102). At least one genetic aberration was detected in 92 patients (90.2%). Actionable mutation was discovered in 88 patients (86.3%), and 67 patients (65.7%) were clinical trial candidates. Of the 102 patients, 22 (21.6%) were able to receive biomarker-matched therapy. Their best responses were as follows: 1 complete response, 3 partial responses, 7 stable diseases, and 11 progressive diseases. Additionally, the treated patients were divided on the basis of matching scores (≥ 50% vs. < 50%). The patients were divided into high and low groups. The high group had a higher disease control rate (DCR) of 75% compared with 20% in the low group (P = 0.010). CONCLUSIONS: The results indicate that liquid biopsy is useful for identifying actionable mutations associated with the clinical response of selected patients.

Intraoperative blood loss as an independent prognostic factor for curative resection after neoadjuvant chemotherapy for gastric cancer: a single-center retrospective cohort study.

PURPOSE: Surgery-induced factors such as postoperative infectious complications (PICs) and intraoperative blood loss (IBL) have a negative impact on the survival of patients undergoing surgery for gastric cancer. A recent study showed that neoadjuvant chemotherapy (NAC) could reduce the negative impact of PICs; hence, we conducted the present study to investigate if NAC can also reduce the negative prognostic impact of IBL. METHODS: We reviewed 115 gastric cancer patients treated with NAC and radical gastrectomy. The cut-off for IBL predicting the long-term survival was assessed by a receiver operating characteristic curve. The Cox proportional hazard model was used to evaluate the association between patient characteristics including IBL, overall survival, and disease-free survival. RESULTS: The cut-off for IBL was set at 990 ml. Twenty-six patients had excessive IBL exceeding 990 ml (22.6%) and PICs developed in 33 patients (28.7%). The body mass index, IBL, ypT, and ypN were significant independent prognostic predictors, but PICs were not. CONCLUSION: NAC did not decrease the risk induced by excessive IBL. The prophylactic effect of NAC on surgery-induced risk was inconsistent.

Histopathological evaluation of the effectiveness of oral Eppikajutsuto treatment for lymphatic malformation.

BACKGROUND: Lymphatic malformation (LM) is a congenital disease caused by lymphatic vessel malformation. Although standard therapies for LMs are sclerotherapy and/or surgical excision, a new therapy using Japanese herbal medicine Eppikajutsuto (TJ-28) has been recently reported as clinically effective. We aimed to experimentally confirm the therapeutic effectiveness of TJ-28 for LMs. METHODS: LM lesions were generated in the mesentery and peritoneum of mice by intraperitoneal injection of Freund's incomplete adjuvant. Mice with LMs were treated by gavage or dietary administration of TJ-28 for 2 months. Formalin-fixed paraffin-embedded tissue sections of mesentery and peritoneum tissues were histologically and immunohistochemically examined by focusing on lymph nodes and perinodal lymph vessels. RESULTS: Multiple Freund's incomplete adjuvant-associated foreign-body granulomas were formed in the mesentery and peritoneum, resulting in congestion of lymph fluid and dilatation of lymph vessels. The numbers and sizes of lymph nodes were not significantly different between TJ-28-treated and control groups. However, the luminal areas of lymphatic vessels were reduced significantly in the TJ-28 treatment group by both gavage and dietary administrations. CONCLUSION: TJ-28 conspicuously reduced congestion of lymph fluid. This is the first histopathological evaluation of LM model mice to study the effectiveness of oral TJ-28 treatment.

Neurophysiological biomarkers using transcranial magnetic stimulation in Alzheimer's disease and mild cognitive impairment: A systematic review and meta-analysis.

Transcranial magnetic stimulation (TMS) is a non-invasive neurophysiological tool that enables the investigation of cortical excitability in the human brain. Paired-pulse TMS paradigms include short- and long-interval intracortical inhibition (SICI/LICI), intracortical facilitation (ICF), and short-latency afferent inhibition (SAI), which can assess neurophysiological functions of GABAergic, glutamatergic, and cholinergic neural circuits, respectively. We conducted the first systematic review and meta-analysis to compare these TMS indices among patients with AD, mild cognitive impairment (MCI), and healthy controls (HC). Our meta-analyses indicated that RMT, SAI, SICI, and LICI were significantly lower in patients with AD, while ICF did not show a difference in patients with AD compared with HC. In patients with MCI, RMT and SAI were significantly lower than in HC. In conclusion, motor cortical excitability was increased, while cholinergic function was decreased in AD and MCI in comparison with HC and patients with AD had decreased GABAergic and glutamatergic functions compared with HC. Our results warrant further studies to differentiate AD, MCI, and HC, employing multimodal TMS neurophysiology.

Predictive value of the surgical Apgar score on postoperative complications in advanced gastric cancer patients treated with neoadjuvant chemotherapy followed by radical gastrectomy: a single-center retrospective study.

BACKGROUND: The surgical Apgar score (SAS) or modified SAS (mSAS) has been reported as a simple and easy risk assessment system for predicting postoperative complications in primary surgery for gastric cancer. However, few studies have described the SAS's utility in gastric surgery after neoadjuvant chemotherapy (NAC). METHODS: One hundred and fifteen patients who received NAC and radical gastrectomy from 2008 and 2015 were included in this study. The SAS was determined by the estimated blood loss (EBL), lowest intraoperative mean arterial pressure, and lowest heart rate. The mSAS was determined by the EBL reassessed using the interquartile values. The predictive values of the SAS/mSAS for postoperative complications were assessed with univariate and multiple logistic regression analyses. RESULTS: Among the 115 patients, 41 (35.7%) developed postoperative complications. According to analyses with receiver operating characteristic curves of the SAS and mSAS for predicting postoperative complications, the cut-off value of the mSAS was set at 8. The rates of anastomotic leakage, pancreatic fistula, and arrhythmia in patients with high mSAS (> 8) values were higher than in those with low (0-3) and moderate [1-4] mSAS values. A multiple logistic regression analysis showed that the operation time, body mass index, and diabetes mellitus were independent risk factors for postoperative complications. The mSAS was not a significant predictor. CONCLUSION: The predictive value of SAS or mSAS for morbidity may be limited in patients who undergo gastric cancer surgery after NAC. Future prospective studies with a large sample size will be needed to confirm the present results.

Long-term outcomes of preoperative docetaxel with cisplatin plus S-1 therapy for gastric cancer with extensive nodal metastasis (JCOG1002).

BACKGROUND: Preoperative chemotherapy with cisplatin plus S-1 (CS) followed by gastrectomy with D2 plus para-aortic lymph node (PAN) dissection is regarded as a standard treatment in Japan for advanced gastric cancer with bulky lymph node (BN) and/or PAN metastasis. In the JCOG1002, we added docetaxel to CS (DCS) to further improve long-term outcomes. However, the primary endpoint, clinical response rate (RR), did not reach the expected level (Ito et al. in Gastric Cancer 20:322-31, 2017). Herein, we report our long-term survival results. METHODS: Patients with BN and/or PAN metastasis received 2 or 3 cycles of DCS therapy (docetaxel at 40 mg/m2 and cisplatin at 60 mg/m2 on day 1 and S-1 at 80 mg/m2 per day for 2 weeks, followed by a 2-week rest) followed by gastrectomy with D2 plus PAN dissection and postoperative S-1 for 1 year. RESULTS: Between July 2011 and May 2013, 53 patients were enrolled. Clinically, 17.0% had both PAN and BN metastasis, and the rest had either PAN (26.4%) or BN (56.6%) metastasis. Among all eligible patients, the 5-year overall survival was 54.9% (95% confidence interval 40.3-67.3%) at the last follow-up in May 2018. Among 44 eligible patients with R0 resection, the 5-year relapse-free survival was 47.7% (95% confidence interval 32.5-61.5%). CONCLUSIONS: Adding docetaxel to CS in preoperative chemotherapy for extensive nodal metastasis improved neither short-term outcomes nor long-term survival. Preoperative chemotherapy with CS followed by D2 + PAN dissection and postoperative S-1 remains the standard of care for patients with extensive nodal metastasis.

Is surgery alone sufficient for treating T1 gastric cancer with extensive lymph node metastases?

BACKGROUND: Whether or not surgery alone is sufficient for treating patients with pathological stage T1N2M0 (Stage IIA), T1N3a/bM0 (Stage IIB/IIIB), and T3N0M0 (Stage IIA) gastric cancer who were not indicated for adjuvant treatment according to the Japanese gastric cancer treatment guideline remains unclear. METHODS: We retrospectively reviewed the clinical records of 236 patients who had been diagnosed with pT1N2-3b/pT3N0 gastric cancer and undergone R0 gastrectomy with lymph node dissection between January 2000 and December 2012 at the National Cancer Center Hospital, Japan. RESULTS: The 5-year recurrence-free survival (RFS) rates (95% confidence interval [CI]) of the patients with pathological (p) T1N2-3b and T3N0 cancer were 73.9% (63.1-84.7) and 89.5% (84.0-95.0), respectively. The only significant prognostic factors for the survival identified by a multivariate Cox regression analysis in patients with pT1N2-3 cancer were the pN stage (N3a/N2: hazard ratio [HR] 2.940, 95% CI 1.314-5.577; N3b/N2: HR 8.688, 95% CI 3.096-24.382) and tumor diameter (<30/ ≥ 30 mm) (HR 2.919; 95% CI 1.351-6.304). We divided the patients with pT1N2-3 gastric cancer into 3 risk categories (high, moderate, low) using these 2 significant prognostic factors and found that the 5-year RFS rates were significantly different among the 3 risk groups (low risk, 93.0%; moderate risk, 66.7%; high risk, 25.0%; P < 0.001). CONCLUSIONS: pT3N0 and large pT1N2 with a diameter ≥ 30 mm had an excellent prognosis, while pT1N2-3 with at least N3a/b or a tumor diameter < 30 mm showed a relatively poor prognosis. These patients may be candidates for adjuvant chemotherapy.

Different risks of nodal metastasis by tumor location in remnant gastric cancer after curative gastrectomy for gastric cancer.

BACKGROUND: Curative surgery for remnant gastric cancer (RGC) after gastrectomy for gastric cancer (GC) can be challenging. We examined the risk factors for lymph node metastasis in RGC, especially for tumors located at the greater curvature (G) or non-greater curvature (NG), to determine the appropriate indications of curative surgery. METHODS: Data from the two high-volume centers of Japan between 1998 and 2018 were retrospectively reviewed. Among the 137 patients enrolled in this study, 34 were classified as the G group and 103 as the NG group. The incidence of lymph node metastasis and its risk factors was evaluated. RESULTS: Lymph node metastasis was observed in 21.2% (29/137), including 38.2% (13/34) in the G group and 15.5% (16/103) in the NG group (p = 0.008). A logistic regression analysis showed that tumor location of G or NG (p = 0.042), tumor size (p = 0.002) and depth of invasion (p = 0.009) were significant independent risk factors for nodal metastasis. Risk classification using these factors showed that clinical T1-T2 with a maximum size < 35 mm located at the non-greater curvature had the lowest nodal metastatic risk (4.3%). CONCLUSIONS: Tumor location at the G or NG was a significant risk factor for nodal metastasis in RGC. When selecting curative surgery for RGC, physicians should consider the nodal metastatic risk calculated by the tumor location, size and depth of invasion.

Survival outcomes after laparoscopy-assisted distal gastrectomy versus open distal gastrectomy with nodal dissection for clinical stage IA or IB gastric cancer (JCOG0912): a multicentre, non-inferiority, phase 3 randomised controlled trial.

BACKGROUND: Laparoscopy-assisted distal gastrectomy (LADG) is increasingly being used as an alternative to open distal gastrectomy (ODG) for gastric cancer treatment. Retrospective studies have shown equivalent survival with the two procedures, but these studies are limited by selection bias because LADG is more technically difficult than ODG. We aimed to evaluate whether LADG was non-inferior to ODG in terms of long-term survival outcomes. METHODS: We did an open-label, multicentre, non-inferiority, phase 3 randomised controlled trial at 33 institutions in Japan. Patients aged 20-80 years with histologically confirmed gastric adenocarcinoma (T1N0, T1N1, or T2[MP]N0), clinical stage I, in the middle or lower third of the stomach, Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, with a body-mass index of less than 30 kg/m2, were randomly assigned (1:1) to receive ODG or LADG. Randomisation was done by telephone, fax, or with a web-based system in the Japan Clinical Oncology Group Data Center; a minimisation method with a random component was used to adjust for institution and clinical stage (IA or IB). Only study-accredited surgeons performed ODG and LADG. The primary endpoint was relapse-free survival and was analysed according to the intention-to-treat principle. The non-inferiority margin (LADG vs ODG) was set at a hazard ratio (HR) of 1·54. The trial was registered with the UMIN Clinical Trials Registry, UMIN000003319. FINDINGS: Between March 15, 2010, and Nov 29, 2013, 921 patients were enrolled and randomly assigned to receive ODG (n=459) or LADG (n=462). 912 (99%) participants had the assigned surgery. 5-year relapse-free survival was 94·0% (95% CI 91·4-95·9) in the ODG group and 95·1% (92·7-96·8) in the LADG group. LADG was non-inferior to ODG for relapse-free survival (HR 0·84 [90% CI 0·56-1·27]), p=0·0075). The most common grade 3 or 4 adverse event was bowel obstruction, occurring in 11 (2%) of 455 patients in the ODG group and five (1%) of 457 patients in the LADG group. There were no treatment-related deaths. INTERPRETATION: This trial supports the non-inferiority of LADG compared with ODG for clinical stage I gastric cancer relapse-free survival, suggesting that LADG should be considered a standard treatment option when performed by experienced surgeons. FUNDING: Japan National Cancer Center, Ministry of Health, Labour and Welfare of Japan, Japan Agency for Medical Research and Development.