Prognostic Impact of Post-operative Infectious Complications in Gastric Cancer Patients Receiving Neoadjuvant Chemotherapy: Post Hoc Analysis of a Randomized Controlled Trial, JCOG0501.

PURPOSE: Post-operative infectious complication (IC) is a well-known negative prognostic factor, while showing neoadjuvant chemotherapy (NAC) may cancel out the negative influence of IC. This analysis compared the clinical impacts of IC according to the presence or absence of NAC in gastric cancer patients enrolled in the phase III clinical trial (JCOG0501) which compared upfront surgery (arm A) and NAC followed by surgery (arm B) in type 4 and large type 3 gastric cancer. METHODS: The subjects were 224 patients who underwent R0 resection out of 316 patients enrolled in JCOG0501. The prognoses of the patients with or without ICs in each arm were investigated by univariable and multivariable Cox regression analyses. RESULTS: There were 21 (20.0%) IC occurrences in arm A and 15 (12.6%) in arm B. In arm A, the overall survival (OS) of patients with ICs was slightly worse than those without IC (3-year OS, 57.1% in patients with ICs, 79.8% in those without ICs; adjusted hazard ratio (95% confidence interval), 1.292 (0.655-2.546)). In arm B, patients with ICs showed a trend of better survival than those without ICs (3-year OS, 80.0% in patients with IC, 74.0% in those without IC; adjusted hazard ratio, 0.573 (0.226-1.456)). CONCLUSION: This study could not indicate the negative prognostic influence of ICs in gastric cancer patients receiving NAC, which might be canceled by NAC. To build exact evidence, further investigation with prospective and large numbers of data might be expected.

A multi-center, prospective, clinical study to evaluate the anti-reflux efficacy of laparoscopic double-flap technique (lD-FLAP Study).

Background: Double-flap technique (DFT) is a reconstruction procedure after proximal gastrectomy (PG). We previously reported a multi-center, retrospective study in which the incidence of reflux esophagitis (RE) (Los Angeles Classification ≥Grade B [LA-B]) 1 year after surgery was 6.0%. There have been many reports, but all of them were retrospective. Thus, a multi-center, prospective study was conducted. Methods: Laparoscopic PG + DFT was performed for cT1N0 upper gastric cancer patients. The primary endpoint was the incidence of RE (≥LA-B) 1 year after surgery. The planned sample size was 40, based on an estimated incidence of 6.0% and an upper threshold of 20%. Results: Forty patients were recruited, and 39, excluding one with conversion to total gastrectomy, received protocol treatment. Anastomotic leakage (Clavien-Dindo ≥Grade III) was observed in one patient (2.6%). In 38 patients, excluding one case of postoperative mortality, RE (≥LA-B) was observed in two patients (5.3%) 1 year after surgery, and the upper limit of the 95% confidence interval was 17.3%, lower than the 20% threshold. Anastomotic stricture requiring dilatation was observed in two patients (5.3%). One year after surgery, body weight change was 88.9 ± 7.0%, and PNI <40 and CONUT ≥5, indicating malnutrition, were observed in only one patient (2.6%) each. In the quality of life survey using the PGSAS-45 questionnaire, the esophageal reflux subscale score was 1.4 ± 0.6, significantly better than the public data (2.0 ± 1.0; p = 0.001). Conclusion: Laparoscopic DFT showed anti-reflux efficacy. Taken together with the acceptable incidence of anastomotic stricture, DFT can be an option for reconstruction procedure after PG.

5-year follow-up results of a JCOG1104 (OPAS-1) phase III non-inferiority trial to compare 4 courses and 8 courses of S-1 adjuvant chemotherapy for pathological stage II gastric cancer.

BACKGROUND: Postoperative adjuvant chemotherapy with S-1 for 1 year (corresponding to eight courses) is the standard treatment for pathological stage II gastric cancer. The phase III trial (JCOG1104) investigating the non-inferiority of four courses of S-1 to eight courses was terminated due to futility at the first interim analysis. To confirm the primary results, we reported the results after a 5-years follow-up in JCOG1104. METHODS: Patients histologically diagnosed with stage II gastric cancer after radical gastrectomy were randomly assigned to receive S-1 for eight or four courses. In detail, 80 mg/m2/day S-1 was administered for 4 weeks followed by a 2-week rest as a single course. RESULTS: Between February 16, 2012, and March 19, 2017, 590 patients were enrolled and randomly assigned to 8-course (295 patients) and 4-course (295 patients) regimens. After a 5-years follow-up, the relapse-free survival at 3 years was 92.2% for the 8-course arm and 90.1% for the 4-course arm, and that at 5 years was 87.7% for the 8-course arm and 85.6% for the 4-course arm (hazard ratio 1.265, 95% CI 0.846-1.892). The overall survival at 3 years was 94.9% for the 8-course arm, 93.2% for the 4-course arm, and that at 5 years was 89.7% for the 8-course arm, and 88.6% for the 4-course arm (HR 1.121, 95% CI 0.719-1.749). CONCLUSIONS: The survival of the four-course arm was slightly but consistently inferior to that of the eight-course arm. Eight-course S-1 should thus remain the standard adjuvant chemotherapy for pathological stage II gastric cancer.

Desmoid tumor occurrence following gastric cancer surgery: A report of two cases.

INTRODUCTION AND IMPORTANCE: While rare, desmoid tumors can develop after abdominal surgery and are difficult to differentiate from recurrent tumors following cancer resection. In this report, we describe two cases of desmoid tumors that occurred following gastric cancer procedures and were successfully treated with surgical resection. CASE PRESENTATION: In Case 1, a 77-year-old woman underwent open distal gastrectomy for gastric cancer followed by Roux-en-Y reconstruction. The pathological diagnosis was stage IIB T3N1M0 disease. Four years postsurgically, computed tomography (CT) revealed a 2.4 cm tumor lesion in the upper abdomen. Desmoid tumor was the most suspected tumor, for which a resection with partial resection of the jejunum was performed. In case 2, a 60-year-old man underwent open distal gastrectomy for gastric cancer and Billroth I reconstruction; the pathological diagnosis was T1aN0M0 stage IA. Two years later, CT revealed a 4.0 cm tumor lesion in the upper abdomen. As in Case 1, desmoid tumor was most suspected, a tumor resection with partial resection of the jejunum was performed. Based on the pathological findings, the tumors were diagnosed as desmoid tumor. There had been no recurrence of either gastric cancer or the desmoid tumor in both cases. CLINICAL DISCUSSION: Although active surveillance has been recommended for desmoid tumors recently, surgical resection is appropriate when recurrence cannot be ruled out. CONCLUSIONS: Desmoid tumors should be included in the differential diagnosis when intra-abdominal tumors occur after surgery for gastric cancer. Complete resection with adequate margins can prevent desmoid recurrence.

Prognostic nutritional index is a prognostic factor for patients with gastric cancer and esophagogastric junction cancer undergoing proximal gastrectomy with esophagogastrostomy by the double-flap technique: A secondary analysis of the rD-FLAP study.

PURPOSE: Although proximal gastrectomy (PG) is commonly used in patients with upper gastric cancer (GC) and esophagogastric junction (EGJ) cancer, long-term prognostic factors in these patients are poorly understood. The double-flap technique (DFT) is an esophagogastrostomy with anti-reflux mechanism after PG; we previously conducted a multicenter retrospective study (rD-FLAP) to evaluate the short-term outcomes of DFT reconstruction. Here, we evaluated the long-term prognostic factors in patients with upper GC and EGJ cancer. METHODS: The study was conducted as a secondary analysis of the rD-FLAP Study, which enrolled patients who underwent PG with DFT reconstruction, irrespective of disease type, between January 1996 and December 2015. RESULTS: A total of 509 GC and EGJ cancer patients were enrolled. Univariate and multivariate analyses of overall survival demonstrated that a preoperative prognostic nutritional index (PNI) < 45 (p < 0.001, hazard ratio [HR]: 3.59, 95% confidential interval [CI]: 1.93-6.67) was an independent poor prognostic factor alongside pathological T factor ([pT] ≥2) (p = 0.010, HR: 2.29, 95% CI: 1.22-4.30) and pathological N factor ([pN] ≥1) (p = 0.001, HR: 3.27, 95% CI: 1.66-6.46). In patients with preoperative PNI ≥45, PNI change (<90%) at 1-year follow-up (p = 0.019, HR: 2.54, 95%CI: 1.16-5.54) was an independent poor prognostic factor, for which operation time (≥300 min) and blood loss (≥200 mL) were independent risk factors. No independent prognostic factors were identified in patients with preoperative PNI <45. CONCLUSIONS: PNI is a prognostic factor in upper GC and EGJ cancer patients. Preoperative nutritional enhancement and postoperative nutritional maintenance are important for prognostic improvement in these patients.

Identifying Risk Factors of Complications following Total Gastrectomy for Gastric Cancer: Comparison between Splenectomy and Spleen-Preserving Surgery - A Supplementary Analysis of JCOG0110.

INTRODUCTION: Splenectomy for proximal gastric cancer was found to offer no survival benefit in a randomized trial clarifying the role of splenectomy (JCOG0110 study). Although many studies have explored risk factors for morbidities following total gastrectomy, none have assessed the risk factors for postoperative complications in spleen-preserving total gastrectomy. METHODS: Using data from 505 patients enrolled in a previous randomized trial, risk factors for postoperative complications were identified by multivariable logistic regression analysis. Then, the risk factors were assessed separately between splenectomy and spleen-preserving total gastrectomy. RESULTS: Postoperative complications were identified in 119 patients (23.6%) and were more common following splenectomy than following spleen-preserving surgery (30.7% and 16.1%, respectively, p < 0.01). Multivariable analysis revealed that age ≥65 years (p = 0.032), body mass index ≥25 (p = 0.003), and blood loss ≥350 (p = 0.019) were independent risk factors for postoperative complications in the entire cohort. Among them, only body mass index was a significant independent risk factor for complications in both spleen preservation (p = 0.047) and splenectomy groups (p = 0.017). CONCLUSION: Risk factors for postoperative complications were essentially the same between splenectomy and spleen preservation. Being overweight increased the risk of postoperative complications.

Surgical resection of a retroperitoneal liposarcoma producing insulin-like growth factor II: a case report.

BACKGROUND: Tumor-produced high molecular weight insulin-like growth factor-II (big insulin-like growth factor-II) is considered to cause non-islet cell tumor hypoglycemia. This paper presents a case of surgically resected retroperitoneal liposarcoma that produced big insulin-like growth factor-II. CASE PRESENTATION: Here, we report the case of a 62-year-old woman who presented with an abdominal mass and hypoglycemia. Non-islet cell tumor hypoglycemia due to retroperitoneal liposarcoma was suspected. After complete resection of the tumor, the patient's hypoglycemia improved and big insulin-like growth factor-II disappeared in the molecular weight analysis of serum insulin-like growth factor-II by western blotting. The patient had no tumor recurrence or reappearance of hypoglycemia 16 months after the operation without any adjuvant therapy. CONCLUSIONS: Although insulin-like growth factor-II-producing tumors are generally large and difficult to operate on, surgical resection is currently the most effective and only treatment; thus, it is essential to attempt resection aggressively.

Incidence of Metachronous Remnant Gastric Cancer after Proximal Gastrectomy with the Double-flap Technique (rD-FLAP-rGC Study): A Multicenter, Retrospective Study.

BACKGROUND: Although proximal gastrectomy (PG) with the double-flap technique (DFT) is a function-preserving surgery that prevents esophagogastric reflux, there is a risk of developing metachronous remnant gastric cancer (MRGC). Moreover, details of MRGC and appropriate postoperative follow-up after PG with DFT are unclear. METHODS: We reviewed the medical records of 471 patients who underwent PG with DFT for cancer in a preceding, multicenter, retrospective study (rD-FLAP Study). We investigated the incidence of MRGC, frequency of follow-up endoscopy, and eradication of Helicobacter pylori (H. pylori) infection. RESULTS: MRGC was diagnosed in 42 (8.9%) of the 471 patients, and 56 lesions of MRGC were observed. The cumulative 5- and 10-year incidence rates were 5.7 and 11.4%, respectively. There was no clinicopathological difference at the time of primary PG between patients with and without MRGC. Curative resection for MRGC was performed for 49 (88%) lesions. All patients with a 1-year, follow-up, endoscopy interval were diagnosed with early-stage MRGC, and none of them died due to MRGC. Overall and disease-specific survival rates did not significantly differ between patients with and without MRGC. The incidence rate of MRGC in the eradicated group after PG was 10.8% and that in the uneradicated group was 19.6%, which was significantly higher than that in patients without H. pylori infection at primary PG (7.6%) (p = 0.049). CONCLUSIONS: The incidence rate of MRGC after PG with DFT was 8.9%. Early detection of MRGC with annual endoscopy provides survival benefits. Eradicating H. pylori infection can reduce the incidence of MRGC.

Late complication after gastrectomy for clinical stage I cancer: supplementary analysis of JCOG0912.

BACKGROUND: Late complications following gastric cancer surgery, including postgastrectomy syndromes, are complex problems requiring a solution. Reported risk factors for developing late complications include surgery-related factors, such as the surgical approach and the extent of resection and reconstruction. However, this has not been assessed in a prospective study with a large sample size. Therefore, this study aimed to evaluate associations between surgery-related factors and the development of late complications. Data from the JCOG0912 trial were used. It compared laparoscopy-assisted distal gastrectomy (LADG) to open distal gastrectomy (ODG) in clinical stage I gastric cancer patients. METHODS: This study included 881/921 patients enrolled in the JCOG0912 trial. The incidence of late complications was compared between the ODG and the LADG arms. In addition, associations between surgery-related factors and the development of late complications were assessed by multivariable analyses using the proportional odds model to identify relevant risk factors. RESULTS: There was no difference in the type or number of patients with late complications between the LADG and the ODG arms. The multivariable analysis for each late complication revealed that the Billroth-I reconstruction (vs. R-en-Y or Billroth-II) had a lower risk of cholecystitis [odds ratio (OR) 0.187, 95% confidence interval (CI) 0.039-0.905, P = 0.037] or ileus (OR 0.116, 95%CI 0.033-0.406, P < 0.001), and pylorus-preserving gastrectomy (vs. R-en-Y or Billroth-II) had a higher risk of reflux esophagitis (OR 3.348, 95% CI 1.371-8.176, P = 0.008). The surgical approach was not a risk factor for any late complications. CONCLUSION: Differences in surgical approaches did not constitute a risk for developing late complications after gastrectomy. Billroth-I reconstruction reduced the risk of ileus and cholecystitis, but pylorus-preserving gastrectomy carried a risk for reflux esophagitis.

'The parachute method': A novel technique for laparoscopic tumour handling.

Aims and Objectives: Although laparoscopic surgery for submucosal tumours (SMTs) may require multiple support threads, the traction direction of a single thread is only one option and cannot be freely changed. To solve this problem, we introduced a novel innovative technique for tumour handling, named 'the parachute method'. Subjects and Methods: Prior to suturing, the surrounding vessel was treated when the tumour was located near the lesser or greater curvature. A monofilament thread was ligated in the serous muscle layer along the peritumoural markings with approximately five stitches in a row, with moderate deflection. Next, the other monofilament thread was passed through the deflection and ligated; this resembled a parachute shape that could be pulled in any direction over the entire circumference with uniform tension. Results: We performed this procedure in three patients with extramural growth-type gastrointestinal stromal tumours of approximately 2-3 cm. The median suturing time was 10 minutes. Laparoscopic local resection of the stomach was safely performed, and the patients were discharged without any complications. Conclusion: In this study, we demonstrate a novel, simple, inexpensive, useful and reasonable technique for handling SMTs, named 'the parachute method'. We believe that this technique will have additional applications in cooperative surgery with endoscopy.

Machine learning for classification of postoperative patient status using standardized medical data.

BACKGROUND AND OBJECTIVE: Real-world evidence is defined as clinical evidence regarding the use and potential benefits or risks of a medical product derived from real-world data analyses. Standardization and structuring of data are necessary to analyze medical real-world data collected from different medical institutions. An electronic message and repository have been developed to link electronic medical records in this research project, which has simplified the data integration. Therefore, this paper proposes an analysis method and learning health systems to determine the priority of clinical intervention by clustering and visualizing time-series and prioritizing patient outcomes and status during hospitalization. METHODS: Common data items for reimbursement (Diagnosis Procedure Combination [DPC]) and clinical pathway data were examined in this project at each participating institution that runs the verification test. Long-term hospitalization data were analyzed using the data stored in the cloud platform of the institutions' repositories using multiple machine learning methods for classification, visualization, and interpretation. RESULTS: The ePath platform contributed to integrate the standardized data from multiple institutions. The distribution of DPC items or variances could be confirmed by clustering, temporal tendency through the directed graph, and extracting variables that contributed to the prediction and evaluation of SHapley Additive Explanation effects. Constipation was determined to be the risk factor most strongly related to long-term hospitalization. Drainage management was identified as a factor that can improve long-term hospitalization. These analyses effectively extracted patient status to provide feedback to the learning health system. CONCLUSIONS: We successfully generated evidence of medical processes by gathering patient status, medical purposes, and patient outcomes with high data quality from multiple institutions, which were difficult with conventional electronic medical records. Regarding the significant analysis results, the learning health system will be used on this project to provide feedback to each institution, operate it for a certain period, and analyze and re-evaluate it.

Severe reflux esophagitis after total gastrectomy successfully treated by transposition of the jejunojejunal anastomosis: a report of two cases.

BACKGROUND: Reflux esophagitis after total gastrectomy is often difficult to treat. In this report, we describe two cases of reflux esophagitis that were refractory to medical therapy and successfully treated by transposition of the jejunojejunal anastomosis. CASE PRESENTATION: Case 1: A 66-year-old man underwent total gastrectomy and cholecystectomy for gastric cancer, and Roux-en-Y (RY) reconstruction was performed. The pathological diagnosis was T4aN3aM0 stage IIIC. Five months later, esophagogastroduodenoscopy identified reflux esophagitis. Although he was treated with various oral medications and was hospitalized six times, he lost 19 kg of weight. Finally, the patient was reoperated 3 years postoperatively. Intraoperative findings showed that there was no evidence of recurrence or severe adhesions that could have caused obstruction, and the anastomotic distance between the esophagojejunostomy and the jejunojejunostomy was approximately 40 cm. The jejunojejunostomy was re-anastomosed to increase the distance to 100 cm. Two years and 6 months after the reoperation, there was no recurrence of reflux esophagitis, and the patient's weight increased by 14 kg. Case 2: A 68-year-old woman underwent total gastrectomy and cholecystectomy for gastric cancer, and RY reconstruction was performed. The pathological diagnosis was T4aN0M0 stage IIB. Similar to Case 1, the patient was diagnosed with reflux esophagitis 5 months later. She lost 23 kg of weight and was reoperated at 6 months postoperatively. Intraoperative findings showed that there was no evidence of recurrence or severe adhesions, and transposition of the jejunojejunostomy was performed to increase the distance between anastomoses from 40 to 100 cm. Two years and 8 months after the reoperation, there was no recurrence of reflux esophagitis, and her weight increased by 15 kg. CONCLUSIONS: Transposition of the jejunojejunostomy was an effective treatment for medication-resistant severe reflux esophagitis after total gastrectomy.

Impact of postoperative complications on survival outcomes in patients with gastric cancer: exploratory analysis of a randomized controlled JCOG1001 trial.

BACKGROUND: Recent studies have found a negative impact of postoperative complications on long-term survival outcomes, but it has not been confirmed by data obtained from a prospective study with a large sample size. This study investigated the impact of postoperative complications on long-term survival outcomes, and considered the optimal definition of complication, using data from JCOG1001, which compared bursectomy and non-bursectomy for patients with cT3/4a locally advanced gastric cancer. METHODS: This study included 1191 of 1204 patients enrolled in the JCOG1001 trial. Complications were graded by Clavien-Dindo (C-D) classification. Impact of the grade (≥ C-D grade II or ≥ grade III) or type (any or intra-abdominal infectious) of complication on survival outcome was evaluated by univariate and multivariable analyses using the Cox proportional hazard model. RESULTS: The incidence of any ≥ C-D grade II and ≥ grade III complication was 23.0% and 9.7%, respectively, and that of ≥ grade II and ≥ grade III intra-abdominal infectious complication was 13.4% and 6.9%, respectively. Multivariable analysis showed all four definitions of complications were independent prognostic factors for overall survival. Conversely, only any ≥ C-D grade III complication was found to be an independent prognostic factor for relapse-free survival (hazard ratio, 1.445; 95% confidence interval, 1.026-2.036; P = 0.035). CONCLUSIONS: Postoperative complications adversely affect the long-term survival outcomes of patients with cT3/4a gastric cancer. Any ≥ C-D grade III complication seems to be the most suitable definition of complication for predicting negative long-term survival outcomes.

Rare squamous cell carcinoma arising from a presacral epidermoid cyst: A case report.

INTRODUCTION: Presacral epidermoid cysts are uncommon, usually benign cysts caused by developmental abnormalities in the fetal period. We present a rare case of squamous cell carcinoma arising from a presacral epidermoid cyst. PRESENTATION OF CASE: A 59-year-old woman complained of tenesmus and discomfort in the buttocks. Computed tomography revealed a 50-mm well-defined cystic mass in the presacrum and a 70-mm solid mass extending from the cyst into the rectum, vagina, and left sciatic spine. On T1-weighted magnetic resonance images, the cyst was unilocular and the mass was marginated with low intensity. On T2-weighted images, the mass had high intensity. A malignant presacral developmental cyst was diagnosed, without obvious metastasis. Using abdominal and parasacral approaches, Hartmann's operation was performed with multiorgan resection, including the sacrum, coccyx, left sciatic spine, internal obturator muscle, rectum, and uterine appendage. Histopathology of the excised specimen revealed a squamous cell carcinoma originating from the presacral epidermoid cyst. DISCUSSION: Reports of malignant transformation of epidermoid cysts in the presacral space, as in the present case, are extremely rare. Because of their unusual location and slow growth, epidermoid cysts tend to remain asymptomatic. Because the patient had a malignant tumor with suspected invasion of adjacent organs, combination surgery was selected. CONCLUSION: Although further research is required, presacral epidermoid cysts are extremely rare and may be malignant. Thorough preoperative image evaluation is crucial for complete resection.

Multicenter retrospective study to evaluate the efficacy and safety of the double-flap technique as antireflux esophagogastrostomy after proximal gastrectomy (rD-FLAP Study).

AIM: As a result of the difficulty in effective prevention of gastroesophageal reflux, no standard reconstruction procedure after proximal gastrectomy (PG) has yet been established. The double-flap technique (DFT), or Kamikawa procedure, is an antireflux reconstruction procedure in esophagogastrostomy. The efficacy of DFT has recently been reported in several studies. However, these were all single-center studies with a limited number of cases. METHODS: We conducted a multicenter retrospective study in which patients who underwent DFT, irrespective of disease type and reconstruction approach, at each participating institution between 1996 and 2015 were registered. Primary endpoint was incidence of reflux esophagitis at 1-year after surgery, and secondary endpoint was incidence of anastomosis-related complications. RESULTS: Of 546 patients who were eligible for this study, 464 patients who had endoscopic examination at 1-year follow up were evaluated for reflux esophagitis. Incidence of reflux esophagitis of all grades was 10.6% and that of grade B or higher was 6.0%. Male gender and anastomosis located in the mediastinum/intra-thorax were independent risk factors for grade B or higher reflux esophagitis (odds ratio [OR]: 4.21, 95% confidence interval [CI]: 1.44-10.9, P = 0.0109). Total incidence of anastomosis-related complications was 7.2%, including leakage in 1.5%, strictures in 5.5% and bleeding in 0.6% of cases. Laparoscopic reconstruction was the only independent risk factor for anastomosis-related complications (OR: 3.93, 95% CI: 1.93-7.80, P = 0.0003). CONCLUSION: Double-flap technique might be a feasible option after PG for effective prevention of reflux, although anastomotic stricture is a complication that must be well-prepared for.

Four courses versus eight courses of adjuvant S-1 for patients with stage II gastric cancer (JCOG1104 [OPAS-1]): an open-label, phase 3, non-inferiority, randomised trial.

BACKGROUND: Postoperative adjuvant chemotherapy with S-1 for 1 year (corresponding to eight courses) is standard care for stage II gastric cancer. Whether the duration of S-1 could be shortened to 6 months (corresponding to four courses) without worsening survival is unclear. The aim of this study was to investigate the non-inferiority of four courses of S-1 compared with eight courses of S-1 for patients with stage II gastric cancer. METHODS: We did a phase 3, open-label, randomised controlled, non-inferiority trial at 59 hospitals in Japan. Patients aged 20-80 years with stage II adenocarcinoma of the stomach were randomly assigned (1:1) to eight courses or four courses of S-1. Randomisation was done by the Japan Clinical Oncology Group Data Center website, using a minimisation method with a random component using institution, stage (IIA vs IIB), age (<70 years vs ≥70 years), and mode of operation (open gastrectomy with bursectomy vs open gastrectomy without bursectomy vs laparoscopic gastrectomy) as adjustment factors. One course was 80 mg/day per m2 of S-1 administered for 4 weeks followed by a rest for 2 weeks. The primary endpoint was relapse-free survival, analysed by intention to treat, with a non-inferiority margin for the hazard ratio (HR) set at 1·37. This study is registered at UMIN-Clinical Trial Registry, number UMIN000007306. FINDINGS: Between Feb 16, 2012, and March 19, 2017, 590 patients were enrolled (295 per group). 528 (89%) patients were analysed at the first planned interim analysis in March, 2017, at which time the point estimate of HR for the four-course group compared with the eight-course group was 2·52 (95% CI 1·11-5·77), which exceeded 1·37 and met the prespecified criteria for early termination. Predictive probability for showing non-inferiority at the final analysis was calculated to be 2·9%. The study was stopped for futility. Updated 3-year relapse-free survival analysed in May, 2017, was 93·1% (95% CI 87·8-96·1) for the eight-course group and 89·8% (84·2-93·5) for the four-course group (HR 1·84, 95% CI 0·93-3·63). The most common grade 3-4 adverse event was neutropenia, observed in 46 (16%) patients in the eight-course group and 51 (17%) patients in the four-course group. INTERPRETATION: S-1 for 1 year should remain as standard adjuvant chemotherapy for stage II gastric cancer. FUNDING: Japan Agency for Medical Research and Development; the Ministry of Health, Labour and Welfare of Japan; the National Cancer Center Research and Development Fund, Japan.

Validation of an assessment tool: Estimation of Postoperative Overall Survival for Gastric Cancer.

BACKGROUND: Benchmarking of long-term surgical outcomes has rarely been attempted. We previously devised a prediction model for assessing the outcome of late survival after surgery, termed the Estimation of Postoperative Overall Survival for Gastric Cancer (EPOS-GC). This study was undertaken to validate EPOS-GC in an external data set. METHODS: A retrospective cohort study was conducted in 11 cancer care hospitals in Japan, analyzing a consecutive series of patients who underwent elective gastric cancer resection between April 2007 and March 2009. EPOS-GC consists of three tumor-related variables and three physiological variables. The primary endpoint was postoperative overall survival. The observed-to-expected (O/E) ratio of 5-year survival rates was defined as a metric of quality of care. The sample size for O/E was determined as 42. RESULTS: We included 2045 patients for analysis. The median (95% confidence interval) follow-up time was 5.1 (1.2-6.8) years for censored patients. Although EPOS-GC demonstrated a good discriminative power (Harrell's C-index, 95% confidence interval: 0.80, 0.79-0.83), the calibration plot revealed that EPOS-GC underestimated 5-year survival rates in the high-risk group. Therefore, we recalibrated the model with Cox's regression analysis. The recalibrated EPOS-GC showed a good calibration, preserving the high discriminative power (C-index, 95% confidence interval: 0.80, 0.78-0.82). The O/E among hospitals according to the recalibrated EPOS-GC ranged between 0.87 and 1.27. The O/E correlated with hospital volumes (Spearman's correlation = 0.76, n = 11, p = .006). CONCLUSION: EPOS-GC with recalibration can convey risk-adjusted quality assurance regarding late survival following gastric cancer resection.

Feasibility of oral administration of S-1 as adjuvant chemotherapy in gastric cancer: 4-week S-1 administration followed by 2-week rest vs. 2-week administration followed by 1-week rest.

In 2006, the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer (ACTS-GC) demonstrated that S-1 is an effective adjuvant therapy for gastric cancer. Following that study, S-1 has been used as the standard adjuvant therapy for gastric cancer in Japan. However, the 1-year completion rate was only 65.8% in the ACTS-GC study and feasibility remains a critical issue. We conducted a study to evaluate the feasibility of 2 weekly administration regimens of S-1 as adjuvant chemotherapy in gastric cancer. The criteria for eligibility included histologically proven stage II (excluding T1), IIIA or IIIB gastric cancer with D2 lymph-node dissection. The patients were randomly assigned to either arm A (S-1 administration for 4 weeks followed by 2 weeks of rest) or arm B (S-1 administration for 2 weeks followed by 1 week of rest). In each arm, treatment was continued for 12 months unless recurrence or severe adverse events were observed. The primary endpoint was feasibility (protocol treatment completion rate). The secondary endpoints were safety, relapse-free survival and overall survival. A total of 47 patients were assigned to arms A or B between May, 2008 and February, 2010. During the first interim analysis, the protocol treatment completion rates in arms A and B were 83 and 100%, respectively at 6 months and 49 and 89%, respectively, at 12 months (P=0.0046). Therefore, S-1 administration for 2 weeks followed by 1 week rest was more feasible as adjuvant chemotherapy in gastric cancer. Grade 3 adverse events in arm A included fatigue (8.0%), anorexia (8.0%), nausea (4.0%), vomiting (4.0%) and hand-foot syndrome (4.0%), whereas none were observed in arm B. There were no reported grade 4 adverse events in either arm. In conclusion, the 2-week S-1 administration followed by 1-week rest regimen appears to be a more feasible oral administration regimen for S-1 as adjuvant chemotherapy in gastric cancer.

Incidence of metachronous gastric cancer in the remnant stomach after synchronous multiple cancer surgery.

BACKGROUND: In the preoperative evaluation for gastric cancer, high-resolution endoscopic technologies allow us to detect small accessory lesions. However, it is not known if the gastric remnant after partial gastrectomy for synchronous multiple gastric cancers has a greater risk for metachronous cancer. The purpose of this study was to determine the incidence of metachronous cancer in this patient subset compared with that after solitary cancer surgery. METHODS: Data on a consecutive series of 1,281 patients gastrectomized for early gastric cancer from 1991 to 2007 were analyzed retrospectively. The 715 gastric remnants after distal gastrectomy were periodically surveyed by endoscopic examination in Shikoku Cancer Center. Among those surveyed cases, 642 patients were pathologically diagnosed with solitary lesion (SO group) and 73 patients with synchronous multiple lesions (MU group) at the time of the initial surgery. RESULTS: In the follow-up period, 15 patients in the SO group and 3 patients in the MU group were diagnosed as having metachronous cancer in the gastric remnant. The cumulative 4-year incidence rate was 1.9 % in the SO group and 5.5 % in the MU group. The difference did not reach the significant level by the log-rank test. CONCLUSIONS: The incidence of metachronous cancer is higher after multiple cancer surgery; however, the difference is not statistically significant.