Long-term outcomes of a phase II study of neoadjuvant imatinib in large gastrointestinal stromal tumors of the stomach.

BACKGROUND: Neoadjuvant treatment is recommended for large GISTs due to their friability and risk of extensive operations; however, studies on the indications and long-term results of this approach are lacking. METHODS: Patients with large (≥ 10 cm) gastric GISTs were enrolled from multiple centers in Korea and Japan after a pathologic confirmation of c-KIT ( +) GISTs. Imatinib (400 mg/d) was given for 6-9 months preoperatively, and R0 resection was intended. Postoperative imatinib was given for at least 12 months and recommended for 3 years. RESULTS: A total of 56 patients were enrolled in this study, with 53 patients receiving imatinib treatment at least once and 48 patients undergoing R0 resection. The 5-year overall survival and progression-free survival rates were 94.3% and 61.6%, respectively. Even patients with stable disease by RECIST criteria responded well to preoperative imatinib treatment and could undergo R0 resection, with most being evaluated as partial response by CHOI criteria. The optimal reduction in tumor size was achieved with preoperative imatinib treatment for 24 weeks or more. No resumption of imatinib treatment was identified as an independent prognostic factor for recurrence after R0 resection. No additional size criteria for a higher risk of recurrence were identified in this cohort with a size of 10 cm or more. CONCLUSIONS: Neoadjuvant imatinib treatment is an effective treatment option for gastric GISTs 10 cm or larger. Postoperative imatinib treatment is recommended even after R0 resection to minimize recurrence.

Analysis of risk factors affecting long-term survival in elderly patients with advanced gastric cancer.

BACKGROUND: Factors predicting postoperative complications after gastrectomy for elderly patients with gastric cancer have been analyzed in several previous studies. However, there is limited research available on risk factors related to long-term survival. AIMS: This study aimed to analyze factors affecting long-term survival after curative gastrectomy in elderly patients with advanced gastric cancer. METHODS: This study included patients aged > 75 years with histologically confirmed advanced gastric cancer stage II or greater. Before analysis, risk factors were categorized into four groups: baseline characteristics, underlying diseases, surgical and pathologic factors, and nutritional factors. RESULTS: The mean follow-up duration was 71.0 months. The 5-year overall survival and disease-specific survival rates were 51.5% and 58.3%, respectively. Kaplan-Meier curves showed that patients who were female and overweight had significantly longer survival rates than those who were male and underweight. Elderly patients who underwent a total gastrectomy had poorer survival rates than those who underwent a distal gastrectomy. Multivariate analysis demonstrated that tumor stage, extent of gastrectomy, overweight status and overall complication were independent risk factors for overall survival. DISCUSSION: Our study show that the overweight patients, the extent of gastrectomy, tumor stage and overall complications are significant risk factors affecting long-term survival. CONCLUSIONS: Therefore, surgeons may be cautious in performing total gastrectomy in elderly gastric cancer patients. Additionally, it is important to focus on improving nutritional status and mitigating overall complications.

Safety evaluation of curative gastrectomy for gastric cancer patients who underwent liver transplantation: a comparative study with conventional gastrectomy for gastric cancer patients.

BACKGROUND: We aimed to examine the technical and oncological safety of curative gastrectomy for gastric cancer patients who underwent liver transplantation. METHODS: In this study, we compared the surgical and oncological outcomes of two groups. The first group consisted of 32 consecutive patients who underwent curative gastrectomy for gastric cancer after liver transplantation (LT), while the other group consisted of 127 patients who underwent conventional gastrectomy (CG). In addition, a subgroup analysis was performed to evaluate the impact of the background differences and the surgical outcomes on the involvement of a specialized liver transplant surgery team. RESULTS: The mean operative time was significantly longer in the LT group (p < 0.05). Furthermore, there were more frequent cases of postoperative transfusion in the LT group compared to the CG group (p < 0.05). However, there were no significant differences in the overall complications between the groups (25.00 vs 23.62%, p = 0.874). The 5-year overall survival rates of the LT and CG groups were 76.7% and 90.1%, respectively (p < 0.05). The results of the subgroup analysis demonstrated no statistically significant difference in various early surgical outcomes, such as time to transfusion during surgery, first flatus, time to first soft diet, postoperative complications, hospital stay after surgery, and the number of harvested lymph nodes except for operation time. CONCLUSIONS: Despite one's medical history of undergoing LT, our study demonstrated that curative gastrectomy could be a surgically safe treatment for gastric cancer. However, further study should be conducted to identify the reason gastric cancer patients who underwent liver transplant surgery have lower overall survival rate.

Comparison of Standard D2 and Limited Lymph Node Dissection in Elderly Patients with Advanced Gastric Cancer.

BACKGROUND: Knowledge on the optimal extent of lymphadenectomy among elderly patients with advanced gastric cancer is limited. This study was designed to compare standard D2 and limited lymphadenectomy for evaluating the appropriate extent of lymphadenectomy. PATIENTS AND METHODS: We retrospectively reviewed patient's data based on a prospectively collected gastric cancer registry. The inclusion criteria were age above 75 years and histologically confirmed stage II or more advanced gastric cancer. In this study, 103 patients who underwent limited lymph node dissection and 134 patients who underwent standard D2 lymph node dissection were included to evaluate surgical and oncological outcomes using propensity score matching (PSM) analysis. RESULTS: The mean age after PSM was approximately 78 years in both groups. The Charlson Comorbidity Index was 5.81 ± 0.87 and 5.75 ± 0.76, respectively, and 12.5% of the patients in both groups had American Society of Anesthesiologists scores of more than 3. The limited lymphadenectomy group showed a shorter operation time and fewer retrieved lymph. However, other surgical outcomes and pathological data were not significantly different between the groups. No postoperative mortality within 30 days was observed. There were no significant differences in overall complications between the groups. The 3-year overall survival rates of the limited and standard lymphadenectomy groups were 58.3% and 73.6%, respectively. The 3-year recurrence-free survival rate of the limited lymphadenectomy group was lower than that of the standard lymphadenectomy group; however, the difference was not statistically significant. CONCLUSIONS: Standard D2 lymphadenectomy has better oncological outcomes in elderly patients with advanced gastric cancer.

Radiological criteria for selecting candidates for neoadjuvant chemotherapy for gastric cancer: an exploratory analysis from the PRODIGY study.

BACKGROUND: In this exploratory analysis from the PRODIGY study, we aimed to define the radiological criteria to identify patients with gastric cancer who may derive maximal clinical benefit from neoadjuvant chemotherapy. PATIENTS AND METHODS: There were 246 patients allocated to receive surgery followed by adjuvant S-1 (SC group) and 238 allocated to receive neoadjuvant chemotherapy (CSC group). As the PRODIGY's radiological method of lymph node (LN) evaluation considers short diameter and morphology (the size and morphology method), a method considering only short diameter was also employed. In the SC group, the correlation between radiologic and pathologic findings was analyzed. The hazard ratio (HR) for the progression-free survival (PFS) of the CSC group was analyzed in subgroups with different cT/N stages. RESULTS: cT4 disease showed a sensitivity of 85.6% for detecting pT4 and had a low proportion of pathologic stage (pStage) I disease (4.5%). Among the criteria determined by different cT/N stages by each method of LN positivity, those involving cT4Nany or cT4N + by both methods had a minimal proportion of pStage I disease (≤ 5%), while cT4Nany by both methods and cT4N + by the size and morphology method exhibited ≥ 75.9% sensitivity for detecting pStage III disease. The relative risk reduction in PFS of the CSC group was greatest in patients meeting the cT4Nany criterion defined by both methods (HR 0.67, 95% confidence interval 0.48-0.93). CONCLUSIONS: The cT4Nany criterion, regardless of the radiological method used for LN evaluation, may help select patients with resectable gastric cancer for neoadjuvant chemotherapy.

Determinants of clinical outcomes of gastric cancer patients treated with neoadjuvant chemotherapy: a sub-analysis of the PRODIGY study.

BACKGROUND: In this post hoc analysis of the PRODIGY study, we aimed to investigate factors associated with survival outcomes and provide evidence for designing optimal perioperative treatment strategies for gastric cancer patients receiving neoadjuvant chemotherapy. PATIENTS AND METHODS: A total of 212 patients in the neoadjuvant chemotherapy group of the PRODIGY study were included as the study population. The prognostic impact of clinicopathologic factors, including the initial radiological clinical stage (cStage) and post-neoadjuvant chemotherapy pathological stage (ypStage), was analyzed. RESULTS: The median age was 58 years. The majority of patients (77.4%) had cStage III disease, and about 10% and 25% had ypStage 0 and I disease, respectively. According to the initial cStage, progression-free survival (PFS) and overall survival (OS) were significantly different (P < 0.01). PFS and OS were also different according to the ypStage (P < 0.01). In multivariate analyses, cStage IIIC disease (vs. cStage II) and ypStage II and III disease (vs. ypStage 0/I) were independent factors for poor survival outcomes. Based on the patterns of PFS and OS according to both cStage and ypStage, three patient groups were defined. These groups showed distinct PFS and OS (P < 0.01) with 5-year PFS rates of 95.7%, 77.9%, and 31.3% and 5-year OS rates of 95.7%, 82.4%, and 42.5%, respectively. CONCLUSIONS: Both initial cStage and ypStage were independent factors for survival outcomes of gastric cancer patients treated with neoadjuvant chemotherapy. Efforts should be made to develop optimal peri-operative treatment strategies for patients at different risks according to cStage and ypStage.

Preoperative nutritional risk index and postoperative one-year skeletal muscle loss can predict the prognosis of patients with gastric adenocarcinoma: a registry-based study.

BACKGROUND: Patients with gastric cancer have an increased nutritional risk and experience a significant skeletal muscle loss after surgery. We aimed to determine whether muscle loss during the first postoperative year and preoperative nutritional status are indicators for predicting prognosis. METHODS: From a gastric cancer registry, a total of 958 patients who received curative gastrectomy followed by chemotherapy for stage 2 and 3 gastric cancer and survived longer than 1 year were investigated. Clinical and laboratory data were collected. Skeletal muscle index (SMI) was assessed based on the muscle area at the L3 level on abdominal computed tomography. RESULTS: Preoperative nutritional risk index (NRI) and postoperative decrement of SMI (dSMI) were significantly associated with overall survival (hazards ratio: 0.976 [95% CI: 0.962-0.991] and 1.060 [95% CI: 1.035-1.085], respectively) in a multivariate Cox regression analysis. Recurrence, tumor stage, comorbidity index were also significant prognostic indicators. Kaplan-Meier analyses exhibited that patients with higher NRI had a significantly longer survival than those with lower NRI (5-year overall survival: 75.8% vs. 63.0%, P <  0.001). In addition, a significantly better prognosis was observed in a patient group with less decrease of SMI (5-year overall survival: 75.7% vs. 66.2%, P = 0.009). A logistic regression analysis demonstrated that the performance of preoperative NRI and dSMI in mortality prediction was quite significant (AUC: 0.63, P <  0.001) and the combination of clinical factors enhanced the predictive accuracy to the AUC of 0.90 (P <  0.001). This prognostic relevance of NRI and dSMI was maintained in patients experiencing tumor recurrence and highlighted in those with stage 3 gastric adenocarcinoma. CONCLUSIONS: Preoperative NRI is a predictor of overall survival in stage 2 or 3 gastric cancer patients and skeletal muscle loss during the first postoperative year was significantly associated with the prognosis regardless of relapse in stage 3 tumors. These factors could be valuable adjuncts for accurate prediction of prognosis in gastric cancer patients.

Discovery and validation of an expression signature for recurrence prediction in high-risk diffuse-type gastric cancer.

BACKGROUND: Diffuse type gastric cancer (DGC), represented by low sensitivity to chemotherapy and poor prognosis, is a heterogenous malignancy in which patient subsets exhibit diverse oncological risk-profiles. This study aimed to develop molecular biomarkers for robust prognostic risk-stratification and improve survival outcomes in patients with diffuse type gastric cancer (DGC). METHODS: We undertook a systematic and comprehensive discovery and validation effort to identify recurrence prediction biomarkers by analyzing genome-wide transcriptomic profiling data from 157 patients with DGC, followed by their validation in 254 patients from 2 clinical cohorts. RESULTS: Genome-wide transcriptomic profiling identified a 7-gene panel for robust prediction of recurrence in DGC patients (AUC = 0.91), which was successfully validated in an independent dataset (AUC = 0.86). Examination of 180 specimens from a training cohort allowed us to establish a gene-based risk prediction model (AUC = 0.78; 95% CI 0.71-0.84), which was subsequently validated in an independent cohort of 74 GC patients (AUC = 0.83; 95% CI 0.72-0.90). The Kaplan-Meier analyses exhibited a consistently superior performance of our risk-prediction model in the identification of high- and low-risk patient subgroups, which was significantly improved when we combined our gene signature with the tumor stage in both clinical cohorts (AUC of 0.83 in the training cohort and 0.89 in the validation cohort). Finally, for an easier clinical translation, we established a nomogram that robustly predicted prognosis in patients with DGC. CONCLUSIONS: Our novel transcriptomic signature for risk-stratification and identification of high-risk patients with recurrence could serve as an important clinical decision-making tool in patients with DGC.

Sporadic Early-Onset Diffuse Gastric Cancers Have High Frequency of Somatic CDH1 Alterations, but Low Frequency of Somatic RHOA Mutations Compared With Late-Onset Cancers.

BACKGROUND & AIMS: Early-onset gastric cancer, which develops in patients younger than most gastric cancers, is usually detected at advanced stages, has diffuse histologic features, and occurs more frequently in women. We investigated somatic genomic alterations associated with the unique characteristics of sporadic diffuse gastric cancers (DGCs) from younger patients. METHODS: We conducted whole exome and RNA sequence analyses of 80 resected DGC samples from patients 45 years old or younger in Korea. Patients with pathogenic germline mutations in CDH1, TP53, and ATM were excluded from the onset of this analysis, given our focus on somatic alterations. We used MutSig2CV to evaluate the significance of mutated genes. We recruited 29 additional early-onset Korean DGC samples and performed SNP6.0 array and targeted sequencing analyses of these 109 early-onset DGC samples (54.1% female, median age, 38 years). We compared the SNP6.0 array and targeted sequencing data of the 109 early-onset DGC samples with those from diffuse-type stomach tumor samples collected from 115 patients in Korea who were 46 years or older (late onset) at the time of diagnosis (controls; 29.6% female, median age, 67 years). We compared patient survival times among tumors from different subgroups and with different somatic mutations. We performed gene silencing of RHOA or CDH1 in DGC cells with small interfering RNAs for cell-based assays. RESULTS: We identified somatic mutations in the following genes in a significant number of early-onset DGCs: the cadherin 1 gene (CDH1), TP53, ARID1A, KRAS, PIK3CA, ERBB3, TGFBR1, FBXW7, RHOA, and MAP2K1. None of 109 early-onset DGC cases had pathogenic germline CDH1 mutations. A higher proportion of early-onset DGCs had mutations in CDH1 (42.2%) or TGFBR1 (7.3%) compared with control DGCs (17.4% and 0.9%, respectively) (P < .001 and P = .014 for CDH1 and TGFBR1, respectively). In contrast, a smaller proportion of early-onset DGCs contained mutations in RHOA (9.2%) than control DGCs (19.1%) (P = .033). Late-onset DGCs in The Cancer Genome Atlas also contained less frequent mutations in CDH1 and TGFBR1 and more frequent RHOA mutations, compared with early-onset DGCs. Early-onset DGCs from women contained significantly more mutations in CDH1 or TGFBR1 than early-onset DGCs from men. CDH1 alterations, but not RHOA mutations, were associated with shorter survival times in patients with early-onset DGCs (hazard ratio, 3.4; 95% confidence interval, 1.5-7.7). RHOA activity was reduced by an R5W substitution-the RHOA mutation most frequently detected in early-onset DGCs. Silencing of CDH1, but not RHOA, increased migratory activity of DGC cells. CONCLUSIONS: In an integrative genomic analysis, we found higher proportions of early-onset DGCs to contain somatic mutations in CDH1 or TGFBR1 compared with late-onset DGCs. However, a smaller proportion of early-onset DGCs contained somatic mutations in RHOA than late-onset DGCs. CDH1 alterations, but not RHOA mutations, were associated with shorter survival times of patients, which might account for the aggressive clinical course of early-onset gastric cancer. Female predominance in early-onset gastric cancer may be related to relatively high rates of somatic CDH1 and TGFBR1 mutations in this population.

Risk of osteoporosis after gastrectomy in long-term gastric cancer survivors.

INTRODUCTION: Although early detection and successful gastrectomy have improved the survival of patients with gastric cancer, long-term health problems remain troubling. We evaluated the prevalence of osteoporosis and its risk factors in long-term survivors of gastric cancer after gastrectomy. METHODS: We reviewed the medical records of a tertiary hospital between 2007 and 2014 to identify survivors of gastric cancer who had visited our center at around 5 years after gastrectomy. We evaluated their health status, including bone mineral density (BMD). Dual-energy X-ray absorptiometry was used to measure the BMD of the lumbar spine and femur (total and neck area). The prevalence of osteoporosis, defined by a BMD T score <-2.5, was investigated, and clinical variables associated with the presence of osteoporosis were identified. RESULTS: A total of 250 survivors were included. The mean age was 54.6 years old, and the median follow-up was 6.0 years. The prevalence of osteoporosis was 34.0% (27.4% for men and 43.6% for women). Older age [odds ratio (OR) 5.50, 95% CI 2.33-13.00], higher alkaline phosphatase levels before gastrectomy (OR 5.67, 95% CI 1.36-23.64), and marked weight loss (≥20%) after gastrectomy (OR 3.59, 95% CI 1.32-9.77) were independently associated with the presence of osteoporosis. CONCLUSIONS: In our cohort, osteoporosis was commonly observed in long-term survivors of gastric cancer, and several risk factors for it were identified. To reduce the risk of osteoporosis after gastrectomy, maintaining adequate body weight may be necessary.

Long-term outcomes of endoscopic submucosal dissection versus surgery in early gastric cancer meeting expanded indication including undifferentiated-type tumors: a criteria-based analysis.

BACKGROUND: Endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) meeting the expanded indication is considered investigational. We aimed to compare long-term outcomes of ESD and surgery for EGC in the expanded indication based on each criterion. METHODS: This study included 1823 consecutive EGC patients meeting expanded indication conditions and treated at a tertiary referral center: 916 and 907 patients underwent surgery or ESD, respectively. The expanded indication included four discrete criteria: (I) intramucosal differentiated tumor, without ulcers, size >2 cm; (II) intramucosal differentiated tumor, with ulcers, size ≤3 cm; (III) intramucosal undifferentiated tumor, without ulcers, size ≤2 cm; and (IV) submucosal invasion <500 µm (sm1), differentiated tumor, size ≤3 cm. We selected 522 patients in each group by propensity score matching and retrospectively evaluated each group. The primary outcome was overall survival (OS); the secondary outcomes were disease-specific survival (DSS), recurrence-free survival (RFS), and treatment-related complications. RESULTS: In all patients and subgroups meeting each criterion, OS and DSS were not significantly different between groups (OS and DSS, all patients: p = 0.354 and p = 0.930; criteria I: p = 0.558 and p = 0.688; criterion II: p = 1.000 and p = 1.000; criterion III: p = 0.750 and p = 0.799; and criterion IV: p = 0.599 and p = 0.871). RFS, in all patients and criterion I, was significantly shorter in the ESD group than in the surgery group (p < 0.001 and p < 0.003, respectively). The surgery group showed higher rates of late and severe treatment-related complications than the ESD group. CONCLUSIONS: ESD may be an alternative treatment option to surgery for EGCs meeting expanded indications, including undifferentiated-type tumors.

Phase II study of neoadjuvant imatinib in large gastrointestinal stromal tumours of the stomach.

BACKGROUND: Gastrointestinal stromal tumours (GISTs) with high-risk features have poor prognosis even if adjuvant treatment is given. Neoadjuvant imatinib may increase the cure rate by shrinking large GISTs and preserve organ function. METHODS: We conducted an Asian multinational phase II study for patients with gastric GISTs ≥10 cm. Patients received neoadjuvant imatinib (400 mg/day) for 6-9 months. The primary end point was R0 resection rate. RESULTS: A total of 56 patients were enroled in this study. In the full analysis set of 53 patients, neoadjuvant imatinib for ≥6 months was completed in 46 patients. Grade 3-4 neutropenia and rash occurred in 8% and 9%, respectively, but there were no treatment-related deaths. The response rate by RECIST was 62% (95% CI, 48-75%). The R0 resection rate was 91% (48/53) (95% CI, 79-97%). Preservation of at least half of the stomach was achieved in 42 of 48 patients with R0 resection. At the median follow-up time of 32 months, 2-year overall and progression-free survival rates were 98% and 89%, respectively. CONCLUSIONS: Neoadjuvant imatinib treatment for 6-9 months is a promising treatment for large gastric GISTs, allowing a high R0 resection rate with acceptable toxicity.

Comparison the sixth and seventh editions of the AJCC staging system for T1 gastric cancer: a long-term follow-up study of 2124 patients.

BACKGROUND/AIM: The aim of this study was to establish an appropriate TNM staging system for early gastric cancer. METHODOLOGY: We evaluated 2124 patients who had undergone gastrectomy for early gastric cancer between 1989 and 2001. RESULTS: Using the seventh edition of the American Joint Committee on Cancer (AJCC) staging system, we found no significant differences in tumor recurrence and survival between N1 and N2 cancers or between N3a and N3b cancers, whereas the survival curves for N2 and N3 cancers were quite different. Similarly, using the classification in the sixth edition of the AJCC staging system, we found no significant difference in survival between the N2 and N3 cancer groups, whereas the survival curves for N1 versus N2 or N3 cancers were quite different. CONCLUSIONS: The classifications in the sixth and seventh editions of the AJCC staging system have a limitation for T1 gastric cancer (early gastric cancer).

Phase 2 study of adjuvant chemotherapy with docetaxel, capecitabine, and cisplatin in patients with curatively resected stage IIIB-IV gastric cancer.

OBJECTIVE: Postoperative chemotherapy with S-1 or capecitabine plus oxaliplatin is a standard treatment for resectable gastric cancer (GC). However, survival outcomes of stage IIIB-IV (M0) GC cases are still poor. We investigated the efficacy and safety of docetaxel, capecitabine, and cisplatin (DXP) in patients with stage IIIB-IV GC. METHODS: This was a single-arm phase 2 study that included patients with stage IIIB-IV GC who underwent D2 gastrectomy. Patients received six cycles of docetaxel [60 mg/m2 on day 1 (D1)], capecitabine (1,875 mg/m2/day on D1-14), and cisplatin (60 mg/m2 on D1) every 3 weeks. The primary end-point was recurrence-free survival (RFS). RESULTS: A total of 46 GC patients between January 2007 and August 2008 were included. After a median follow-up of 56.1 months (range 52.2-64.1), the median RFS and overall survival (OS) were 26.9 months (95 % CI 7.5-46.4) and 43.9 months (95 % CI 29.2-58.7), respectively. The 5-year RFS and OS rates were 39.1 and 41.3 %, respectively. The most common grade 3/4 toxicities were neutropenia (40 %), anorexia (22 %), and febrile neutropenia (15 %). CONCLUSIONS: Adjuvant DXP is feasible and effective for patients with stage IIIB-IV GC. A phase 3 study comparing triplet and doublet regimens for these patients is ongoing.

Phase I/II study of a combination of capecitabine, cisplatin, and intraperitoneal docetaxel (XP ID) in advanced gastric cancer patients with peritoneal metastasis.

BACKGROUND: This study was conducted to determine the recommended dose (RD) of intraperitoneal docetaxel (ID) in combination with systemic capecitabine and cisplatin (XP) and to evaluate its efficacy and safety at the RD in advanced gastric cancer (AGC) patients with peritoneal metastasis. METHODS: AGC patients with peritoneal metastasis received XP ID, which consists of 937.5 mg/m2 of capecitabine twice daily on days 1-14, 60 mg/m2 of intravenous cisplatin on day 1, and intraperitoneal docetaxel at 3 different dose levels (60, 80, or 100 mg/m2) on day 1, every 3 weeks. In the phase I study, the standard 3 + 3 method was used to determine the RD of XP ID. In the phase II study, patients received RD of XP ID. RESULTS: In the phase I study, ID 100 mg/m2 was chosen as the RD, with one dose-limiting toxicity (ileus) out of six patients. The 39 AGC patients enrolled in the phase II study received the RD of XP ID. The median progression-free survival was 11.0 months (95% CI 6.9-15.1), and median overall survival was 15.1 months (95% CI 9.1-21.1). The most frequent grade 3/4 adverse events were neutropenia (38.6%) and abdominal pain (30.8%). The incidence of abdominal pain cumulatively increased in the later treatment cycles. CONCLUSIONS: Our study indicated that XP ID was effective, with manageable toxicities, in AGC patients with peritoneal metastasis. As the cumulative incidence of abdominal pain was probably related to bowel irritation by ID, it might be necessary to modify the dose.

Associations between CYP2A6 polymorphisms and outcomes of adjuvant S-1 chemotherapy in patients with curatively resected gastric cancer.

BACKGROUND: Oral fluoropyrimidine S-1 contains tegafur, which is metabolized to 5-fluorouracil by cytochrome P450 2A6 (CYP2A6). We here examined associations between CYP2A6 polymorphisms and treatment outcomes of adjuvant S-1 in gastric cancer patients. METHODS: Patients received adjuvant S-1 (40 mg/m2 twice daily, days 1-28, every 6 weeks for eight cycles) after curative surgery for pathological stage II-III gastric cancer. We analyzed the wild-type allele (W) (CYP2A6*1) and four variant alleles (V) (CYP2A6*4, *7, *9, *10) that abolish or reduce this enzyme activity. RESULTS: Patients (n = 200) were enrolled between November 2007 and July 2013 with the following clinical characteristics: median age, 57 years (range, 32-83 years); 128 men, 72 women. With a median follow-up of 46.4 months, the 3-year relapse-free survival (RFS) and overall survival (OS) rates were 83.1 % (95 % CI, 77.7-88.5 %) and 94.8 % (95 % CI, 91.6-98.0 %), respectively. Genotype distributions were as follows: W/W (n = 49, 24.5 %), W/V (n = 94, 47.0 %), and V/V (n = 57, 28.5 %). Overall toxicity did not differ according to genotype for any grade (p = 0.612) or grade ≥3 (p = 0.143). However, RFS differed significantly according to CYP2A6 genotype. The 3-year RFS rates were 95.9 % for W/W, 83.1 % for W/V, and 72.5 % for V/V (p = 0.032). Carriers of W/V and V/V genotypes had a poorer RFS with a hazard ratio of 3.41 (95 % CI, 1.01-11.52; p = 0.049) and 4.03 (95 % CI, 1.16-13.93; p = 0.028), respectively, compared with the W/W genotype. CONCLUSIONS: CYP2A6 polymorphisms are not associated with toxicity of S-1 chemotherapy, but correlate with the efficacy of S-1 in the adjuvant setting for gastric cancer.

Comparison of long-term outcomes of endoscopic submucosal dissection and surgery for esophagogastric junction adenocarcinoma.

BACKGROUND: Endoscopic submucosal dissection (ESD) has become accepted as the standard treatment for early gastric cancer. However, comparative outcomes of ESD and surgery have not been evaluated for adenocarcinoma in the esophagogastric junction (EGJ). We investigated the long-term outcomes of ESD compared with those of surgery for adenocarcinoma in the EGJ. METHODS: Patients who underwent ESD or surgery for Siewert type II adenocarcinoma between 2005 and 2010 and who met the absolute and expanded criteria for endoscopic resection were eligible. Clinical features and treatment outcomes were retrospectively reviewed using medical records. RESULTS: Of the 79 patients included, 40 underwent ESD and 39 underwent surgery. During the median follow-up period of 60.9 months (range, 13.1-125.4 months), the 5-year overall survival rates were 93.9% and 97.3% for the ESD and surgery groups, respectively (p = 0.376). There were no gastric cancer-related deaths in either group. Adverse events occurred in 11 patients (13.9%) overall, and the incidence of treatment-related adverse events was similar between the two groups (10.0% vs. 17.9%, p = 0.308). CONCLUSIONS: ESD may be an effective alternative to surgery for the treatment of early gastric cancer in the EGJ based on the comparable long-term outcomes.

Clinical application of early gastric carcinoma with lymphoid stroma based on lymph node metastasis status.

BACKGROUND: Gastric carcinoma with lymphoid stroma (GCLS) is characterized by undifferentiated carcinoma mixed with prominent lymphoid infiltration. GCLS has unique clinicopathological features and a better prognosis compared to other types of gastric cancer. We analyzed the clinicopathological features of early GCLS in relation to lymph node metastasis (LNM). METHODS: We performed a retrospective analysis of 241 patients diagnosed with GCLS confined to the mucosa or the submucosa between March 1998 and December 2015. Their data were compared with those from 1219 patients who underwent resection for differentiated early gastric cancer (EGC). RESULTS: Of the 241 patients analyzed, 33 (13.7%) had intramucosal cancers and 208 (86.3%) had cancers that penetrated the submucosa. Compared to differentiated EGC, early GCLS was more prevalent in younger individuals and in men, tended to be proximally located, was highly associated with Epstein-Barr virus (EBV) infection (89.2%), and had a lower risk of LNM. The 5-year disease-specific survival rate of patients with early GCLS was 98.3% but depended significantly on LNM status (p < 0.001) and EBV infection status (p = 0.039). The risk of LNM from mucosal GCLS and submucosal GCLS was 0% [95% confidence interval (CI) 0-9.1] and 10% (95% CI 6.8-15.2), respectively. On multivariate analysis, LNM was found to be associated with tumor size (p = 0.022) and lymphovascular invasion (p = 0.002) in addition to tumor depth. CONCLUSIONS: Early GCLS has distinct clinicopathological features depending on age, sex, tumor location, EBV infection status, and LNM status. Tailored therapies, including endoscopic treatment, are needed based on the distinct clinicopathological features of early GCLS.

Totally laparoscopic total gastrectomy using the overlap method; early outcomes of 50 consecutive cases.

BACKGROUND: Construction of an esophagojejunostomy is still a challenging procedure in totally laparoscopic total gastrectomy (TLTG), and there is no standard anastomosing method. The aims of this study were to describe our TLTG with the overlap method using a linear stapler and report surgical outcomes. METHODS: From January 2015 to April 2016, 50 patients underwent TLTG using the overlap method for gastric cancer. The procedures were performed by a single surgeon, and the patients' medical records were reviewed. Their clinicopathologic characteristics, operation time, date of flatus, hospital stay, morbidity, and mortality were analyzed. RESULTS: The median age and body mass index were 56 years and 23.5, respectively. Stage 1A tumors were the most common. Mean operating time was 144.6 min, and no cases required changing to open laparotomy during surgery. On average, flatus occurred 3.5 days after surgery, and patients were discharged 6.8 days after surgery. No patient experienced anastomosis leakage, stricture, duodenal stump leakage, luminal bleeding, pancreatic fistula, or wound problems. There were two cases of intra-abdominal bleeding that required additional surgery. Intra-abdominal fluid collection and mechanical ileus occurred in two patients, respectively, and were successfully managed with conservative treatment. CONCLUSIONS: We reported favorable surgical outcomes of TLTG using the overlap method. It is a feasible and safe option for treatment of gastric cancer.

Mediastinal lymph node dissection and distal esophagectomy is not essential in early esophagogastric junction adenocarcinoma.

BACKGROUND: Optimal extent of surgery remains controversial in types 2 and 3 adenocarcinoma of esophagogastric junction (AEG). We aimed to determine whether the extended procedure including mediastinal lymphadenectomy is essential in all patients with AEG by comparing prognosis and recurrence of proximal gastric adenocarcinoma based on total gastrectomy with intra-abdominal lymphadenectomy. METHODS: The clinicopathologic characteristics of 672 patients (type 2: 90, type 3: 211, upper third of the stomach: 371 cases) who underwent curative total gastrectomy with lymphadenectomy between 2003 and 2009 were reviewed. RESULTS: Recurrence was observed in 36.7, 16.1, and 16.1% of cases of type 2 AEG, type 3 AEG, and cancer of the upper third of the stomach, respectively. The 5-year disease-free survival rates were 62.6, 82.5, and 84.6%, respectively. Subgroup analysis revealed that in early cancers, there was no difference in survival between the groups (93.2 vs. 96.7 vs. 98.7%) but in advanced cancers, there was a difference (47.9 vs. 75.4 vs. 71.8%, P < 0.001). There was no survival difference in stage 1 (97.5 vs. 98.7 vs. 98.3%), but, in stage 2, type 2 AEG had a worse prognosis (41.9 vs. 92.1 vs. 83.0%). Types 2 and 3 advanced AEG had higher rates of locoregional recurrence, especially in the vicinity of the esophagojejunostomy and mediastinal lymph nodes compared to proximal gastric cancer. CONCLUSIONS: Total gastrectomy without mediastinal lymphadenectomy might produce favorable outcomes in early AEG and acquisition of a greater length of proximal margin, and removal of mediastinal lymph nodes might be helpful in advanced cancers.