Long-term Results of a Phase II Study of Neoadjuvant SOX for Advanced Gastric Cancer.

BACKGROUND/AIM: This study aimed to evaluate the long-term survival outcomes from our previous study: a phase II study of neoadjuvant chemotherapy with S-1 plus oxaliplatin for cT4 or N2-3 advanced gastric cancer. PATIENTS AND METHODS: The patients with clinical T4 and/or N2 or more lymph nodes received two cycles (3 weeks per cycle) of neoadjuvant chemotherapy with S-1 plus oxaliplatin (oxaliplatin at 130 mg/m2 on day 1 and S-1 at 80-120 mg/day on days 1 to 14), followed by gastrectomy with D2 lymphadenectomy. The final preplanned analysis of long-term outcomes, including overall and relapse-free survival, was performed. This trial has been completed and registered with the University Hospital Medical Information Network Clinical Trials Registry under number UMIN 000024656. RESULTS: Between May 2016 and March 2019, 30 patients were enrolled. All patients completed the protocol. After a median follow-up of 50 months for surviving patients, the 3-year overall and recurrence-free survival rates were 80.0% and 76.7%, respectively, at the last follow-up in March 2023, whereas the 5-year overall and recurrence-free survival rates were 72.7% and 73.0%, respectively. CONCLUSION: The administration of two cycles of neoadjuvant chemotherapy with S-1 plus oxaliplatin, followed by D2 gastrectomy, was associated with relatively good long-term oncologic outcomes for patients with high-risk gastric cancer.

Early administration of postoperative BCAA-enriched PPN may improve lean body mass loss in gastric cancer patients undergoing gastrectomy.

BACKGROUND: It has been reported that weight loss or lean body mass (LBM) loss after gastrectomy for gastric cancer is associated with prognosis and nutritional support alone is insufficient to prevent LBM loss. Branched-chain amino acids (BCAA) play an important role in muscle catabolism, however their clinical effects on suppression of LBM loss in gastric cancer patients undergoing gastrectomy remains elusive. In this current study, we investigated the effect of our original PPN regimen including BCAA (designated to BCAA-regimen) on LBM loss. METHODS: We conducted a randomized controlled trial (RCT) at a single institution where patients undergoing gastrectomy were assigned to either receive a five-day early postoperative course of the BCAA-regimen (BCAA group) or conventional nutrition. The primary endpoint was the % reduction in LBM at postoperative day 7. The secondary endpoints included the % reduction in LBM at 1 and 3 months postsurgery. RESULTS: At postoperative day 7, LBM loss in the BCAA group tended to be lower than in the control group (0.16% vs. 1.7%, respectively; P = 0.21), while at 1 month postsurgery, LBM loss in the BCAA group was significantly different to that of the control group (- 0.3% vs. 4.5%, respectively; P = 0.04). At 3 months postgastrectomy, however, LBM loss was similar between the BCAA and the control groups. CONCLUSION: Our RCT clinical trial clarified that early administration of the postoperative BCAA regimen improved LBM loss at 1 month after surgery in gastric cancer patients undergoing gastrectomy.

A Case of Pathologically Complete Response After Nivolumab Combined with Chemotherapy in a Gastric Cancer Patient with Virchow's Lymph Node Metastasis.

Gastric cancer with Virchow's lymph node metastasis (LNM) is not indicated for initial curative surgery. Although there have been some case reports of curative resections after pre-operative treatment, including immune checkpoint inhibitors (ICIs), there is no consensus regarding the optimal timing of surgery. We describe a rare case of initially unresectable gastric cancer treated preoperatively with nivolumab combined chemotherapy, which achieved a pathologically complete response. An 82-year-old man was referred for gastric cancer treatment. Contrast-enhanced computed tomography revealed stomach wall thickening and swollen left supraclavicular LN. This gastric cancer was assessed as unresectable due to the presence of Virchow's LNM; therefore, chemotherapy and ICI using S-1 plus oxaliplatin plus nivolumab were administered. After three courses of treatment, the primary tumor and Virchow's LN showed a marked reduction in size. The patient underwent Virchow's LNM resection as a preliminary step to determine indications for curative surgery. A pathological examination revealed no viable cancer cells were found inside the resected LN. The patient underwent distal gastrectomy. Pathological examination revealed complete degeneration of the primary tumor and regional LN without residual carcinoma. The patient did not receive adjuvant chemotherapy and survived with no evidence of recurrence for one year after the initial treatment.

Comparative analysis of the outcomes of gastrectomy vs. endoscopic mucosal resection or endoscopic submucosal dissection for the treatment of gastric tube cancer after esophagectomy.

This study investigated the clinical characteristics of patients with gastric tube cancer following esophagectomy at our hospital, and to examine the outcomes of gastrectomy versus endoscopic submucosal dissection. Of 49 patients who underwent treatment for gastric tube cancer that developed 1 year or more after esophagectomy, 30 patients underwent subsequent gastrectomy (Group A), and 19 patients underwent endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) (Group B). The characteristics and outcomes of these two groups were compared. The interval between esophagectomy and diagnosis of gastric tube cancer ranged from 1 to 30 years. The most common location was the lesser curvature of the lower gastric tube. When the cancer was detected early, EMR or ESD was performed, and the cancer did not recur. In advanced tumors, gastrectomy was performed but the gastric tube was difficult to approach and lymph node dissection was difficult; two patients died as a result of the gastrectomy. In Group A, recurrence occurred most often as axillary lymph node, bone, or liver metastases; in Group B, no recurrence or metastases were observed. In addition to recurrence and metastasis, gastric tube cancer is often observed after esophagectomy. The present findings highlight the importance of early detection of gastric tube cancer after esophagectomy and that the EMR and ESD procedures are safe and have significantly fewer complications compared with gastrectomy. Follow-up examinations should be scheduled with consideration given to the most frequent sites of gastric tube cancer occurrence and the time elapsed since esophagectomy.

Short- and long-term outcomes of robotic-assisted laparoscopic surgery for rectal cancer: A single-center retrospective cohort study.

INTRODUCTION: Whether rectal cancer surgery by robotic-assisted laparoscopic surgery provides beneficial advantages remains controversial. Although favorable outcomes in terms of the safety and technical feasibility of robotic-assisted laparoscopic surgery have been demonstrated for rectal cancer, long-term oncological outcomes for robotic-assisted laparoscopic surgery have only been examined in a few studies. This retrospective study of subjects who underwent robotic-assisted laparoscopic surgery evaluated short- and long-term outcomes of consecutive rectal cancer patients. METHODS: Between November 2016 and January 2020, we analyzed the records of 62 consecutive patients who underwent robotic-assisted laparoscopic surgery for rectal adenocarcinoma without distant metastasis to evaluate short- and long-term outcomes. RESULTS: Tumors were located in the lower or mid-rectum (88.7%) in most patients. The median operative time was 357 min. No patient received transfusions, and the median blood loss was 10.5 ml. Open laparotomy was not required in any patient. A Clavien-Dindo classification of all grades was observed in 12 patients (19.4%). Positive radial margin was not observed in any patient. Duration of median follow-up was 40.5 mo, while 3-y overall survival and 3-y relapse-free survival rates were 96.8% and 85.0%, respectively. The local recurrence rate was 3.4%. CONCLUSION: Favorable short- and long-term outcomes demonstrated robotic-assisted laparoscopic surgery was safe and technically feasible for rectal cancer.

Comparison of short-term outcomes of robotic-assisted and conventional laparoscopic surgery for rectal cancer: A propensity score-matched analysis.

INTRODUCTION: The advantages of robotic-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. This study clarified and compared the short-term outcomes of RALS for rectal cancer with those of conventional laparoscopic surgery (CLS). METHODS: The records of 303 consecutive patients who underwent RALS or CLS for rectal adenocarcinoma between November 2016 and November 2021 were analyzed using propensity score-matched analysis. After matching, 188 patients were enrolled in our study to compare short-term outcomes, such as operative results, postoperative complications, and pathological findings, in each group. RESULTS: After matching, baseline characteristics were comparable between groups. Although operative time in the RALS group was significantly longer than in the CLS group (p < 0.0001), the conversion rate to open laparotomy and the postoperative complication rate in the RALS group were significantly lower than in the CLS group (p = 0.0240 and p = 0.0109, respectively). Blood loss was comparable between groups. In the RALS group, postoperative hospital stay and days to soft diet were significantly shorter than those in the CLS group (p = 0.0464 and p < 0.0001, respectively). No postoperative mortality was observed in either group and significant differences were observed in resection margins and number of lymph nodes harvested. CONCLUSION: Robotic-assisted laparoscopic surgery for rectal cancer was safe, technically feasible, and had acceptable short-term outcomes. Further studies are required to validate long-term oncological outcomes.

Improved anastomotic technique for esophagojejunal anastomosis using circular stapler.

PURPOSE: In total gastrectomy, Roux-en-Y reconstruction with esophagojejunal anastomosis has been widely used in gastrointestinal reconstruction. In the case of anastomotic leakage of RY reconstruction, esophagojejunal anastomosis should be paid attention, and esophageal fragility is considered the reason for the leakage. Here, we introduce an atraumatic and innovative technique for esophagojejunostomy. METHODS: We prospectively performed routine novel esophagojejunal anastomosis using circular stapler device and reviewed the records of 14 consecutive patients with gastric cancer who underwent open total gastrectomy at Kitasato University Hospital from April 2019 to March 2020. By placing about 10 stay sutures around the entire esophageal stump, the esophageal stump can be opened to the maximum diameter. The forceps grasping the tissue was not necessary for these procedures, consequently preventing either tears the esophageal stump tissue or narrowing the esophageal lumen. RESULTS: These 14 cases were far advanced cases of gastric cancer, 6 cases of splenectomy and 3 cases of distal pancreatectomy. No technical problems such as esophageal tear were observed in all cases. Postoperative complications were observed in 6 patients (42.9%), and their contents varied. However, they all improved conservatively. Regarding anastomotic complications, anastomotic leakage of Clavien-Dindo-II was observed in one case, but it improved conservatively. CONCLUSION: Our new atraumatic anastomosis technique could abolish problems such as tear of esophagus wall due to introduce a larger-sized anvil, trauma of esophageal wall by grasping with forceps such as Alice or Babcock. Consequently, the atraumatic and innovative technique might make the esophagojejunostomy safe. This method might prevent anastomotic leakage and other complications effectively.

Pancreas-contactless gastrectomy for gastric cancer prevents postoperative inflammation.

BACKGROUND: Pancreas-related complications after laparoscopic gastrectomy (LG) for gastric cancer can be fatal. We developed a gastrectomy procedure with no pancreas contact to prevent such complications and herein report the surgical outcomes. METHODS: We retrospectively reviewed 182 consecutive patients with gastric cancer who underwent LG at Kitasato University Hospital from January 2017 to January 2020. These patients were divided into a pancreas-contact group (C group) and pancreas-contactless group (CL group) for comparison of postoperative complications, and inflammatory parameters such as body temperature (BT) and C-reactive protein (CRP). RESULTS: Postoperative complications of CDc grade ≧ IIIa were significantly fewer in the CL group than in the C group [0/76 (0%) vs. 6/106 (5.7%), P = 0.035]. The median drain amylase (drain-AMY) on postoperative day 1 (POD1) was significantly lower in the CL group than in the C group (641 vs. 1162 IU/L, P = 0.02), as was BT at POD1 (37.4 °C vs. 37.7 °C, P = 0.04), the patient group with a BT above 37.5 °C at POD3 [5/76 (6.5%) vs. 18/106 (17%), P = 0.037], and those showing a CRP above 20.0 mg/dL at POD3 [5/76 (6.5%) vs. 20/106 (19%), P = 0.018]. CONCLUSIONS: Our technique to prevent pancreas contact during supra-pancreatic lymph node dissection during LG could minimize the inflammatory response and prevent further postoperative complications. Further large-scale, prospective studies are now required.

Haploinsufficiency by minute MutL homolog 1 promoter DNA methylation may represent unique phenotypes of microsatellite instability-gastric carcinogenesis.

Promoter DNA methylation of MutL homolog 1 (MLH1) is considered to play a causative role in microsatellite instability (MSI) carcinogenesis in primary gastric cancer, and a high MSI status is associated with treatment sensitivity to human cancers. Nevertheless, clinicopathological analysis is defective for MLH1 methylation status in a quantitative manner. We newly developed quantitative methylation specific PCR using a TaqMan probe and applied it to 138 patients with primary gastric cancer who underwent gastrectomy in addition to basic molecular features such as MSI, Epstein Barr virus, and other DNA methylation status. (1) In primary gastric cancer, median methylation value was 0.055, ranging from 0 to 124.3. First, MLH1 hypermethylation was strongly correlated with MSI-High/MSI-Low status and suppressed immunostaining (P < 0.0001). (2) The MLH1 hypermethylation was associated with advanced age (P = 0.0048), antral location (P = 0.0486), synchronous multiple gastric cancer (P = 0.0001), and differentiated histology (P = 0.028). (3) Log-rank plot analysis identified the most relevant cut-off value (0.23) to reflect gentle phenotypes in MLH1 hypermethylation cases (P = 0.0019), especially in advanced gastric cancer (P = 0.0132), which are designated as haploinsufficiency of MSI (MSI-haplo) phenotype in this study. (4) In synchronous multiple gastric cancer, MLH1 hypermethylation was not necessarily confirmed as field cancerization. (5) MSI-haplo defined by MLH1 methylation status represented distinct prognostic phenotype even after molecular classifications. MLH1 hypermethylation designated as MSI-haplo may represent unique prognostic phenotype during gastric carcinogenesis.

Laparoscopic and endoscopic cooperative surgery for advanced gastric cancer as palliative surgery in elderly patients: a case report.

BACKGROUND: The number of elderly patients with gastric cancer is increasing, with the very elderly often refusing radical gastrectomy with lymph node dissection. Such a patient presented to us and we proposed a palliative surgery involving gastric local resection using laparoscopy endoscopy cooperative surgery (LECS). CASE PRESENTATION: An 89-year-old woman presented to our hospital with progressing anemia. She had an aortic arch replacement for aortic dissection 6 months previously and was taking antithrombotic drugs for atrial fibrillation. She was diagnosed with advanced gastric cancer, and we presented a radical resection treatment plan involving distal gastrectomy with lymph node dissection. However, she strongly refused undergoing radical gastric cancer resection. We believed that at least local control of the tumor could be effective in preventing future bleeding or stenosis due to tumor progression. Therefore, we proposed a local gastrectomy with LECS as an optional treatment, and she agreed to this treatment. The surgery was performed with minimal blood loss, and no postoperative complications were observed. Histopathological examination revealed a 45 × 31-mm, Type 2, poorly differentiated adenocarcinoma (pT4a, ly0, v1a), and the resected margin was negative. The patient was alive 2 years after surgery without apparent recurrence or other illness. In addition, her weight was maintained, together with her daily activity. CONCLUSION: Local resection of gastric cancer with LECS might be an option for the palliative treatment of patients who refuse radical resection of gastric cancer.

History and emerging trends in chemotherapy for gastric cancer.

Chemotherapy is indispensable for gastric cancer. For unresectable and/or recurrent gastric cancer, first-line chemotherapy consists of multidrug regimens including oral 5-FU agents such as S1/Xeloda and platinum preparations, as well as Trastuzumab, which is effective in HER2-positive cases. Second- and third-line chemotherapy regimens include taxanes, Ramucirumab (R-mab), and Nivolumab (N-mab), which have different mechanisms of action from first-line chemotherapy. R-mab is molecularly targeted to vascular endothelial growth factor receptor 2 in the host cells, but its indication is not conditional. For resectable gastric cancer, in Eastern countries, postoperative adjuvant chemotherapy has been successful, including S1, Docetaxel/S1 (DS), and Xeloda/Oxaliplatin (Xelox) regimens, whereas, in Western countries, the 5-FU/Leucovorin/Oxaliplatin/Docetaxel (FLOT) regimen was recently shown to be effective in the perioperative chemotherapy setting. Most recently, however, in Eastern countries, perioperative SOX was demonstrated to be effective in specific advanced gastric cancer. For stage IV gastric cancer, new therapeutic strategies have been proposed such as neoadjuvant chemotherapy and conversion surgery, and cures can be conditionally obtained. Recent genomic understanding of gastric cancer proposed a diversity of molecular targets by molecular profiling. Such optimized chemotherapy regimens, according to the specific clinical situations, have been rigorously established for the best survival of advanced gastric cancer.

Preoperative chemotherapy could modify recurrence patterns through postoperative complications in patients with gastric cancer.

PURPOSE: Postoperative infectious complications have a negative impact on survival outcomes in patients with gastric cancer. It is recently reported that preoperative chemotherapy may eliminate this negative impact. This study aimed to confirm whether preoperative chemotherapy can eliminate the negative impact of postoperative infectious complications (IC) on survival outcomes and elucidate the association between postoperative infectious complications and recurrence patterns. METHODS: We retrospectively reviewed data of 86 patients who received preoperative chemotherapy with docetaxel, cisplatin, and S-1 followed by R0 gastrectomy at the Kitasato University between 2006 and 2016. Patients who developed grade II or higher infectious complications during hospitalization were grouped into the IC group, while others were grouped into the non-IC (NIC) group. Survival outcomes and recurrence patterns were analyzed between the two groups. RESULTS: Infectious complications with Clavien-Dindo classification of grade II or higher were found in 12 patients (14.0%, IC group). The median observational period was 61 months. Overall survival and progression-free survival were similar in the IC and NIC groups. Recurrence occurred in 39 patients. The proportions of peritoneal and lymph node recurrences were not significantly different between the two groups. However, the proportion of distant metastasis in the IC group was significantly higher than that in NIC group (3/4 [75%] vs. 9/35 [17%], p = 0.04). CONCLUSIONS: Pathological stage after neoadjuvant therapy plays a stronger role in recurrence than postoperative complications. Lymph node and peritoneal metastasis may be suppressed by preoperative chemotherapy.

Prospective study to validate the clinical utility of DNA diagnosis of peritoneal fluid cytology test in gastric cancer.

The clinical efficacy of DNA cytology test (CY) in gastric cancer (GC) has been retrospectively proposed using cancer-specific methylation of cysteine dioxygenase type 1 (CDO1). We confirmed the clinical utility of DNA CY in a prospective cohort. Four hundred GC samples were prospectively collected for washing cytology (UMIN000026191), and detection of the DNA methylation of CDO1 was assessed by quantitative methylation-specific PCR in the sediments. Endpoint was defined as the match rate between conventional CY1 and DNA CY1 (diagnostic sensitivity), and the DNA CY0 rate (diagnostic specificity) in pStage IA. DNA CY1 was detected in 45 cases (12.5%), while CY1 was seen in 31 cases (8.6%) of 361 chemotherapy-naïve samples, where the sensitivity and specificity of the DNA CY in the peritoneal solutions were 74.2% and 96.5%, respectively. The DNA CY was positive for 3.5/0/4.9/11.4/58.8% in pStage IA/IB/II/III/IV, respectively (P < .01). In the multivariate analysis, DNA CY1 was independently correlated with pathological tumor depth (pT) (P = .0012), female gender (P = .0099), CY1 (P = .0135), P1 (P = .019), and carcinoembryonic antigen (CEA) (P = .036). The combination of DNA CY1 and P factor nearly all covered the potential peritoneal dissemination (P1 and/or CY1 and/or DNA CY1) (58/61:95.1%). DNA CY1 had a significantly poorer prognosis than DNA CY0 in GC patients (P < .0001). DNA CY1 detected by CDO1 promoter DNA methylation has a great value to detect minimal residual disease of the peritoneum in GC clinics, representing poor prognosis as a novel single DNA marker.

The incidences of metachronous multiple gastric cancer after various types of gastrectomy: analysis of data from a nationwide Japanese survey.

BACKGROUND: The incidence of metachronous multiple gastric cancer (MMGC) after gastrectomy remains unclear. This study evaluated the incidences of MMGC according to specific gastrectomy types, including pylorus-preserving gastrectomy (PPG), proximal gastrectomy (PG), and function-preserving gastrectomy (FPG), which was categorized as segmental gastrectomy and local resection. METHODS: We conducted a questionnaire survey of the Japanese Society for Gastro-Surgical Pathophysiology members, who were asked to report their institutional numbers of radical gastrectomy cases for cancer between 2003 and 2012. The cases were categorized according to whether the remnant stomach's status was followed for > 5 years, confirmation of MMGC, time to diagnosis, and treatment for MMGC. We calculated the "precise incidence" of MMGC by dividing the number of MMGC cases by the number of cases in which the status of remnant stomach was followed up for > 5 years. RESULTS: The responses identified 33,731 cases of gastrectomy. The precise incidences of MMGC were 2.35% after distal gastrectomy (DG), 3.01% after PPG, 6.28% after PG (p < 0.001), and 8.21% after FPG (p < 0.001). A substantial proportion of MMGCs (36.4%) was found at 5 years after the initial surgery. The rates of MMGC treatment using endoscopic submucosal dissection were 31% after DG, 28.6% after PPG, 50.8% after PG (p < 0.001), and 67.9% after FPG (p < 0.001). CONCLUSIONS: The incidence of MMGC was 2.4% after DG, and higher incidences were observed for larger stomach remnants. However, the proportion of cases in which MMGC could be treated using endoscopic submucosal dissection was significantly higher after PG and FPG than after DG.

Randomized study of prevention of gastrointestinal toxicities by nutritional support using an amino acid-rich elemental diet during chemotherapy in patients with esophageal cancer (KDOG 1101).

BACKGROUND: This randomized study was designed to evaluate the clinical effect of an elemental diet during chemotherapy in patients with esophageal cancer. METHODS: The inclusion criteria were as follows: (1) esophageal squamous cell carcinoma, (2) stage IB-IV, (3) schedule to receive docetaxel, cisplatin, and 5-fluorouracil (DCF chemotherapy), (4) 20-80 years old, (5) performance status of 0-2, (6) oral intake ability, and (7) written informed consent. Patients were divided into two groups: the elemental supplementary group and the non-supplementary group. Patients received ELENTAL® (160 g/day) orally 9 weeks after the start of chemotherapy. Primary endpoint was the incidence of grade 2 or higher gastrointestinal toxicity according to the Common Terminology Criteria for Adverse Events, version 4.0. Secondary endpoints were the incidence of all adverse events and the evaluation of nutritional status. RESULTS: Thirty-six patients in the elemental supplementary group and 35 patients in the non-supplementary group were included in the analysis. The incidence of grade 2 or higher gastrointestinal toxicity and all grade 3 or 4 adverse events did not differ significantly between the groups. In the elemental supplementary group, the body weight (p = 0.057), muscle mass (p = 0.056), and blood levels of transferrin (p = 0.009), total amino acids (p = 0.019), and essential amino acids (p = 0.006) tended to be maintained after chemotherapy. CONCLUSION: Nutritional support provided by an amino acid-rich elemental diet was ineffective for reducing the incidence of adverse events caused by DCF chemotherapy in patients with esophageal cancer.

Impact of preoperative chemotherapy as initial treatment for advanced gastric cancer with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) or localized peritoneal metastasis (P1a): a multi-institutional retrospective study.

BACKGROUND: Gastric cancer (GC) patients with peritoneal metastasis are defined as stage IV in the Japanese classification of GC. For patients with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) and/or localized peritoneal metastasis (P1a), gastrectomy followed by S1 monotherapy is one of the most widely accepted therapeutic strategy in Japan. This study investigated the efficacy of preoperative chemotherapy as initial treatment in GC patients with CY1 and/or P1a. METHODS: We retrospectively reviewed GC patients diagnosed with CY1 and/or P1a at 34 institutions in Japan between 2008 and 2012. Selection criteria were: adenocarcinoma, no distant metastasis except CY1 or P1a, and no prior treatment. The subjects were divided into an Initial-Chemotherapy group and an Initial-Surgery group, according to the initial treatment. RESULTS: A total of 824 patients were collected and 713 eligible patients were identified for this study. As the initial treatment, 150 patients received chemotherapy (Initial-Cx), and 563 patients underwent surgery (Initial-Sx). Initial-Cx regimens were cisplatin plus S1/docetaxel plus cisplatin plus S1/others (n = 90/37/23). Both overall survival (OS) and progression-free survival (PFS) were similar between the Initial-Cx and Initial-Sx groups (median OS 24.8 and 24.0 months, HR 1.07, 95% CI 0.87-1.3; median PFS 14.9 and 13.9 months, HR 1.04, 95% CI 0.85-1.27). The 5-year OS rates were 22.3% in the Initial-Cx group and 21.5% in the Initial-Sx group. CONCLUSIONS: Although, the preoperative chemotherapy did not show a survival benefit for GC patients with CY1 and/or P1a, initial-Cx showed favorable survival in patients who converted to P0 and CY0.

Robot-assisted minimally invasive esophagectomy for esophageal cancer: Meticulous surgery minimizing postoperative complications.

Minimally invasive esophagectomy (MIE) has been reported to reduce postoperative complications especially pulmonary complications and have equivalent long-term survival outcomes as compared to open esophagectomy. Robot-assisted minimally invasive esophagectomy (RAMIE) using da Vinci surgical system (Intuitive Surgical, Sunnyvale, USA) is rapidly gaining attention because it helps surgeons to perform meticulous surgical procedures. McKeown RAMIE has been preferably performed in East Asia where squamous cell carcinoma which lies in more proximal esophagus than adenocarcinoma is a predominant histological type of esophageal cancer. On the other hand, Ivor Lewis RAMIE has been preferably performed in the Western countries where adenocarcinoma including Barrett esophageal cancer is the most frequent histology. Average rates of postoperative complications have been reported to be lower in Ivor Lewis RAMIE than those in McKeown RAMIE. Ivor Lewis RAMIE may get more attention for thoracic esophageal cancer. The studies comparing RAMIE and MIE where recurrent nerve lymphadenectomy was thoroughly performed reported that the rate of recurrent nerve injury is lower in RAMIE than in MIE. Recurrent nerve injury leads to serious complications such as aspiration pneumonia. It seems highly probable that RAMIE is beneficial in performing recurrent nerve lymphadenectomy. Surgery for esophageal cancer will probably be more centralized in hospitals with surgical robots, which enable accurate lymph node dissection with less complications, leading to improved outcomes for patients with esophageal cancer. RAMIE might occupy an important position in surgery for esophageal cancer.

Postoperative pancreatic fistula after gastrectomy for gastric cancer.

Postoperative pancreatic fistula is one of the most severe complications after gastric cancer surgery, and can cause critical patient conditions leading to surgery-related death. Fortunately, the incidence of postoperative pancreatic fistula after gastrectomy seems to be decreasing with changes in operative procedures. The rate was reported at about 30% after open gastrectomy with Appleby's method in 1997, but lately has improved below 1% for robotic gastrectomy in 2019. For the diagnosis of postoperative pancreatic fistula, drain amylase concentration has been demonstrated to be beneficial and some reports have proposed the optimal cut-off values of drain amylase to predict major postoperative pancreatic fistula. There have been many reports identifying risk factors for postoperative pancreatic fistula, including overweight patients, pancreatic anatomy, blunt trauma from compression of the pancreas, and thermal injuries caused by the continuous use of energy devices. And importantly, laparoscopic gastrectomy has been shown to be more often associated with postoperative pancreatic fistula than open gastrectomy in the prospective national clinical database in Japan. Hence, further sophistication of surgical techniques to reduce pancreas compression would have great promise in reducing postoperative pancreatic fistula after laparoscopic gastrectomy.

Prediction of Efficacy of Postoperative Chemotherapy by DNA Methylation of CDO1 in Gastric Cancer.

BACKGROUND: CDO1 is a presumed tumor suppressor gene in human cancers, the expression of which is silenced by promoter DNA methylation. Moreover, CDO1 harbors functionally oncogenic aspects through modification of mitochondrial membrane potential. We recently proposed that this oncogenic feature allows for the prediction of the efficacy of postoperative chemotherapy in colon cancer. The present study aims to elucidate the efficacy of prediction of success of postoperative chemotherapy in advanced gastric cancer to improve the treatment strategy of patients. MATERIALS AND METHODS: Forced expression of CDO1 in gastric cancer cell lines was assessed using the JC-1 assay. Promoter DNA methylation was investigated in quantitative TaqMan methylation-specific polymerase chain reaction in 321 pathological stage II/III advanced gastric cancer cases treated by curative gastrectomy with or without postoperative chemotherapy. RESULTS: (1) Forced expression of CDO1 led to increased mitochondrial membrane potential, accompanied by augmented survival in gastric cancer cells under anaerobic conditions. These results suggest that CDO1-expressing cancer cells survive more easily in anaerobic lesions which are inaccessible to anticancer drugs. (2) Intriguingly, in cases with the highest CDO1 methylation (ranging from 15% to 40%), patients with postoperative chemotherapy showed significantly better survival than those with no postoperative chemotherapy. (3) A robust prognostic difference was observed that was explained by differential recurrences of distant metastasis (P = 0.0031), followed by lymph node (P = 0.0142) and peritoneal dissemination (P = 0.0472). CONCLUSIONS: The oncogenic aspects of CDO1 can be of use to determine patients with gastric cancer who will likely respond to treatment of invisible systemic dissemination by postoperative adjuvant chemotherapy.

Neoadjuvant chemotherapy plus surgery for high-risk advanced gastric cancer: long-term results of KDOG1001 trial.

PURPOSE: The purpose of this study is to evaluate the long-term survival outcomes of KDOG1001 trial after a minimum follow-up of 3 years. METHODS: Patients with bulky N2 lymph nodes, linitis plastica (type 4), or large ulcero-invasive-type tumors (type 3) received up to four 28-day cycles of DCS neoadjuvant chemotherapy (docetaxel at 40 mg/m2, cisplatin at 60 mg/m2 on day 1, and S-1 at 40 mg/m2 twice daily for 2 weeks) followed by gastrectomy with D2 lymphadenectomy plus adjuvant S-1 therapy for 1 year. The final preplanned analysis of long-term outcomes including overall survival and relapse-free survival was conducted after minimum follow-up of 3 years. This trial is registered with the University Hospital Medical Information Network Clinical Trials Registry, number UMIN 000003642, and has been completed. RESULTS: From May 2010 through January 2017, 40 patients were enrolled. All included patients underwent neoadjuvant chemotherapy with DCS followed by gastrectomy with D2 lymphadenectomy, and 32 (80%) completed adjuvant S-1 therapy for 1 year. After a median follow-up for surviving patients of 68 months at the last follow-up in January 2020, 3-year overall survival rate was 77.5% (95% confidence interval 62.1-87.9%), while 3-year relapse-free survival rate was 62.5% (95% confidence interval 46.8-76.0%). CONCLUSION: Neoadjuvant chemotherapy with 4 cycles of DCS followed by D2 gastrectomy plus adjuvant S-1 was associated with relatively good long-term oncologic outcomes for patients with the high-risk gastric cancer.