Feasibility of laparoscopic/robot-assisted surgery for Borrmann type 4 gastric cancer: a comparison study with conventional open surgery.

BACKGROUND: Laparoscopic surgery for early gastric cancer is regarded as a standard of care because of robust evidences obtained by several phase-III trials. Furthermore, the efficacy of laparoscopic radical surgery for advanced gastric cancer has been also reported. Meanwhile, the feasibility of laparoscopic surgery for Bormann type 4 gastric cancer, special type with unfavorable prognosis, remains unclear since excluded from eligibility of these trials. METHODS: This study included 100 patients with type 4 gastric cancer who underwent laparoscopic/robot-assisted (minimally invasive surgery (MIS) group; n = 32) or open (Open group; n = 68) curative surgery between 2008 and 2021. After propensity score matching, 30 patients in each group were extracted for analysis. Clinical data, including surgical and midterm survival outcomes, were retrospectively compared between the two groups. RESULTS: Incidences of postoperative complication (≥ Clavien-Dindo grade III) were recorded in 23.3% in the MIS group and 13.3% in the Open group, but no statistical significance was demonstrated (P = 0.50). The 3-year overall survival rate in the MIS group was better than that in the Open group (80.2% vs. 53.5%, log-rank, P = 0.03). The trend of recurrence site was similar. Multivariate analysis showed that adjuvant chemotherapy was an independent favorable prognostic factor (hazard ratio, 0.33, 95% confidence interval 0.11-0.93) for overall survival. MIS was indicated as a favorable prognostic factor (hazard ratio, 0.39, 95% confidence interval 0.39-1.07), but without statistical difference. CONCLUSION: While multidisciplinary treatment is mainstay of treatment because of the poor prognosis of this disease, minimally invasive surgery may play an important role in treatment if appropriate patient selection is done. Further analyses with larger sample size are necessary to reach a final conclusion regarding oncological efficacy.

Advantages of robotic gastrectomy for overweight patients with gastric cancer: a comparison study of robotic gastrectomy and conventional laparoscopic gastrectomy.

PURPOSE: A high body mass index (BMI) generally increases the risk of postoperative complications because of the intraperitoneal adipose tissue. Robotic gastrectomy (RG) decreases the surgical difficulty of conventional laparoscopic gastrectomy (LG) for these patients. We conducted the present study to identify the advantages of RG over LG for overweight patients. METHODS: We reviewed clinical data on patients who underwent either LG or RG at the National Cancer Center Hospital East between January, 2014 and May, 2022. RESULTS: The 1298 patients eligible patients were divided into a non-overweight cohort (n = 996) (LG, n = 818; RG, n = 178) and an overweight cohort (n = 302) (LG, n = 250; RG, n = 52) according to a BMI cut-off of 25 kg/m2. In the overweight cohort, the RG group had a lower incidence of grade ≥ III postoperative complications (0.0 vs. 8.8%, p = 0.01) and grade ≥ II postoperative complications (11.5 vs. 22.0%, p = 0.12) than the LG group. Multivariate analysis identified that RG was significantly associated with a lower incidence of grade ≥ II postoperative complications in the overweight cohort (odds ratio, 0.33; 95% confidence interval, 0.12-0.87; p = 0.02). CONCLUSIONS: RG may reduce the risk of postoperative complications, compared with conventional LG, in overweight patients.

Impact of postoperative intra-abdominal infectious complications on survival outcomes in patients with gastric cancer who underwent laparoscopic surgery.

BACKGROUND: Postoperative intra-abdominal infection is known to adversely affect survival outcomes in patients with gastric cancer; however, previous reports have investigated this complication only in open surgery. This adverse effect is expected to be weakened by less invasive surgery, such as a laparoscopic approach, by way of maintaining immune function. METHODS: This study included 1223 patients with gastric cancer who underwent open (n = 439) or laparoscopic (n = 784) curative surgery between 2010 and 2015. For each approach, patients were divided into two groups based on presence or absence of postoperative intra-abdominal infection of Clavien-Dindo grade II or higher (C-group and NC-group, respectively). Survival outcomes were compared in propensity-matched cohorts to evaluate the impact of the complication. RESULTS: The incidences of Clavien-Dindo ≥ grade II postoperative intra-abdominal infectious complications were 9.7% (43/439) in open surgery and 9.8% (70/714) in laparoscopic surgery. After propensity score matching, 86 patients in open surgery and 138 in laparoscopic surgery were extracted for analysis. The 5-year overall survival rate in the open C-group (n = 43) was worse than that in the open NC-group (n = 43) but with no significant difference (70.9% vs. 82.8%, log-rank P = 0.18). The 5-year overall survival rates were equivalent between the laparoscopic C-group (n = 69) and the laparoscopic NC-group (n = 69) (90.5% vs. 90.4%, log-rank P = 0.99). CONCLUSION: In general, postoperative intra-abdominal infection adversely affects survival outcomes; however, its impact may be weakened by less invasive surgery. Further evaluation using larger datasets is necessary before reaching definitive conclusions.

The Significance of Staging Laparoscopy in Detection of Radiologically Occult Peritoneal Carcinomatosis in Gastric Cancer With Gastric Outlet Obstruction: Consideration of The Optimal Treatment Approach.

BACKGROUND/AIM: Gastric cancer with gastric outlet obstruction (GOO) is generally found at an advanced stage and with an unfavorable prognosis. This study was performed to examine the prevalence of radiologically occult peritoneal carcinomatosis in GOO and determine the optimal treatment strategy. PATIENTS AND METHODS: This single-center study was a retrospective review of the clinical data of 186 patients with locally advanced gastric cancer at the distal stomach who underwent surgery from 2008 to 2016. These patients were divided into two groups according to the presence or absence of GOO due to cancer progression: With GOO (n=71) and without GOO (n=115). RESULTS: The incidence of peritoneal carcinomatosis [with macroscopic peritoneal deposits (P1)/positive peritoneal cytology (CY1)] detected at laparotomy/laparoscopy was significantly higher in the group with GOO than in the group without (32.4% vs. 9.6%, p<0.01). The R0 resection rate was lower in the group with GOO (62.0% vs. 87.0%, p<0.01). The 5-year overall survival rate was also lower in the group with GOO (43.9% vs. 68.5%, p<0.01). However, in the subset of patients who underwent R0 surgery, the 5-year rates were similar for the two groups (67.4% vs. 73.1%, p=0.91). The multivariable analysis showed that a type 3 tumor appearance (odds ratio=3.66) and presence of GOO (odds ratio=2.87) were predictors of peritoneal carcinomatosis. CONCLUSION: The prevalence of radiologically occult peritoneal carcinomatosis in gastric cancer with GOO exceeded 30%. Staging laparoscopy (gastrojejunal bypass, if needed) should be performed to determine the optimal treatment plan.

Reduction in postoperative complications by robotic surgery: a case-control study of robotic versus conventional laparoscopic surgery for gastric cancer.

BACKGROUND: Robotic gastrectomy (RG) is being increasingly performed globally; it is considered an evolved type of conventional laparoscopic surgery with excellent dexterity and precision, but higher costs and longer operation time. Thus, there is a need to identify the benefits from RG and its specific candidates. METHODS: This retrospective study analyzed data from a prospectively collected clinical database at our center. Data of patients with primary gastric cancer undergoing either robotic or laparoscopic radical gastrectomy from June 2014 to June 2020 were reviewed. Surgical outcomes were compared between the two groups, and multivariable analyses were performed to elucidate the relevant factors for postoperative complications in several subgroups. RESULTS: A total of 1172 patients were divided into those who underwent RG (n = 152) and those who underwent laparoscopic gastrectomy (LG) (n = 1020). Baseline characteristics were similar in the two groups, except the RG group included more patients undergoing total/proximal gastrectomy (TG/PG) and patients at clinical stage III. Compared with the LG group, the RG group had lower incidences of postoperative complications ≥ Clavien-Dindo grade III (2/152 (1.3%) versus 72/1020 (7.1%); P = 0.004), and intraabdominal complications ≥ grade II (6/152 (3.9%) versus 119/1020 (11.7%); P = 0.004). Multivariable analysis revealed that RG was a significant relevant factor for reducing overall postoperative complications (≥ grade III) (odds ratio (OR) 0.16, P = 0.013), and intraabdominal complications (≥ grade II) (OR 0.29, P = 0.002). Subgroup analyses demonstrated that this tendency was enhanced in patients undergoing TG/PG (OR 0.29, P = 0.021) or at clinical stage II/III (OR 0.10, P = 0.027). CONCLUSIONS: RG reduces the incidence of postoperative complications compared with conventional LG and this tendency may be enhanced in technically complicated procedures with demanding anastomosis or D2 lymphadenectomy. Patients requiring such procedures would most benefit from RG.

Is splenic hilar lymph node dissection necessary for proximal gastric cancer surgery?

Advanced proximal gastric cancer sometimes metastasizes to the splenic hilar lymph nodes (No. 10 LN). Total gastrectomy combined with splenectomy is performed for complete removal of the No. 10 LN and was historically a standard procedure in Japan. However, splenectomy is associated with several disadvantages for patients, such as increased postoperative morbidity, risk of thrombogenic disease, fatal infection from encapsulated bacteria, and the development of other types of cancer in the long term because of loss of immune function. Therefore, splenectomy should only be performed when its estimated oncological effect exceeds such disadvantages. A Japanese randomized controlled trial (JCOG0110) clearly demonstrated that prophylactic splenectomy is not necessary unless the tumor has invaded the greater curvature; thus, splenectomy is no longer routinely performed in Japan. However, several retrospective studies have shown a comparatively high incidence of No. 10 LN metastasis and therapeutic value from LN dissection at that station in the tumors invading the greater curvature. Similar tendencies have also been reported in type 4 or remnant gastric cancer involving the greater curvature. In view of these facts, No. 10 LN dissection is presently recommended for such patients; however, robust evidence is lacking. In recent years, laparoscopic/robotic spleen-preserving splenic hilar dissection utilizing augmented visualization without pancreatic mobilization has been developed. This procedure is expected to replace prophylactic splenectomy and provide an equal oncological effect with lower morbidity. In Japan, a prospective phase-II study (JCOG1809) is currently ongoing to investigate the safety and feasibility of this procedure.

Pancreatic Juice Exosomal MicroRNAs as Biomarkers for Detection of Pancreatic Ductal Adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a lethal neoplasm because of difficulties in early detection. Several studies have recently suggested that exosomes may have potential as novel biomarkers. This study aimed to isolate exosomes from pancreatic juice and to investigate whether exosomal microRNAs (ex-miRs) could be used as biomarkers for PDAC. METHODS: Pancreatic juice was collected from patients with PDAC and chronic pancreatitis (CP) by endoscopic retrograde pancreatography. Exosomes were extracted by ultracentrifugation. The presence of exosomes was confirmed by electron microscopy and Western blotting using anti-CD63, -CD81, and -TSG101 antibodies. Relative levels of ex-miR-21 and ex-miR-155 were quantified and compared between PDAC and CP patients. RESULTS: A total of 35 pancreatic juice samples (27 PDAC and 8 CP) were collected. Relative levels of both ex-miR-21 and ex-miR-155 were significantly higher in PDAC patients compared with CP patients (p < 0.001 and p = 0.008, respectively). By contrast, no significant difference was apparent in relative levels of miR-21 and miR-155 in whole pancreatic juice from PDAC patients compared with CP patients (p = 0.08 and p = 0.61, respectively). Ex-miR-21 and ex-miR-155 levels discriminated PDAC patients from CP patients with area under the curve values of 0.90 and 0.89, respectively. The accuracies of ex-miR-21 levels, ex-miR-155 levels, and pancreatic juice cytology were 83%, 89%, and 74%, respectively. When combining the results of ex-miR profiling with pancreatic juice cytology, the accuracy was improved to 91%. CONCLUSIONS: We successfully extracted exosomes from pancreatic juice. Ex-miRs, including ex-miR-21 and ex-miR-155, in pancreatic juice may be developed as biomarkers for PDAC.

Neutrophil-to-lymphocyte ratio and mural nodule height as predictive factors for malignant intraductal papillary mucinous neoplasms.

BACKGROUND: Accurate preoperative prediction for malignant IPMN is still challenging. The aim of this study was to investigate the validity of neutrophil-to-lymphocyte ratio (NLR) and mural nodule height (MNH) for predicting malignant intraductal papillary mucinous neoplasm (IPMN). METHODS: The medical records of 60 patients who underwent pancreatectomy for IPMN were retrospectively reviewed. RESULTS: NLR tended to be higher in malignant IPMN (median: 2.23) than in benign IPMN (median: 2.04; p = .14). MNH was significantly greater in malignant IPMN (median: 16 mm) than in benign IPMN (median: 8 mm; p < .01). The optimal cutoff values for the NLR and MNH were 3.60 and 11 mm, respectively. The sensitivity and specificity of NLR ≥3.60 for predicting malignant IPMN were 40% and 93%, and those of MNH ≥11 mm were 73% and 77%, respectively. Univariate analysis revealed that NLR ≥3.60 (p < .01) and MNH ≥11 mm (p < .01) were significant predictive factors. On multivariate analysis, enhanced solid component was identified as an independent factor, but NLR ≥3.60 and MNH ≥11 mm were not. CONCLUSIONS: NLR and MNH are suboptimal tests in predicting malignant IPMN; however, they can be useful to assist in clinical decision-making.

Effect of postoperative major complications on prognosis after pancreatectomy for pancreatic cancer: a retrospective review.

PURPOSE: To investigate the impact of postoperative complications on survival after curative resection for pancreatic cancer. METHODS: We reviewed retrospectively the medical records of 122 patients who underwent curative R0 resection for pancreatic cancer. Major complications included pancreatic fistula and hemorrhage of grade B or C according to the International Study Group of Pancreatic Fistula or Surgery criteria, and other complications of grade ≥III according to the Clavien-Dindo classification. RESULTS: Thirty-eight patients (31 %) suffered major postoperative complications and 40 patients (33 %) suffered minor complications only. Univariate survival analysis showed that patients with major complications had a significantly worse prognosis than those without major complications, with regard to recurrence-free survival (RFS) (P < 0.01) and overall survival (OS) (P < 0.01), whereas minor complications did not affect survival. Major complications significantly inhibited or delayed adjuvant chemotherapy. Multivariate survival analysis showed that the absence of postoperative major complications was an independent favorable factor for RFS (hazard ratio 0.48; 95 % confidence interval: 0.28-0.85) and OS (hazard ratio 0.47; 95 % confidence interval 0.27-0.81). CONCLUSIONS: Postoperative major complications after pancreatectomy for pancreatic cancer affect the prognosis.