Hayato Omori

Robotic surgery for gastric cancer

Laparoscopic gastrectomy is a widely used minimally invasive surgery for gastric cancer. However, skillful techniques are required to perform lymph node dissection using straight shaped forceps, particularly for D2 dissection. Robotic surgery using the da Vinci surgical system is anticipated to be a powerful tool for performing difficult techniques using high-resolution three-dimensional (3D) images and the EndoWrist equipped with seven degrees of freedom. Attempts are being made to apply robotic surgery in gastrectomy procedures mainly in Japan, South Korea, and Europe. Although definite superiority to laparoscopic gastrectomy is yet to be proven, robotic surgery has been reported to have a shorter learning curve and offer more precise dissection for total gastrectomy. Hence, its oncological efficacy needs to be verified in a clinical trial.

Feasibility of Laparoscopic Distal Gastrectomy for Stage I Gastric Cancer in Patients Outside of Clinical Trials

BackgroundRandomized controlled trials, including the Japan Clinical Oncology Group (JCOG) 0912 trial, have shown the safety of laparoscopy-assisted distal gastrectomy (LADG) for select healthy patients. It is unclear whether LADG is feasible in patients who do not meet trial eligibility criteria.MethodsThe present study retrospectively reviewed 547 patients with clinical stage I gastric cancer who underwent distal or pylorus-preserving gastrectomy. Of these, 185 were identified as not fulfilling the eligibility criteria of JCOG 0912; the short-term surgical outcomes between LADG and open distal gastrectomy (ODG) were compared in this group before and after propensity score matching.ResultsPatients who were not eligible for inclusion in the trial comprised 33.8% of the total. After matching, there were 59 patients each in the LADG and ODG groups, with an improved balance of confounding factors between the two groups. LADG was associated with significantly longer operation time, less blood loss, and shorter postoperative hospital stay than ODG. The rate of overall postoperative complications of Clavien–Dindo Grade II or higher did not differ significantly between the LADG and ODG groups (23.7 vs. 18.6%, respectively; p = 0.653). The incidence of pneumonia (6.8 vs. 5.1%), intra-abdominal infectious complications (5.1 vs. 3.4%), and stasis syndrome (5.1 vs. 3.4%) was also comparable between the two groups.ConclusionLADG was as safe as ODG in patients who did not meet the eligibility criteria of JCOG 0912. LADG could be a standard treatment option for patients with stage I gastric cancer, regardless of their general condition.

Impact of extra-nodal metastasis on survival in gastric cancer patients with lymph node involvement.

57Background: Extra-nodal metastasis (ENM) is defined as a tumor nodule without lymph node structure, and distinguished from lymph node metastasis by histological findings. Despite the possible difference in metastatic mechanism, both are counted as metastasized lymph nodes according to the 3rd English edition of Japanese Classification of Gastric Carcinoma, and thus the prognostic value of ENM remains unclear. The aim of this study was to clarify the clinicopathogical characteristics and prognostic impact of ENM in gastric cancer patients with lymph node involvement. Methods: This study included 388 patients who underwent curative gastrectomy for primary gastric cancer between January 2009 and August 2013. A total of 2093 pathologically positive tumor nodules, including both metastatic lymph nodes and ENM, were examined. Clinicopathological characteristics and survival outcomes were compared between an ENM positive (ENMP) group (95 patients) and an ENM negative (ENMN) group (293 patients). In addition, m...

Impact of sarcopenia on short- and long-term outcomes in patients with gastric cancer.

19 Background: Depletion of skeletal muscle in aged people (sarcopenia) regarded as a poor prognostic factor in various cancers. The aim of this study was to assess the impact of preoperative sarcopenia on postoperative short- and long-term outcomes in patients with gastric cancer underwent curative resection. Methods: A total of 881 patients who underwent R0 resection for gastric cancer aged 65 or older between June 2003 and March 2011 were included in this study. Muscle mass was assessed by measuring percentage of arm muscle area (%AMA). Preoperative sarcopenia was defined as aged 65 or older, %AMA <80%, and decline in grip strength ( <25kg in men, <20kg in women), according to algorithm suggested by European Working Group on Sarcopenia in Older People (EWGSOP) with slight modification. Relationship between sarcopenia and short- and long-term outcomes were evaluated using uni- and multi-variate analysis. Results: Of 881 patients, sarcopenia was diagnosed in 62 patients (7.0%). Incidence of sarcopenia wa...

Role of palliative resection in patients with incurable advanced gastric cancer unfit for chemotherapy.

114 Background: Recently, REGATTA trial showed that debulking surgeries followed by chemotherapy did not improve survival outcomes compared to chemotherapy alone for incurable advanced gastric cancer (AGC). Therefore, the standard treatment for incurable AGC without emergent symptom is not gastrectomy plus chemotherapy but chemotherapy alone. However, in patients who are unfit for chemotherapy due to poor performance status (PS), age, or comorbid chronic diseases, the role of palliative gastrectomy remains controversial. The aim of this study is to determine the role of palliative resection in patients with incurable AGC unfit for chemotherapy. Methods: Two hundred and twelve gastric cancer patients having any cause of incurable factors and underwent palliative gastrectomy or bypass operation between November 2002 and December 2014 were enrolled. Of these 212 patients, 64 patients who did not receive any chemotherapy were divided into two groups; Gastrectomy group with 45 patients who underwent palliative...

Histological evaluation of tumor response in metastatic lymph node after preoperative chemotherapy for gastric cancer.

51 Background: Preoperative chemotherapy is thought to be an option for treatment of advanced gastric cancer. However, optimal predictive marker for survival of preoperative chemotherapy had not yet been established. Histological response is thought to be a good candidate of predictive marker, however, it had been determined only in primary tumor, not in the metastatic lymph node. The aim of this study is to evaluate the role of histological response in metastatic lymph node on the survival in patients received preoperative chemotherapy for advanced gastric cancer. Methods: A total of 38 patients who underwent curative resection after preoperative chemotherapy from were included. For histological evaluation in lymph node, we determined it as positive if remaining viable tumor cells are less than 30% of the tumor area at one or more of the resected metastatic lymph nodes. We also evaluated histological response in primary tumor according to the Japanese Gastric Cancer Classification. Results: 21 patients r...