Short-term outcomes of a multicentre randomized clinical trial comparing laparoscopic pylorus-preserving gastrectomy with laparoscopic distal gastrectomy for gastric cancer (the KLASS-04 trial).

BACKGROUND: There remain concerns about the safety and functional benefit of laparoscopic pylorus-preserving gastrectomy (LPPG) compared with laparoscopic distal gastrectomy (LDG). This study evaluated short-term outcomes of a randomized clinical trial (RCT) comparing LPPG with LDG for gastric cancer. METHODS: The Korean Laparoendoscopic Gastrointestinal Surgery Study (KLASS)-04 trial was an investigator-initiated, open-label, parallel-assigned, superiority, multicentre RCT in Korea. Patients with cT1N0M0 cancer located in the middle third of the stomach at least 5 cm from the pylorus were randomized to undergo LPPG or LDG. Participants, care givers and those assessing the outcomes were not blinded to group assignment. Outcomes were 30-day postoperative morbidity rate and death at 90 days. RESULTS: Some 256 patients from nine institutions were randomized (LPPG 129 patients, LDG 127 patients) between July 2015 and July 2017 and outcomes for 253 patients were analysed. Postoperative complications within 30 days were seen in 19.3 and 15.5 per cent in the LPPG and LDG groups respectively (P = 0·419). Postoperative pyloric stenosis was observed in nine (7.2 per cent) and two (1·5 per cent) patients in the LPPG and LDG groups (P = 0·026) respectively. In multivariable analysis higher BMI was a risk factor for postoperative complications (odds ratio 1·17, 95 per cent c.i. 1·04 to 1·32; P = 0·011). Death at 90 days was zero in both groups. CONCLUSION: Postoperative complications and mortality was comparable in patients undergoing LPPG and LDG. Registration number: NCT02595086 (http://www.clinicaltrials.gov).

Who may benefit from robotic gastrectomy?: A subgroup analysis of multicenter prospective comparative study data on robotic versus laparoscopic gastrectomy.

AIMS: Robotic gastrectomy for gastric cancer has been proven to be a feasible and safe minimally invasive procedure. However, our previous multicenter prospective study indicated that robotic gastrectomy is not superior to laparoscopic gastrectomy. This study aimed to identify which subgroups of patients would benefit from robotic gastrectomy rather than from conventional laparoscopic gastrectomy. METHODS: A prospective multicenter comparative study comparing laparoscopic and robotic gastrectomy was previously conducted. We divided the patients into subgroups according to obesity, type of gastrectomy performed, and extent of lymph node dissection. Surgical outcomes were compared between the robotic and laparoscopic groups in each subgroup. RESULTS: A total of 434 patients were enrolled into the robotic (n = 223) and laparoscopic (n = 211) surgery groups. According to obesity and gastrectomy type, there was no difference in the estimated blood loss (EBL), number of retrieved lymph nodes, complication rate, open conversion rate, and the length of hospital stay between the robotic and laparoscopic groups. According to the extent of lymph node dissection, the robotic group showed a significantly lower EBL than did the laparoscopic group after D2 dissection (P = 0.021), while there was no difference in EBL in patients that did not undergo D2 dissection (P = 0.365). CONCLUSION: Patients with gastric cancer undergoing D2 lymph node dissection can benefit from less blood loss when a robotic surgery system is used.

PPP1R1B-STARD3 chimeric fusion transcript in human gastric cancer promotes tumorigenesis through activation of PI3K/AKT signaling.

Fusion genes act as potent oncogenes, resulting from chromosomal rearrangements or abnormal transcription in many human cancers. Although multiple gastric cancer genomes have been sequenced, the driving recurrent gene fusions have not been well characterized. Here, we used paired-end transcriptome sequencing to identify novel gene fusions in 18 human gastric cancer cell lines and 18 pairs of primary human gastric cancer tissues and their adjacent normal tissues. Multiple samples revealed expression of PPP1R1B-STARD3 fusion transcript. The presence of PPP1R1B-STARD3 correlated with elevated levels of PPP1R1B mRNA. PPP1R1B-STARD3 fusion transcript was detected in 21.3% of primary human gastric cancers but not in adjacent matched normal gastric tissues. Based on reverse transcription PCR analysis of DNA, unlike other fusions described in gastric cancer, the PPP1R1B-STARD3 appears to be generated by RNA processing without chromosomal rearrangement. Overexpression of PPP1R1B-STARD3 in MKN-28 significantly increased cell proliferation and colony formation. This increased proliferation was mediated by activation of phosphatidylinositol-3-kinase (PI3K)/AKT signaling. Furthermore, expression of PPP1R1B-STARD3 fusion transcript enhanced the tumor growth of MKN-28 cells in athymic nude mice. These findings show that PPP1R1B-STARD3 fusion transcript has a key role in subsets of gastric cancers through the activation of PI3K/AKT signaling.

Stomach hanging technique using gauze during laparoscopic gastrectomy.

INTRODUCTION: Lifting the stomach using laparoscopic instruments during laparoscopic gastrectomy is difficult and increases the risk of crushing the tumor. In this study, we present a stomach hanging technique using gauze pieces that reduces the risk to the tumor. MATERIALS AND SURGICAL TECHNIQUE: After a partial omentectomy and the opening of the lesser sac, the antrum was wrapped with a 15-20-cm gauze piece. Next, a straight needle with 2-0 monofilament suture material pierced the abdominal cavity through the right subcostal area on the mid-clavicular line, and the gauze was then sutured twice in a figure of eight manner. The needle was removed percutaneously through the right middle quadrant of the abdomen. Another suture was applied to wrap the left side of the stomach. The stomach was easily lifted and positioned by pulling the four suture strings in different directions. After the suture materials were fastened to the abdominal wall using hemostat forceps, the surgical field was sufficiently exposed, facilitating lymph node dissection on the superior surface of the pancreas. This method freed the assistant from holding the stomach and enabled this individual to assist the operation in other ways. DISCUSSION: This stomach lifting technique using gauze is a good option for exposing the surgical field, enables the assistant to perform other tasks, and reduces the risk of crushing the tumor during laparoscopic gastrectomy.

Validation of limited lymphadenectomy for lower-third gastric cancer based on depth of tumour invasion.

BACKGROUND: This study aimed to determine the appropriate extent of lymph node (LN) dissection in gastric cancer by analysing LN metastasis patterns from prospectively collected topographical data on nodal status at Seoul National University Hospital, Korea. METHODS: The metastasis rate for each LN station was analysed according to the depth of tumour invasion in patients with primary lower-third gastric cancer who underwent curative gastrectomy. The Maruyama Index of unresected disease (MI) was calculated using the WinEstimate(®) program with simulation of various extents of LN dissection. RESULTS: LN metastasis in mucosal cancer was rare; 2·6 per cent of patients had a MI of more than 5 with simulation of D1 plus station 7 dissection, whereas 0·9 per cent had a MI above 5 with D1 plus stations 7 and 8a. In submucosal cancer, 3·3 per cent of tumours metastasized to level 2 LN stations outside the range of D1 plus stations 7, 8a and 9. The proportion of patients with a MI above 5 was 9·0 per cent with D1 plus stations 7, 8a and 9 dissection. The nodal metastasis rate was higher at level 1 and 2 for muscularis propria or deeper cancers. CONCLUSION: D1 dissection plus stations 7 and 8a for mucosal cancer, and D2 dissection for cancers of the muscularis propria or deeper seems appropriate. For submucosal cancer, an expanded dissection to the D2 level should be considered to ensure complete removal of metastatic LNs.

Iron monosulfide as a scavenger for dissolved hexavalent chromium and cadmium.

Iron sulfide minerals are common components of soil/sedimentary environments. Reactions near the surfaces of iron sulfides play important roles in metal retention, mobility, and bioavailability. A series of batch experiments was conducted to study the removal of aqueous chromium and cadmium by iron monosulfide. Hexavalent chromium was reduced to Cr(III) by iron monosulfide with simultaneous precipitation of chromium and iron oxyhydroxide. In contrast to chromium, the primary retention mechanism of cadmium by iron monosulfide was lattice exchange. Surface adsorption to iron monosulfide and precipitation with sulfide on the iron monosulfide surface also contributed to the removal of aqueous cadmium. New phases of both chromium and cadmium were confirmed with transmission electron microscopy. The solution pH was an important factor in this research; it can change particle surface charge and metal species, hence affecting the removal of chromium, but not cadmium. Ferrous ions without FeS exhibited less Cr(VI) removal than with FeS, which might be owing to sulfides from FeS and the existence of the solid phase. Iron monosulfide exhibited higher removal efficiency for chromium and cadmium than zero valent iron and other iron oxide minerals, and the synergistic effect of ferrous iron and sulfide appeared to cause this result.