Minimally invasive technique for gastric GIST at challenging locations: single incision surgical gastroscopy

Organ sparing resection of gastrointestinal stromal tumors (GISTs) located in the proximal stomach or esophagogastric junction can be challenging, resulting in proximal or total gastrectomy to facilitate a radical resection without tumor spill. We developed and evaluated a single incision surgical gastroscopy (SISG) procedure to provide a technically feasible alternative for the removal of gastric GISTs at these challenging locations. We developed an endoluminal resection of gastric GISTs through a small single abdominal incision and longitudinal ventral gastrotomy. Patients with a proximal tumor location, in whom a wedge resection was deemed challenging on pre-operative investigation were included in the current series. Safety, short-term oncological and surgical outcome were evaluated. We performed SISG in six consecutive patients with histopathological proven or suspected gastric GIST. In all patients, the procedure was performed successfully with no tumor rupture. The mean operative time was 61 min and there were no significant complications. Pathological examination showed a microscopically radical resection in all patients. Single incision surgical gastroscopy is a feasible technique with excellent short-term oncological and surgical outcomes. This technique serves as a good alternative for complicated resections for gastric GISTs at challenging locations.

Molecular profiles of response to neoadjuvant chemoradiotherapy in oesophageal cancers to develop personalized treatment strategies

Identification of molecular predictive markers of response to neoadjuvant chemoradiation could aid clinical decision‐making in patients with localized oesophageal cancer. Therefore, we subjected pretreatment biopsies of 75 adenocarcinoma (OAC) and 16 squamous cell carcinoma (OSCC) patients to targeted next‐generation DNA sequencing, as well as biopsies of 85 OAC and 20 OSCC patients to promoter methylation analysis of eight GI‐specific genes, and subsequently searched for associations with histopathological response and disease‐free (DFS) and overall survival (OS). Thereby, we found that in OAC, CSMD1 deletion (8%) and ETV4 amplification (5%) were associated with a favourable histopathological response, whereas SMURF1 amplification (5%) and SMARCA4 mutation (7%) were associated with an unfavourable histopathological response. KRAS (15%) and GATA4 (7%) amplification were associated with shorter OS. In OSCC, TP63 amplification (25%) and TFPI2 (10%) gene promoter methylation were associated with an unfavourable histopathological response and shorter DFS (TP63) and OS (TFPI2), whereas CDKN2A deletion (38%) was associated with prolonged OS. In conclusion, this study identified candidate genetic biomarkers associated with response to neoadjuvant chemoradiotherapy in patients with localized oesophageal cancer.

A new Low Molecular Weight Heparinoid Org 10172 as Anticoagulant in Hemodialysis

A low molecular weight heparinoid (Org 10172) was compared with unfractionated heparin in 36 patients on chronic hemodialysis in an open randomized cross-over study with three anti-coagulant treatment regimens for a single hemodialysis session. The anti-coagulant regimens were: a) standard heparin (3250–4750 I.U. heparin at start of hemodialysis followed by continuous infusion of 2000–2700 I.U. per hour); b) Org 10172 administered as a single intravenous bolus of 2400 anti-Xa units at start of dialysis; c) Org 10172 administered as a single bolus of 3200 anti-Xa units at start of dialysis. Plasma anti-Xa activity during hemodialysis was highest in regimen; d) and significantly lower when heparin was used. Mean β-thromboglobulin concentrations changed to the same extent in the three groups. Plasma platelet factor 4 concentrations were higher after the use of heparin. The extracorporeal circuit was maintained patent in all groups; the volume of blood retained in the dialyzers did not differ markedly. Org 10172 proved safe and its anticoagulant effect was sufficient at the dose levels studied.

Biobanking of fresh-frozen endoscopic biopsy specimens from esophageal adenocarcinoma

The process of preparing endoscopic esophageal adenocarcinoma samples for next-generation DNA/RNA sequencing is poorly described. Therefore, we assessed the feasibility and pitfalls of preparing esophageal adenocarcinoma endoscopic biopsies toward DNA/RNA samples suitable for next-generation sequencing. In this prospective study, four tumor biopsy samples were collected from consecutive esophageal cancer patients during esophagogastroduodenoscopy and fresh-frozen in liquid nitrogen. DNA and RNA were isolated from samples with a tumor percentage of at least 50%. For next-generation sequencing, double-stranded DNA (dsDNA) is required and high-quality RNA preferred. The quantity dsDNA and RNA quantity and quality were assessed with the Nanodrop 2000 spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA) and Agilent 2100 Bioanalyzer (Agilent, Santa Clara, CA, USA). Biopsy samples of 69 consecutive patients with esophageal adenocarcinoma were included. In five patients (7%), the tumor percentage was less than 50% in all four biopsies. Using a protocol allowing simultaneous DNA and RNA isolation, the median dsDNA yield was 2.4 μg (range 0.1-12.0 μg) and the median RNA yield was 0.5 μg (range 0.01-2.05 μg). The median RNA integrity number of samples that were fresh-frozen within 30 minutes after sampling was 6.7 (range 4.2-8.9) compared with 2.5 (1.8-4.5) for samples that were fresh-frozen after 2 hours. The results from this study show that obtaining dsDNA and RNA for next-generation sequencing from endoscopic esophageal adenocarcinoma samples is feasible. Tumor percentage and dsDNA/RNA yield and quality emphasize the need for sampling multiple biopsies and minimizing the delay before fresh-freezing.

Surgical treatment results of intestinal and diffuse type gastric cancer. Implications for a differentiated therapeutic approach?

AIM

To study the outcome of patients who were surgically treated for primary gastric cancer with specific attention to differences in treatment results for intestinal and diffuse type tumours.

METHODS

All patients who underwent a potentially curative gastric resection between 1995 and 2011 in our institute were included. Patient, tumour and treatment characteristics were obtained retrospectively. Binary logistic and Cox regression models were used for multivariate analysis.

RESULTS

A consecutive series of 132 patients was included. Median follow-up was 53 months. There were no significant differences between patients with intestinal (N = 62) versus diffuse type (N = 70) gastric cancer with regard to the proportion of patients who underwent (neo)adjuvant treatment. Postoperative mortality was 2%. Pathological T- and N-stage were significantly more advanced for patients with diffuse type tumours. There was a significant difference in the percentage of microscopically irradical resections (2% versus 24%, p < 0.001) and median overall survival (129 versus 17 months, p < 0.001) between patients with intestinal type tumours and those with diffuse type tumours. On multivariate analysis, diffuse type histology was the only factor significantly associated with an R1 resection. In a multivariate Cox regression model, diffuse type histology was a significant adverse prognostic factor for overall survival.

CONCLUSIONS

Striking differences were found between patients with diffuse type tumours and those with intestinal type tumours. These differences call for a differentiated approach in the potentially curative treatment of these two tumour types.

A new low molecular weight heparinoid Org 10172 as anticoagulant in hemodialysis

A low molecular weight heparinoid (Org 10172) was compared with unfractionated heparin in 36 patients on chronic hemodialysis in an open randomized cross-over study with three anti-coagulant treatment regimens for a single hemodialysis session. The anti-coagulant regimens were: a) standard heparin (3250-4750 I.U. heparin at start of hemodialysis followed by continuous infusion of 2000-2700 I.U. per hour); b) Org 10172 administered as a single intravenous bolus of 2400 anti-Xa units at start of dialysis; c) Org 10172 administered as a single bolus of 3200 anti-Xa units at start of dialysis. Plasma anti-Xa activity during hemodialysis was highest in regimen; d) and significantly lower when heparin was used. Mean beta-thromboglobulin concentrations changed to the same extent in the three groups. Plasma platelet factor 4 concentrations were higher after the use of heparin. The extracorporeal circuit was maintained patent in all groups; the volume of blood retained in the dialyzers did not differ markedly. Org 10172 proved safe and its anticoagulant effect was sufficient at the dose levels studied.

Mucosal uptake, mucosal transfer and retention of a therapeutic dose of iron

The absorption of a pharmacological dose of iron was assessed by determination of mucosal uptake, mucosal transfer and retention of 33 mg (Fe(II) as ferrous sulphate and ferrous ascorbate. 20 subjects were studed in a cross-over trial, 11 with normal iron stores and 9 with iron deficiency according to the serum ferritin concentrations. The activity of 59Fe and 51Cr (administered as a non-absorbable indicator) was measured by whole-body counting. There was no difference in absorption between the two iron compounds in normal subjects. Absorption of ferrous ascorbate averaged 52% higher than ferrous sulphate in subjects with iron deficiency. The difference was the result of higher mucosal uptake, probably because oxidation of Fe(II) in the alkaline milieu of the intestine, which leads to formation of non-absorbable Fe(III) complexes, was prevented. The mucosal transfer fraction of both compounds was identical.