Establishment of pathological quantitative method for determining undifferentiated component ratio in patients with differentiated/undifferentiated mixed-type early gastric cancer and clinical significance of this ratio.

PURPOSES: The purpose of this study was to establish a pathological quantitative method for determining the undifferentiated components ratio (UCR) in patients with differentiated/undifferentiated mixed-type (Mixed-type) early gastric cancer (EGC) and to examine the clinical significance. METHODS: The subjects were 410 patients who underwent surgical resection for EGC with the invasion limited to m or sm1. Analysis 1: In 12 randomly selected patients with Mixed-type cancer, we calculated the area ratio and the ratio of the length ratio using ImageJ and analyzed the correlation between them. Analysis 2: We generated ROC curves, and determined the cutoff UCR on the basis of the predictive risk factors for lymph node metastasis (LNM). Analysis 3: We analyzed the relationship between clinicopathological factors including UCR/length of undifferentiated component (LUC = maximum dimensions of tumor × UCR) and LNM. RESULTS: Analysis 1: The length ratio can be used as a substitute parameter for the UCR (r = 0.996). Analysis 2: The cutoff UCR as a risk factor for LNM was 58% (sensitivity = 1, 1 - specificity = 0.404). Analysis 3: Lymphovascular invasion (p < 0.0001), UCR ≥58% (p = 0.023), and LUC ≥25 mm (p = 0.005) were identified as significant risk factors for LNM. No LNM was observed in patients with invasion limited to m or sm1 and negativity for lymphovascular invasion and UCR <58% (0/215). CONCLUSIONS: In the patients with Mixed-type EGC, the length ratio of undifferentiated components can be a substitute parameter for the UCR. LNM rarely occurs in patients without lymphovascular invasion and with an UCR <58%. The analysis of the UCR has great significance in determining whether additional surgical resection is required after endoscopic resection.

Endoscopic self-expandable metal stent placement for malignant afferent loop obstruction caused by peritoneal recurrence after total gastrectomy.

Afferent loop obstruction (ALO) caused by cancer recurrence after total gastrectomy (TG) can be managed by either surgical or non-surgical treatment. The general condition of patients with recurrent gastric cancer is often poor, so a less invasive non-surgical treatment is desirable. We report the case of a 75-year-old male who had undergone TG for gastric cancer 6 months previously and who presented at our hospital with abdominal pain and vomiting. Abdominal computed tomography scan showed a dilated afferent loop, and additionally a low-density lesion around jejunojejunal anastomosis, suggesting that ALO is associated with peritoneal recurrence. A self-expandable metal stent (SEMS) was endoscopically placed to treat ALO after decompression of the dilated afferent loop using an intestinal tube. He retained a good quality of life until his death due to cancer progression 5 months after the SEMS placement. Our case indicates that SEMS could be a less invasive alternative to surgery, and may confer a better quality of life for patients with ALO due to cancer recurrence after TG. This is the valuable report of case in which endoscopic metallic stent placement succeeded for ALO caused by peritoneal recurrence after TG.

Recent developments in gastric endoscopic submucosal dissection: towards the era of endoscopic resection of layers deeper than the submucosa.

With technical advances in endoscopic submucosal dissection (ESD), several variations of endoscopic procedure derived from ESD and fusion procedures of endoscopy and laparoscopy for upper gastrointestinal submucosal tumor and cancer have recently been developed. The former includes endoscopic muscularis dissection (EMD), submucosal endoscopic tumor resection (SET), endoscopic submucosal tunnel dissection (ESTD) and endoscopic full-thickness resection (EFTR), and the latter includes laparoscopic and endoscopic cooperative surgery (LECS), laparoscopy-assisted endoscopic full-thickness resection (LAEFR), and laparoscopic lymphadenectomy without gastrectomy following ESD. In the present article, recent developments in gastric ESD and advanced procedures derived from ESD are discussed.