Our results indicate that DTR is a useful reconstruction method after PG, especially in terms of preventing reflux esophagitis and anastomotic strictures.

LG can be a feasible treatment that is beneficial in terms of earlier recovery after operation and can be expected to result in similar survival as OG in patients with AGC.

BackgroundMechanistic target of rapamycin (mTOR) pathway is essential for the growth of gastric cancer (GC), but mTOR inhibitor everolimus was not effective for the treatment of GCs. The Cancer Genome Atlas (TCGA) researchers reported that most diffuse-type GCs were genomically stable (GS). Pathological analysis suggested that some diffuse-type GCs developed from intestinal-type GCs.MethodsWe established patient-derived xenograft (PDX) lines from diffuse-type GCs, and searched for drugs that suppressed their growth. Diffuse-type GCs were classified into subtypes by their gene expression profiles.ResultsmTOR inhibitor temsirolimus strongly suppressed the growth of PDX-derived diffuse-type GC-initiating cells, which was regulated via Wnt-mTOR axis. These cells were microsatellite unstable (MSI) or chromosomally unstable (CIN), inconsistent with TCGA report. Diffuse-type GCs in TCGA cohort could be classified into two clusters, and GS subtype was major in cluster I while CIN and MSI subtypes were predominant in cluster II where PDX-derived diffuse-type GC cells were included. We estimated that about 9 and 55% of the diffuse-type GCs in cluster II were responders to mTOR inhibitors and checkpoint inhibitors, respectively, by identifying PIK3CA mutations and MSI condition in TCGA cohort. These ratios were far greater than those of diffuse-type GCs in cluster I or intestinal-type GCs. Further analysis suggested that diffuse-type GCs in cluster II developed from intestinal-type GCs while those in cluster I from normal gastric epithelial cells.ConclusionmTOR inhibitors and checkpoint inhibitors might be useful for the treatment of a subset of diffuse-type GCs which may develop from intestinal-type GCs.Electronic supplementary materialThe online version of this article (10.1186/s13046-019-1121-3) contains supplementary material, which is available to authorized users.

Roux-en-Y reconstruction was superior to Billroth I reconstruction in terms of frequency of occurrence of residual food, bile reflux, remnant gastritis, and reflux esophagitis in the long term. Differences between the two methods became more evident as the follow-up period lengthened.

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