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Background:Outcomes after open esophagectomy (OE) have been shown to depend on institution case volume. We aim to determine whether a similar relationship exists for minimallyinvasive esophagogastrectomy (MIE). Methods: Patients who had OE or MIE (excluding robotic procdures) between 2010 and 2013 in the National Cancer Database were included. Outcomes included 30-and 90-day mortality, length-of-stay, hospital readmission, margin positivity, and number of lymph nodes harvested. Logistic and linear regression were used to adjust for possible confounders including age, gender, tumor size, Charlson score, induction therapy, and type of institution (academic vs. community-based). Results:We identified 2371 patients in the MIE group and 6285 patients in the OE group. In multivariate analysis, high case volume was an independent predictor for lower 30-day, 90-day mortality, shorter length-of-stay, and higher rate of negative-margin resection in OE (P<0.001) but not MIE. After quartile ranking of institutions based on volume, MIE outcomes were found to be better in institutions in the highest volume quartile compared to those in the lowest (p< 0.0001). Conclusions:In this dataset, MIE postoperative outcomes, unlike OE, did not correlate with hospital case volume. Volume-outcome relationships may be affected by surgical approach.The effect of case volume on long-term outcomes after MIE warrants further study.

Multimodality neoadjuvant therapy may lead to complete pathologic response in a small number of patients with borderline resectable/locally advanced pancreatic adenocarcinoma. pCR to neoadjuvant therapy does not lead to cure in most cases, and the majority of patients appear to relapse locally or systemically.

The differentiated state of spinal cord ependymal cells in regeneration-competent amphibians varies between a constitutively active state in what is essentially a developing organism, the tadpole of the frog Xenopus laevis, and a quiescent, activatable state in a slowly growing adult salamander Ambystoma mexicanum, the Axolotl. Ependymal cells are epithelial in intact spinal cord of all vertebrates. After transection, body region ependymal epithelium in both Xenopus and the Axolotl disorganizes for regenerative outgrowth (gap replacement). Injury-reactive ependymal cells serve as a stem/progenitor cell population in regeneration and reconstruct the central canal. Expression patterns of mRNA and protein for the stem/progenitor cell-maintenance Notch signaling pathway mRNA-binding protein Musashi (msi) change with life stage and regeneration competence. Msi-1 is missing (immunohistochemistry), or at very low levels (polymerase chain reaction, PCR), in both intact regeneration-competent adult Axolotl cord and intact non-regeneration-competent Xenopus tadpole (Nieuwkoop and Faber stage 62+, NF 62+). The critical correlation for successful regeneration is msi-1 expression/upregulation after injury in the ependymal outgrowth and stump-region ependymal cells. msi-1 and msi-2 isoforms were cloned for the Axolotl as well as previously unknown isoforms of Xenopus msi-2. Intact Xenopus spinal cord ependymal cells show a loss of msi-1 expression between regeneration-competent (NF 50–53) and non-regenerating stages (NF 62+) and in post-metamorphosis froglets, while msi-2 displays a lower molecular weight isoform in non-regenerating cord. In the Axolotl, embryos and juveniles maintain Msi-1 expression in the intact cord. In the adult Axolotl, Msi-1 is absent, but upregulates after injury. Msi-2 levels are more variable among Axolotl life stages: rising between late tailbud embryos and juveniles and decreasing in adult cord. Cultures of regeneration-competent Xenopus tadpole cord and injury-responsive adult Axolotl cord ependymal cells showed an identical growth factor response. Epidermal growth factor (EGF) maintains mesenchymal outgrowth in vitro, the cells are proliferative and maintain msi-1 expression. Non-regeneration competent Xenopus ependymal cells, NF 62+, failed to attach or grow well in EGF+ medium. Ependymal Msi-1 expression in vivo and in vitro is a strong indicator of regeneration competence in the amphibian spinal cord.