Khatib, Moustafa M. El

706 Background: In recent years, there has been a shift towards neo-adjuvant treatment (NAT) of non-metastatic pancreas cancer in the hopes of improving negative margin rate, lymph node negativity, recurrence and survival. Even patients deemed resectable based on NCCN criteria are receiving NAT but data for these patients remains limited. This current study evaluated the outcomes of patients diagnosed with resectable pancreatic adenocarcinoma. Methods: Patients were retrospectively identified through the Mayo Clinic, Rochester SPORE pancreatic cancer registry as well as search of the electronic medical record via Advanced Cohort Explorer from May 2011 to 2016. Baseline demographics, tumor characteristics, treatments rendered, and outcomes were collected. Variables were analyzed for association with recurrence from time of surgery and survival from time of diagnosis using Kaplan-Meier curves and Cox proportional hazards regression. Results: A total of 520 patients with resectable pancreatic adenocarcinoma were identified. 72 patients received upfront chemotherapy with 44 (61.1%) proceeding to surgical resection. 62 patients received upfront chemotherapy followed by radiation with 33 (53.2%) proceeding to surgical resection. 12 patients received upfront radiation alone with 7 (58.3%) proceeding to surgical resection. 374 patients did not receive any NAT with 293 (78.3%) proceeding to surgical resection. In total, 377 (72.5%) went to resection. Median time to recurrence from surgery was 27.7 months vs. 21.7 months for NAT and upfront resection, respectively (HR 0.87, 95% CI 0.60-1.72, p = 0.48). Median overall survival from diagnosis for those receiving NAT was 40.6 months vs. 24.7 months for those receiving upfront resection (HR 0.62, 95% CI 0.41-0.92, p = 0.02). Conclusions: This study shows an approximate 16 month improvement in overall survival of patients receiving upfront NAT for resectable pancreatic adenocarcinoma. This might be due to a better selection of patients. It also highlights that not all patients with resectable cancer undergo resection. Further studies are warranted to identify why resectable patients are not proceeding to resection and which specific NAT approaches benefit patients the most.

Abstract Human induced pluripotent stem cells (iPSCs) and derived progeny provide invaluable regenerative platforms, yet their clinical translation has been compromised by their biosafety concern. Here, we assessed the safety of transplanting patient-derived iPSC-generated pancreatic endoderm/progenitor cells. Transplantation of progenitors from iPSCs reprogrammed by lentiviral vectors (LV-iPSCs) led to the formation of invasive teratocarcinoma-like tumors in more than 90% of immunodeficient mice. Moreover, removal of primary tumors from LV-iPSC progeny-transplanted hosts generated secondary and metastatic tumors. Combined transgene-free (TGF) reprogramming and elimination of residual pluripotent cells by enzymatic dissociation ensured tumor-free transplantation, ultimately enabling regeneration of type 1 diabetes-specific human islet structures in vivo. The incidence of tumor formation in TGF-iPSCs was titratable, depending on the oncogenic load, with reintegration of the cMYC expressing vector abolishing tumor-free transplantation. Thus, transgene-free cMYC-independent reprogramming and elimination of residual pluripotent cells are mandatory steps in achieving transplantation of iPSC progeny for customized and safe islet regeneration in vivo. Significance Pluripotent stem cell therapy for diabetes relies on the safety as well as the quality of derived insulin-producing cells. Data from this study highlight prominent tumorigenic risks of induced pluripotent stem cell (iPSC) products, especially when reprogrammed with integrating vectors. Two major underlying mechanisms in iPSC tumorigenicity are residual pluripotent cells and cMYC overload by vector integration. This study also demonstrated that combined transgene-free reprogramming and enzymatic dissociation allows teratoma-free transplantation of iPSC progeny in the mouse model in testing the tumorigenicity of iPSC products. Further safety assessment and improvement in iPSC specification into a mature β cell phenotype would lead to safe islet replacement therapy for diabetes.

Surgical trainees undergo demanding training to achieve high surgical task proficiency. Abounding clinical and educational responsibilities mandate efficient and effective training. This research measured resident workload during laparoscopic skills training to identify excessive workload and how workload impacted task performance. Twenty-eight surgical trainees performed a standardized surgical training task and completed a workload questionnaire while observers measured physiological stress, posture risk assessment, and task performance. Participants self-reported mental demands, physical demands, temporal demands, performance, effort, and frustration. Effort (12±4) and frustration (12±5) were the highest subscales while physical demand (8±4) was the lowest. All participants were observed performing the task in at-risk postures, with 21% exhibiting risk levels requiring immediate intervention. Physical demand was associated with posture risk assessment scores (p<0.05). Mental demand was positively (R 2 =0.20, p<0.05) and frustration was negatively (R 2 =0.18, p<0.05) associated with skin conductance range. A point increase in physical demand was associated with a six second increase in performance time (β=6.0, p=0.01). These results support the fact that human factors and ergonomic tools can be used to relate surgical skills performance with workload, stress, and posture risks.