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Objective: With advancements in surgical equipment and procedures, human–system interactions in operating rooms affect surgeon workload and performance. Workload was measured across surgical specialties using surveys to identify potential predictors of high workload for future performance improvement. Summary Background Data: Surgical instrumentation and technique advancements have implications for surgeon workload and human–systems interactions. To understand and improve the interaction of components in the work system, NASA-Task Load Index can measure workload across various fields. Baseline workload measurements provide a broad overview of the field and identify areas most in need of improvement. Methods: Surgeons were administered a modified NASA-Task Load Index survey (0 = low, 20 = high) following each procedure. Patient and procedural factors were retrieved retrospectively. Results: Thirty-four surgeons (41% female) completed 662 surgery surveys (M = 14.85, SD = 7.94), of which 506 (76%) have associated patient and procedural data. Mental demand (M = 7.7, SD = 5.56), physical demand (M = 7.0, SD = 5.66), and effort (M = 7.8, SD = 5.77) were the highest rated workload subscales. Surgeons reported difficulty levels higher than expected for 22% of procedures, during which workload was significantly higher ( P < 0.05) and procedural durations were significantly longer ( P > 0.001). Surgeons reported poorer perceived performance during cases with unexpectedly high difficulty ( P < 0.001). Conclusions: When procedural difficulty is greater than expected, there are negative implications for mental and physical demand that result in poorer perceived performance. Investigations are underway to identify patient and surgical variables associated with unexpected difficulty and high workload. Future efforts will focus on re-engineering the surgical planning process and procedural environment to optimize workload and performance for improved surgical care.

e15703 Background: The aim of this study is to identify prognostic factors and effects of adjuvant therapy for patients with ampullary adenocarcinoma who had pancreatoduodenectomy. Methods: A cohort of 123 consecutive patients underwent pancreatoduodenectomy for ampullary adenocarcinoma from January 1, 2006, through August 31, 2016 at Mayo Clinic in Rochester, MN. Only patients with ampullary carcinoma by pathology review were included and were histologically classified as pancreaticobiliary or intestinal subtypes. Median follow-up duration was 41.0 months. Patient survival and its correlation with patient and tumor variables were tested by univariate and multivariate analysis. Results: Pancreatoduodenectomy was curative-intent in 120 out of 123 patients. All 123 patients underwent radical surgery, 32 patients (26.0%) had laparoscopic pancreatoduodenectomy. Among 123 patients, there were 76 men (61.8%).Median age at diagnosis was 67.2 years. 54 patients (45%) without metastatic disease upon surgery had adjuvant therapy (35 patients had chemotherapy only while 19 patient also had radiation). Median overall survival (OS) was 91.8 months. Poor performance status at disease diagnosis (ECOG > = 1), old age ( > = 70 years), primary tumor infiltration (T), lymph node metastasis (N), and advanced disease stage (TNM) had a significant negative impact on survival (p < 0.05 by univariate analysis). Gender, diabetes at disease diagnosis, laparoscopic surgery approach, number of lymph nodes removed, number of positive lymph nodes, and tumor size did not influence survival. In multivariate analysis, ECOG score > = 1, adjuvant treatment, primary tumor infiltration (T) and lymph node metastasis (N) remained statistically significant. Adjuvant therapy was independently associated with improved disease free survival (P = 0.0388) and overall survival (p = 0.030) for patients with advanced disease (stage IIB and above). Conclusions: Poor performance status and advanced disease stage are associated with decreased survival in patients with ampullary adenocarcinoma. Patients with advanced disease should be considered for adjuvant chemotherapy.

e15045 Background: BRAF V600E mutations are present in 7% of mCRC patients (pts) and portend a poor prognosis. Data guiding initial treatment decisions are limited. This study investigates the management approach and clinical impact of utilizing metastasectomy for pts with BRAF V600E mCRC. Methods: By using prospective clinical and molecular data from Mayo Clinic, pts with BRAF V600E mCRC were analyzed for clinical characteristics, treatment and survival outcomes. Statistical analyses utilized Kaplan-Meier method, Log-rank test, and Cox proportional hazards models. Results: 164 pts with BRAF V600E mCRC were identified between 6/1999-8/2015. Complete follow up data were available for 52 pts. Median age of 65 years, 61% female, ECOG PS ≤ 1, 71% of pts had right sided tumors and 28% presented with liver limited metastasis. Only 7% (4/52) received FOLFOXIRI/BEV (average of 8 cycles). Peripheral neuropathy, pending BRAF status , and prior progression on FOLFOX, were the most common reasons documented for avoiding FOLFOXIRI/BEV. FOLFOX/BEV was the most common 1st line regimen used (32% of pts). Median overall survival (mOS) for all 52 pts was 25 months (mo) with median progression free survival (PFS) of 9.3 mo, reflecting worse survival when compared to BRAF wild-type control patients treated at Mayo Clinic (249 pts, mOS: 43 mo). With median follow up of 18.3 mo, 21 pts who underwent metastasectomy had improved OS (29.1mo vs. 22.7mo, HR = 0.33; CI: 0.12-0.78; p = 0.01) and PFS (13.6mo vs. 6.2mo, HR = 0.53, CI: 0.28-0.97; p = 0.03) when compared to the non-metastasectomy cohort, respectively. In multivariate analysis, metastasectomy remained statistically significant for improved survival outcomes (HR 0.52; 95% CI 0.07-1.02; p = 0.02). Median relapse-free survival after metastasectomy was 9.7 mo (95% CI, 5.5 mo-19.5 mo). Only 2 pts remain disease free at the time of last follow up, with 1 pt without recurrent disease for greater than 2 years (28.9 mo). Conclusions: The use of multimodality therapy incorporating metastasectomy for BRAF V600E mCRC is a critical component for enhanced survival outcomes.

Abstract The Hippo pathway effector, Yes-associated protein (YAP), is a transcriptional coactivator implicated in cholangiocarcinoma (CCA) pathogenesis. YAP is known to be regulated by a serine/threonine kinase relay module (MST1/2–LATS1/2) culminating in phosphorylation of YAP at Serine 127 and cytoplasmic sequestration. However, YAP also undergoes tyrosine phosphorylation, and the role of tyrosine phosphorylation in YAP regulation remains unclear. Herein, YAP regulation by tyrosine phosphorylation was examined in human and mouse CCA cells, as well as patient-derived xenograft (PDX) models. YAP was phosphorylated on tyrosine 357 (Y357) in CCA cell lines and PDX models. SRC family kinase (SFK) inhibition with dasatinib resulted in loss of YAPY357 phosphorylation, promoted its translocation from the nucleus to the cytoplasm, and reduced YAP target gene expression, including cell lines expressing a LATS1/2-resistant YAP mutant in which all serine residues were mutated to alanine. Consistent with these observations, precluding YAPY357 phosphorylation by site-directed mutagenesis (YAPY357F) excluded YAP from the nucleus. Targeted siRNA experiments identified LCK as the SFK that most potently mediated YAPY357 phosphorylation. Likewise, inducible CRISPR/Cas9-targeted LCK deletion decreased YAPY357 phosphorylation and its nuclear localization. The importance of LCK in CCA biology was demonstrated by clinical observations suggesting LCK expression levels were associated with early tumor recurrence following resection of CCA. Finally, dasatinib displayed therapeutic efficacy in PDX models. Mol Cancer Res; 16(10); 1556–67. ©2018 AACR.

Purpose Data that guide selection of optimal local ablative therapy for the management localized hepatocellular carcinoma (HCC) are lacking. Because there are limited prospective comparative data for these treatment modalities, we aimed to compare the effectiveness of radiofrequency ablation (RFA) versus stereotactic body radiotherapy (SBRT) by using the National Cancer Database. Methods We conducted an observational study to compare the effectiveness of RFA versus SBRT in nonsurgically managed patients with stage I or II HCC. Overall survival was compared by using propensity score–weighted and propensity score–matched analyses based on patient-, facility-, and tumor-level characteristics. A sensitivity analysis was performed to evaluate the effect of severe fibrosis/cirrhosis. In addition, we performed exploratory analyses to determine the effectiveness of RFA and SBRT in clinically relevant patient subsets. Results Overall, 3,684 (92.6%) and 296 (7.4%) nonsurgically managed patients with stage I or II HCC received RFA or SBRT, respectively. After propensity matching, 5-year overall survival was 29.8% (95% CI, 24.5% to 35.3%) in the RFA group versus 19.3% (95% CI, 13.5% to 25.9%) in the SBRT group ( P < .001). Inverse probability–weighted analysis yielded similar results. The benefit of RFA was consistent across all subgroups examined and was robust to the effects of severe fibrosis/cirrhosis. Conclusion Our study suggests that treatment with RFA yields superior survival compared with SBRT for nonsurgically managed patients with stage I or II HCC. Even though our results are limited by the biases related to the retrospective study design, we believe that, in the absence of a randomized clinical trial, our findings should be considered when recommending local ablative therapy for localized unresectable HCC.

Abstract Background BRAF V600E mutations are present in 8%–10% of patients with metastatic colorectal cancer (mCRC) and portend poor prognosis. This study investigated the impact of metastasectomy for patients with BRAF V600E mCRC. Subjects, Materials, and Methods Using prospective clinical and molecular data, patients with BRAF V600E mCRC were analyzed for clinical characteristics and survival. Statistical analyses utilized the Kaplan-Meier method, log-rank test, and Cox proportional hazard models. Results Fifty-two patients were identified between July 1, 2008, and January 4, 2016. Patient characteristics included median age 65 years, 61% female, Eastern Cooperative Oncology Group performance status ≤1, 71% with right-sided tumors, and 28% with liver-limited metastasis. In the first-line setting, 7% (4/52) received fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI)/bevacizumab (BEV) and 81% were treated with doublet chemotherapy consisting of fluoropyrimidine, oxaliplatin, and BEV. Median overall survival (OS) for all 52 patients was 25 months with median progression-free survival (PFS) of 9.3 months. With median follow-up of 18.3 months, 21 patients underwent metastasectomy with longer OS (29.1 months vs. 22.7 months, hazard ratio [HR] = 0.33; confidence interval [CI], 0.12–0.78; p = .01) and PFS (13.6 months vs. 6.2 months, HR = 0.53, CI, 0.28–0.97; p = .03) compared with the non-metastasectomy cohort. In multivariate analysis, metastasectomy remained significant for improved survival outcomes (HR = 0.52; 95% CI, 0.07–1.02; p = .02). Median disease-free survival after metastasectomy was 9.7 months (95% CI, 5.5–19.5). Two patients remain disease-free at the time of last follow-up, with one patient without relapse for greater than 2 years (28.9 months). Conclusion Multimodality therapy incorporating metastasectomy for BRAF V600E mCRC should be considered and might be associated with improved overall survival in select patients. Implications for Practice BRAF V600E metastatic colorectal cancer (mCRC) represents an extremely difficult molecular subset of colorectal cancer to treat. To date, this subset remains refractory to standard chemotherapies, prompting extensive clinical investigation regarding novel treatment approaches and targeted modalities. While the use of metastasectomy for expanded RAS wild-type and RAS mutated mCRC has resulted in improved overall survival for select patients, utilization of metastasectomy in patients with BRAF V600E mCRC remains controversial. This article explores the authors' experience with BRAF V600E mCRC to ascertain whether a multidisciplinary approach incorporating metastasectomy for well-selected patients improves overall survival.

Abstract Background: The paucity of effective therapeutic agents for hepatocellular cancer (HCC) underscores the critical need for more effective therapeutic strategies. Recent studies indicate lipid biosynthesis and desaturation is required for HCC survival. Targeting these may prove beneficial because such changes contribute to therapeutic resistance. Stearoyl CoA desaturase (SCD1), a key mediator of fatty acid (FA) biosynthesis and rate-limiting in conversion of saturated fatty acids (SFAs) to mono-unsaturated fatty acids (MUFAs), is upregulated in HCC and many other cancers. As such, we therapeutically targeted a novel lipogenic tumor survival mechanism mediated by SCD1 as a means to combat the chemoresistance associated with HCC. In so doing, we evaluated a novel lead SCD1 inhibitor in HCC. Methods: Paraffin embedded patient HCC tissues were examined for SCD1 expression. Using combined computational and synthetic chemistry approaches, we synthesized four novel specific SCD1 inhibitors with SSI-4 being the lead SCD1 inhibitor. HCC cell lines were examined using proliferation assays for response to SSI-4. IC50 concentrations for blocking SCD1 enzyme activity was determined. Blood half-life and bioavailability of single dose SSI-4 was determined. Mechanisms of action of SCD1 were examined that included Endoplasmic reticulum (ER) stress. In vivo, antitumor activity was determined using HCC patient derived xenograft (PDX) mouse models. Results: We identified elevated SCD1 mRNA and protein in HCCs tissues. SSI-4 dose-dependently inhibits cell proliferation in HCC cell lines with specificity demonstrated by oleic acid (MUFA) co-culture. Single dose oral gavage SSI-4 demonstrated a half-life of ~4 hours and excellent oral bioavailability. SSI-4 was well tolerated with long-term daily dosing. SSI-4 treatment of HCC cells and tumors led to endoplasmic reticulum (ER) stress followed by apoptotic cell death. Single agent SSI-4 demonstrated antitumor activity in HCC PDX mouse models with suppression of ER stress regulated proteins. Conclusions: Targeting a novel lipid metabolic pathway in HCC may provide effective therapy for aggressive HCC. Citation Format: John Alton Copland, Laura A. Marlow, Ilah Bok, James L. Miller, Matsuda Akiko, Yan W. Asmann, Vivekananda Sarangi, Steven R. Alberts, Kabir Mody, Lewis R. Roberts, Mark J. Truty, Tushar C. Patel. Targeting stearoyl CoA desaturase 1 (SCD1) in hepatobilliary carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 192. doi:10.1158/1538-7445.AM2017-192

AbstractThe Hippo pathway effector YAP is implicated in the pathogenesis of cholangiocarcinoma (CCA). The Hippo pathway relies on signaling cross talk for its regulation. Given the importance of platelet derived growth factor receptor (PDGFR) signaling in CCA biology, our aim was to examine potential YAP regulation by PDGFR. We employed human and mouse CCA specimens and cell lines for these studies. Initially, we confirmed upregulation of PDGFRβ and PDGFR ligands in human and mouse CCA specimens and cell lines. YAP, a transcriptional co‐activator, was localized to the nucleus in human CCA specimens and a cell line, as well as patient derived xenografts (PDX). PDGFR pharmacologic inhibition led to a redistribution of YAP from the nucleus to cytosol and downregulation of YAP target genes in a human CCA cell line. siRNA silencing of PDGFR‐β similarly downregulated YAP target genes. YAP activation (nuclear localization and target gene expression) was regulated by Src family kinases (SFKs) downstream of PDGFR. SFK activity resulted in phosphorylation of YAP on tyrosine357 (YAPY357). The importance of YAPY357 phosphorylation in regulating YAP activation was confirmed utilizing the SB‐1 cell line, a mouse cell line expressing YAP S127A precluding canonical serine phosphorylation. PDGFR inhibition decreased cellular abundance of the survival protein Mcl‐1, a known YAP target gene, and accordingly increased cell death in CCA cells in vitro and in vivo. These preclinical data demonstrate that a PDGFR‐SFK cascade regulates YAP activation via tyrosine phosphorylation in CCA. Inhibiting this cascade may provide a viable therapeutic strategy for this human malignancy.