Citations

AbstractBackgroundThe accuracy of the eighth AJCC ypTNM staging system on the prognosis of gastric cancer (GC) patients after neoadjuvant therapy (NAT) is controversial. This study aimed to develop and validate a novel staging system using the log odds of positive lymph nodes scheme (LODDS).MethodsA retrospective analysis of 606 GC patients who underwent radical gastrectomy after neoadjuvant therapy was conducted as the development cohort. (Fujian Medical University Affiliated Union Hospital (n = 183), Qinghai University Affiliated Hospital (n = 169), Mayo Clinic (n = 236), Lanzhou University First Hospital (n = 18)). The validation cohort came from the SEER database (n = 1701). A novel ypTLoddsS (ypTLM) staging system was established using the 3‐year overall survival. The predictive performance of two systems was compared. ResultsTwo‐step multivariate Cox regression analysis in both cohorts showed that ypTLM was an independent predictor of overall survival of GC patients after neoadjuvant therapy (HR: 1.57, 95% CI: 1.30–1.88, p < 0.001). In the development cohort, ypTLM had better discrimination ability than ypTNM (C‐index: 0.663 vs 0.633, p < 0.001), better prediction homogeneity (LR: 97.7 vs. 70.9), and better prediction accuracy (BIC: 3067.01 vs 3093.82; NRI: 0.36). In the validation cohort, ypTLM had a better prognostic predictive ability (C‐index: 0.614 vs 0.588, p < 0.001; LR: 11,909.05 vs. 11,975.75; BIC: 13,263.71 vs 13,328.24; NRI: 0.22). The time‐dependent ROC curve shows that the predictive performance of ypTLM is better than ypTNM, and the analysis of the decision curve shows that ypTLM achieved better net benefits. ConclusionA LODDS‐based ypTLM staging system based on multicenter data was established and validated. The predictive performance was superior to the eighth AJCC ypTNM staging system.

BACKGROUND: Accurate staging prior to resection of pancreatic ductal adenocarcinoma (PDAC) is imperative to avoid unnecessary operative morbidity and oncologic futility in patients with occult intra-abdominal distant metastases. We aimed to determine the diagnostic yield of staging laparoscopy (SL) and to identify factors associated with increased risk of positive laparoscopy (PL) in the modern era. STUDY DESIGN: Patients with radiographically localized PDAC who underwent SL from 2017 to 2021 were retrospectively reviewed. The yield of SL was defined as the proportion of patients with PL, including gross metastases and/or positive peritoneal cytology. Factors associated with PL were assessed using univariate analysis and multivariable logistic regression. RESULTS: Of 1,004 patients who underwent SL, 180 (18%) had PL due to gross metastases (n = 140) and/or positive cytology (n = 96). Patients who had neoadjuvant chemotherapy prior to laparoscopy had lower rates of PL (14% vs 22%, p = 0.002). When the analysis was restricted to chemo-naive patients who had concurrent peritoneal lavage performed, 95 of 419 patients (23%) had PL. In multivariable analysis, PL was associated with younger (<60) age, indeterminate extrapancreatic lesions on preoperative imaging, body/tail tumor location, larger tumor size, and elevated serum CA 19-9 (all p < 0.05). Among patients with no indeterminate extrapancreatic lesions on preoperative imaging, the rate of PL ranged from 1.6% in patients with no risk factors to 42% in young patients with large body/tail tumors and elevated serum CA 19-9. CONCLUSIONS: The rate of PL in patients with PDAC remains high in the modern era. SL with peritoneal lavage should be considered for the majority of patients prior to resection, specifically those with high-risk features, and ideally prior to neoadjuvant chemotherapy.

Abstract Introduction: Cholangiocarcinoma (CCA) is a highly lethal, and biologically heterogenous malignancy arising from the biliary tree. With only moderate responses to cytotoxic chemotherapy and despite the development of targeted therapies, treatment success has been hindered by primary or acquired resistance. New therapeutic strategies are necessary to improve outcomes in these patients. NXP800 is a heat shock factor 1 (HSF1) small-molecule inhibitor with activity previously noted in ovarian cancers with ARID1A mutations. ARID1A mutations are common, well-known players in cholangiocarcinoma. In preclinical exploratory studies, we examined treatment responses in validated cholangiocarcinoma patient derived xenograft (PDX) models. Methods: In our preliminary studies we evaluated response to HSF1 inhibition in a single, ARID1A wildtype PDX model. Xenografts were expanded into the flank of NOD/SCID mice and treatment begun when tumors averaged 120mm3. 16 tumor bearing mice were randomized and 8 mice were grouped into both the treatment and control arms. Mice were then treated with either NXP800 (35 mg/kg), in the treatment arm, or vehicle, in the control arm, via oral gavage 5 days on, 2 days off, for 28 days. Tumor volume and animal weight were collected twice weekly. Results: After screening of our Human CCA PDX library of 57 patients, we identified an established and histologically validated PDX from a patient with intrahepatic cholangiocarcinoma obtained at surgical resection. Molecular characterization of the tumor identified NRAS Q61 mutation, FGFR1 and FGFR2 overexpression, androgen receptor overexpression, microsatellite stability, and a total tumor mutational burden of 2.6. RNA sequencing was completed and an evaluation of a 21-gene signature of YAP activity had identified this PDX as having an elevated activity signature compared to a cohort of 27 additional PDX tumors. Treatment with NXP800 was associated with a statistically significant decrease in tumor size compared to control tumor bearing mice, with a mean difference of the delta in tumor volume (852.6 mm3; 95% CI: 321 - 1384; P-value = 0.0057). Conclusion: NXP800, a HSF1 inhibitor, demonstrated significant therapeutic activity in a cholangiocarcinoma PDX. Further studies are needed and being performed to determine the role of HSF1 inhibition in human cholangiocarcinoma. Citation Format: Danielle M. Carlson, Amro Abdelrahman, Alessandro Fogliati, Isaac Lynch, Jennifer Tomlinson, Mark Truty, Rory Smoot. Inhibition of HSF1 demonstrates therapeutic efficacy in preclinical models of cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2237.

Objective Pancreatic ductal adenocarcinoma (PDAC) displays a remarkable propensity towards therapy resistance. However, molecular epigenetic and transcriptional mechanisms enabling this are poorly understood. In this study, we aimed to identify novel mechanistic approaches to overcome or prevent resistance in PDAC. Design We used in vitro and in vivo models of resistant PDAC and integrated epigenomic, transcriptomic, nascent RNA and chromatin topology data. We identified a JunD-driven subgroup of enhancers, called interactive hubs (iHUBs), which mediate transcriptional reprogramming and chemoresistance in PDAC. Results iHUBs display characteristics typical for active enhancers (H3K27ac enrichment) in both therapy sensitive and resistant states but exhibit increased interactions and production of enhancer RNA (eRNA) in the resistant state. Notably, deletion of individual iHUBs was sufficient to decrease transcription of target genes and sensitise resistant cells to chemotherapy. Overlapping motif analysis and transcriptional profiling identified the activator protein 1 (AP1) transcription factor JunD as a master transcription factor of these enhancers. JunD depletion decreased iHUB interaction frequency and transcription of target genes. Moreover, targeting either eRNA production or signaling pathways upstream of iHUB activation using clinically tested small molecule inhibitors decreased eRNA production and interaction frequency, and restored chemotherapy responsiveness in vitro and in vivo. Representative iHUB target genes were found to be more expressed in patients with poor response to chemotherapy compared with responsive patients. Conclusion Our findings identify an important role for a subgroup of highly connected enhancers (iHUBs) in regulating chemotherapy response and demonstrate targetability in sensitisation to chemotherapy.

Mixed acinar neuroendocrine carcinoma of the pancreas (MANEC-P) is an extremely rare malignancy with a poor prognosis. However, epidemiological estimates of MANEC-P remain unknown. This study aimed to estimate and compare the incidence, prevalence, and cancer-specific survival (CSS) of MANEC-P in the United States (US). Patients with MANEC-P were identified through the Surveillance, Epidemiology, and End Results (SEER) and National Program of Cancer Registries databases between 2000–2017. The primary outcomes included age-adjusted incidence rate, limited-duration prevalence, and CSS. A total of 630 patients were identified for the incidence analysis and 149 for the prevalence and CSS analyses. The MANEC-P incidence rate was 0.011 per 100,000 individuals, which was the lowest among pancreatic cancer histologic subtypes. The incidence rate was significantly higher in men and Black races and peaked at 75–79 years of age. The incidence rate was the lowest in the midwestern region (0.009) and the highest in the northeastern US (0.013). The 17-year prevalence was 0.00005%, indicating that 189 patients were alive in the United States at the beginning of 2018. The median CSS of MANEC-P was estimated to be 41 (23, 69) months. In conclusion, MANEC-P is very rare, and its incidence rate has been steady in the US over the last two decades. MANEC-P has a poor prognosis and is the 5th leading cause of pancreatic cancer-related death in the US.

Abstract Background and study aims Gastric outlet obstruction (GOO) is traditionally managed with surgical gastroenterostomy (surgical-GE) and enteral stenting (ES). Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is now a third option. Large studies assessing their relative risks and benefits with adequate follow-up are lacking. We conducted a comparative analysis of patients who underwent EUS-GE, ES, or surgical-GE for GOO. Patients and methods In this retrospective comparative cohort study, consecutive patients presenting with GOO who underwent EUS-GE, ES, or surgical-GE at two academic institutions were reviewed and independently cross-edited to ensure accurate reporting. The primary outcome was need for reintervention. Secondary outcomes were technical and clinical success, length of hospital stay (LOS), and adverse events (AEs). Results A total of 436 patients (232 EUS-GE, 131 ES, 73 surgical-GE) were included. The median duration of follow-up of the entire cohort was 185.5 days (interquartile range 55.25–454.25 days). The rate of reintervention in the EUS-GE group was lower than in the ES and surgical-GE groups (0.9 %, 12.2 %, and 13.7 %, P < 0.0001). Technical success was achieved in 98.3 %, 99.2 %, and 100 % (P = 0.58), and clinical success was achieved in 98.3 %, 91.6 %, and 90.4 % (P < 0.0001) in the EUS-GE, ES, and surgical-GE groups, respectively. The EUS-GE group had a shorter LOS (2 days vs. 3 days vs. 5 days, P < 0.0001) and a lower AE rate than the ES and surgical-GE groups (8.6 % vs. 38.9 % vs. 27.4 %, P < 0.0001). Conclusion This large cohort study demonstrates the safety and palliation durability of EUS-GE as an alternative strategy for GOO palliation in select patients.

BACKGROUND A patient-derived organoid (PDO) platform may serve as a promising tool for translational cancer research. In this study, we evaluated PDO’s ability to predict clinical response to gastrointestinal (GI) cancers. METHODS We generated PDOs from primary and metastatic lesions of patients with GI cancers, including pancreatic ductal adenocarcinoma, colorectal adenocarcinoma, and cholangiocarcinoma. We compared PDO response with the observed clinical response for donor patients to the same treatments. RESULTS We report an approximately 80% concordance rate between PDO and donor tumor response. Importantly, we found a profound influence of culture media on PDO phenotype, where we showed a significant difference in response to standard-of-care chemotherapies, distinct morphologies, and transcriptomes between media within the same PDO cultures. CONCLUSION While we demonstrate a high concordance rate between donor tumor and PDO, these studies also showed the important role of culture media when using PDOs to inform treatment selection and predict response across a spectrum of GI cancers. TRIAL REGISTRATION Not applicable. FUNDING The Joan F. & Richard A. Abdoo Family Fund in Colorectal Cancer Research, GI Cancer program of the Mayo Clinic Cancer Center, Mayo Clinic SPORE in Pancreatic Cancer, Center of Individualized Medicine (Mayo Clinic), Department of Laboratory Medicine and Pathology (Mayo Clinic), Incyte Pharmaceuticals and Mayo Clinic Hepatobiliary SPORE, University of Minnesota-Mayo Clinic Partnership, and the Early Therapeutic program (Department of Oncology, Mayo Clinic).

Background: Neoadjuvant therapy (NAT) is used in borderline resectable/locally advanced (BR/LA) pancreatic ductal adenocarcinoma (PDAC). Anatomic imaging (CT/MRI) poorly predicts response, and biochemical (CA 19-9) markers are not useful (nonsecretors/nonelevated) in many patients. Pathologic response highly predicts survival post-NAT, but is only known postoperatively. Because metabolic imaging (FDG-PET) reveals primary tumor viability, this study aimed to evaluate our experience with preoperative FDG-PET in patients with BR/LA PDAC in predicting NAT response and survival. Methods: We reviewed all patients with resected BR/LA PDAC who underwent NAT with FDG-PET within 60 days of resection. Pre- and post-NAT metabolic (FDG-PET) and biochemical (CA 19-9) responses were dichotomized in addition to pathologic responses. We compared post-NAT metabolic and biochemical responses as preoperative predictors of pathologic responses and recurrence-free survival (RFS) and overall survival (OS). Results: We identified 202 eligible patients. Post-NAT, 58% of patients had optimization of CA 19-9 levels. Major metabolic and pathologic responses were present in 51% and 38% of patients, respectively. Median RFS and OS times were 21 and 48.7 months, respectively. Metabolic response was superior to biochemical response in predicting pathologic response (area under the curve, 0.86 vs 0.75; P <.001). Metabolic response was the only univariate preoperative predictor of OS (odds ratio, 0.25; 95% CI, 0.13–0.40), and was highly correlated ( P =.001) with pathologic response as opposed to biochemical response alone. After multivariate adjustment, metabolic response was the single largest independent preoperative predictor ( P <.001) for pathologic response (odds ratio, 43.2; 95% CI, 16.9–153.2), RFS (hazard ratio, 0.37; 95% CI, 0.2–0.6), and OS (hazard ratio, 0.21; 95% CI, 0.1–0.4). Conclusions: Among patients with post-NAT resected BR/LA PDAC, FDG-PET highly predicts pathologic response and survival, superior to biochemical responses alone. Given the poor ability of anatomic imaging or biochemical markers to assess NAT responses in these patients, FDG-PET is a preoperative metric of NAT efficacy, thereby allowing potential therapeutic alterations and surgical treatment decisions. We suggest that FDG-PET should be an adjunct and recommended modality during the NAT phase of care for these patients.

Abstract Background and study aims Endoscopic ultrasound-guided gastrojejunostomy (EUS-GJ) is an endoscopic procedure for treating gastric outlet obstruction (GOO). Limited data exist regarding the safety and efficacy of EUS-GJ in patients with malignant GOO with ascites. Thus, we aimed to study the outcomes and safety of EUS-GJ in GOO patients with vs. without ascites. Patients and methods This is a retrospective cohort study of patients with malignant GOO who underwent successful EUS-GJ at a tertiary care academic center. Primary outcomes included the efficacy and safety of EUS-GJ. Secondary outcomes included 30-day readmission, reintervention, and survival utilizing Kaplan-Meier analysis. Results A total of 55 patients (mean age of 67.0 ± 11.3 years, 40.0 % female) who underwent EUS-GJ, of whom 24 had ascites (small in 22, large in 2) were included. Clinical success was achieved in 91.7 % and 93.5 % (P = 1.00) of patients with and without ascites, respectively. A higher rate of adverse events (AEs) was noted in patients with ascites but this was not statistically significant (37.5 % vs. 19.4 %, P = 0.13). Four patients in the ascites group (16.6 %) developed clinical evidence of peritonitis or sepsis post-EUS-GJ. Eight patients with ascites developed worsening ascites within a month of EUS-GJ. In contrast, only one patient without ascites developed evidence of new ascites. The median survival of patients was not significantly different between the two groups (patients with ascites: 129 days vs. patients without ascites: 180 days, (P = 0.12). Conclusions The efficacy EUS-GJ in the presence of ascites is promising; however, the safety profile remains concerning given the high rate of AEs, specifically peritonitis and sepsis.