Comprehensive Assessment of the Intrinsic Pancreatic Microbiome.

OBJECTIVE: We sought to comprehensively profile tissue and cyst fluid in patients with benign, precancerous, and cancerous conditions of the pancreas to characterize the intrinsic pancreatic microbiome. SUMMARY BACKGROUND DATA: Small studies in pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasm (IPMN) have suggested that intra-pancreatic microbial dysbiosis may drive malignant transformation. METHODS: Pancreatic samples were collected at the time of resection from 109 patients. Samples included tumor tissue (control, n=20; IPMN, n=20; PDAC, n=19) and pancreatic cyst fluid (IPMN, n=30; SCA, n=10; MCN, n=10). Assessment of bacterial DNA by quantitative PCR and 16S ribosomal RNA gene sequencing was performed. Downstream analyses determined the relative abundances of individual taxa between groups and compared intergroup diversity. Whole-genome sequencing data from 140 patients with PDAC in the National Cancer Institute's Clinical Proteomic Tumor Analysis Consortium (CPTAC) were analyzed to validate findings. RESULTS: Sequencing of pancreatic tissue yielded few microbial reads regardless of diagnosis, and analysis of pancreatic tissue showed no difference in the abundance and composition of bacterial taxa between normal pancreas, IPMN, or PDAC groups. Low-grade dysplasia (LGD) and high-grade dysplasia (HGD) IPMN were characterized by low bacterial abundances with no difference in tissue composition and a slight increase in Pseudomonas and Sediminibacterium in HGD cyst fluid. Decontamination analysis using the CPTAC database confirmed a low-biomass, low-diversity intrinsic pancreatic microbiome that did not differ by pathology. CONCLUSIONS: Our analysis of the pancreatic microbiome demonstrated very low intrinsic biomass that is relatively conserved across diverse neoplastic conditions and thus unlikely to drive malignant transformation.

Interobserver Variability in the International Study Group for Pancreas Surgery (ISGPS)-Defined Complications After Pancreatoduodenectomy: An International Cross-Sectional Multicenter Study.

OBJECTIVE: To determine the interobserver variability for complications of pancreatoduodenectomy as defined by the International Study Group for Pancreatic Surgery (ISGPS) and others. SUMMARY BACKGROUND DATA: Good interobserver variability for the definitions of surgical complications is of major importance in comparing surgical outcomes between and within centers. However, data on interobserver variability for pancreatoduodenectomy-specific complications are lacking. METHODS: International cross-sectional multicenter study including 52 raters from 13 high-volume pancreatic centers in 8 countries on 3 continents. Per center, 4 experienced raters scored 30 randomly selected patients after pancreatoduodenectomy. In addition, all raters scored six standardized case vignettes. This variability and the 'within centers' variability were calculated for twofold scoring (no complication/grade A vs grade B/C) and threefold scoring (no complication/grade A vs grade B vs grade C) of postoperative pancreatic fistula (POPF), post-pancreatoduodenectomy hemorrhage (PPH), chyle leak (CL), bile leak (BL), and delayed gastric emptying (DGE). Interobserver variability is presented with Gwet's AC-1 measure for agreement. RESULTS: Overall, 390 patients after pancreatoduodenectomy were included. The overall agreement rate for the standardized cases vignettes for twofold scoring was 68% (95%-CI: 55%-81%, AC1 score: moderate agreement) and for threefold scoring 55% (49%-62%, AC1 score: fair agreement). The mean 'within centers' agreement for twofold scoring was 84% (80%-87%, AC1 score; substantial agreement). CONCLUSION: The interobserver variability for the ISGPS defined complications of pancreatoduodenectomy was too high even though the 'within centers' agreement was acceptable. Since these findings will decrease the quality and validity of clinical studies, ISGPS has started efforts aimed at reducing the interobserver variability.

Initial Report: Personalized Circulating Tumor DNA and Survival in Patients with Resectable Pancreatic Cancer.

ABSTRACT: BACKGROUND: Pancreatic adenocarcinoma (PDAC) is highly lethal with up to 80% of resected patients experiencing disease recurrence within 2 years (Watanabe, Nakamura, Kimura et al in Int J Mol Sci 23(19):11521, 2022). Cross-sectional imaging and serum tumor markers are used for monitoring post-operative recurrence; however, both have significant limitations (Edland, Tjensvoll, Oltedal et al in Mol Oncol 17:1857-1870, 2023). Circulating tumor DNA (ctDNA) has emerged as a valuable prognostic tool to measure molecular residual disease (MRD) and predict recurrence in solid tumors (Watanabe, Nakamura, Kimura et al in Int J Mol Sci 23(19):11521, 2022). In this study, we evaluated the feasibility of a personalized, tumor-informed ctDNA assay to detect recurrence prior to standard surveillance tools in patients with PDAC. PATIENTS AND METHODS: After Institutional Review Board (IRB) approval (Pro00106870), we assessed serial ctDNA measurements (n = 177) from 35 patients with resectable PDAC treated by either upfront resection or neoadjuvant chemotherapy. Plasma samples (median 4 ml, interquartile range 0.6-5.9 ml) were isolated from blood collected in EDTA tubes and banked at diagnosis, during neoadjuvant therapy if applicable, on the day of surgery, and every 2-3 months postoperatively. A tumor-informed assay (Signatera™, Natera, Inc.) that tracks up to 16 individual-specific, somatic single nucleotide variants in the corresponding patient's plasma samples were used for ctDNA detection. Survival was calculated using Kaplan-Meier curves, and significance was determined with the log-rank test. RESULTS: Personalized ctDNA assays were successfully designed for all patients (with 32/35 patients having 16-plex assays). Median follow-up from initial treatment was 13 months (range 1-26 months; Table 1). ctDNA-positivity at any time point was observed in 40% (14/35) of patients. During the follow-up period, 18 patients (51%) developed radiographic evidence of recurrence after a median of 9 months of follow-up (range 1-26 months). At the time of radiographic recurrence, 50% (9/18) of patients were ctDNA-positive. During the immediate postoperative period (up to 9 weeks post-surgery), RFS and OS were significantly inferior in patients who were ctDNA-positive versus ctDNA-negative (RFS 97 versus 297 days, p < 0.001; OS 110 versus 381 days, p < 0.001; Fig. 1). Table 1 Cohort demographics (N = 35); patient demographics, tumor characteristics, and survival Gender (%) Female 17 (49%) Male 18 (51%) Median age (IQR) 70 years (65-75 years) Neoadjuvant treatment (%) 11 (31%) Median sample plasma volume (IQR) 4.0 mL (0.6-5.9 mL) Median follow-up (range) 13 months (1-26 months) Median initial CA 19-9 in U/mL (IQR) 56 (18-160) Median tumor size in cm (IQR) 2.5 (1.8-3.3) Median number of positive lymph nodes (IQR) 1 (0-3) Median recurrence-free survival 9.4 months Median overall survival N/A (not reached) Fig. 1 a Overview plot showing longitudinal ctDNA status, treatment regimen, and clinical outcomes for each patient (N = 35); median follow-up from the start of the neoadjuvant therapy/surgery was 13 months (range 1-26 months); ctDNA at any time point was 40% (14/35); out of the 35 patients, 18 (51%) developed radiographic evidence of recurrence (median RFS: 9 months), and of these 18 patients with clinical recurrence, 9 (50%) were ctDNA-positive and the remaining ctDNA-negative; notably, all ctDNA-negative patients with recurrence had suboptimal plasma volume available for ctDNA analysis; b, c Kaplan-Meier estimates representing the association of ctDNA status with (b) RFS and (c) OS, at MRD time point (9 weeks post-surgery) DISCUSSION: Our study demonstrates the feasibility of tumor-informed ctDNA-based MRD testing in resectable PDAC and shows that MRD detected by ctDNA within the immediate postoperative period portends a dismal prognosis. This information is valuable for both patients and clinicians in setting prognostic expectations.

Evolution of Initial Treatment for Desmoid Tumors.

INTRODUCTION: Desmoid tumors (DTs) are rare, fibroblastic cell proliferations that can exhibit locally aggressive behavior but lack metastatic potential. Initial management has traditionally involved upfront resection; however, contemporary guidelines and expert panels have increasingly advocated for prioritizing active surveillance strategies. METHODS: A single-institution, retrospective chart review identified all patients diagnosed with a primary DT at any site from 2007 to 2020. The primary outcome was the initial management strategy over time. Secondary outcomes included treatment-free survival (TFS) and time to treatment (TTT) for those undergoing active surveillance, as well as recurrence-free survival (RFS) and time to recurrence for those undergoing resection. RESULTS: Overall, 103 patients were included, with 68% female and a median follow-up of 44 months [24-74]. The most common tumor locations included the abdominal wall (27%), intra-abdominal/mesenteric (25%), chest wall (19%), and extremity (10%). Initial management included resection (60%), systemic therapy (20%), active surveillance (18%), and cryoablation (2%). Rates of surgical resection significantly decreased (p < 0.001) over time, from 69.6% prior to 2018 to 29.2% after 2018. For those treated with upfront resection, 5-year RFS was 41.2%, and for patients undergoing initial active surveillance, TFS was 66.7% at 2 years, with a median TTT of 4 months [4-10]. CONCLUSIONS: This single-institution cohort at a tertiary medical center spanning over a decade demonstrates the transition to active surveillance for initial management of DTs, and highlights salient metrics in the era of surveillance. This trend mirrors recommended treatment strategies by expert panels and consensus guidelines.

Simple versus radical cholecystectomy and survival for pathologic stage T1B gallbladder cancer.

BACKGROUND: Radical cholecystectomy is recommended for T1B and greater gallbladder cancer, however, there are conflicting reports on the utility of extended resection for T1B disease. Herein, we characterize outcomes following simple and radical cholecystectomy for pathologic stage T1B gallbladder cancer. METHODS: The National Cancer Database (NCDB) was queried for patients with pathologic T1B gallbladder cancer diagnosed from 2004 to 2018. Patients were stratified by surgical management. Overall survival (OS) was compared with Kaplan-Meier and multivariable Cox proportional hazards methods. RESULTS: Altogether, 950 patients were identified with pathologic T1B gallbladder cancer: 187 (19.7 %) receiving simple and 763 (80.3 %) radical cholecystectomy. Median OS was 89.5 (95 % CI 62.5-137) and 91.4 (95 % CI 75.9-112) months for simple and radical cholecystectomy, respectively (log-rank p = 0.55). Receipt of simple cholecystectomy was not associated with greater hazard of mortality compared to radical cholecystectomy (HR 1.23, 95 % CI 0.95-1.59, p = 0.12). DISCUSSION: In this analysis, we report comparable outcomes with simple cholecystectomy among patients with pathologic T1B gallbladder cancer. These findings suggest that highly selected patients, such as those with R0 resection and imaging at low risk for residual disease and/or nodal metastasis, may not benefit from extended resection; however, radical cholecystectomy remains standard of care until prospective validation can be achieved.

Comparing Survival After Resection, Ablation, and Radiation in Small Intrahepatic Cholangiocarcinoma.

BACKGROUND: Hepatectomy is the cornerstone of curative-intent treatment for intrahepatic cholangiocarcinoma (ICC). However, in patients unable to be resected, data comparing efficacy of alternatives including thermal ablation and radiation therapy (RT) remain limited. Herein, we compared survival between resection and other liver-directed therapies for small ICC within a national cancer registry. PATIENTS AND METHODS: Patients with clinical stage I-III ICC < 3 cm diagnosed 2010-2018 who underwent resection, ablation, or RT were identified in the National Cancer Database. Overall survival (OS) was compared using Kaplan-Meier and multivariable Cox proportional hazards methods. RESULTS: Of 545 patients, 297 (54.5%) underwent resection, 114 (20.9%) ablation, and 134 (24.6%) RT. Median OS was similar between resection and ablation [50.5 months, 95% confidence interval (CI) 37.5-73.9; 39.5 months, 95% CI 28.7-58.4, p = 0.14], both exceeding that of RT (20.9 months, 95% CI 14.1-28.3). RT patients had high rates of stage III disease (10.4% RT vs. 1.8% ablation vs. 11.8% resection, p < 0.001), but the lowest rates of chemotherapy utilization (9.0% RT vs. 15.8% ablation vs. 38.7% resection, p < 0.001). In multivariable analysis, resection and ablation were associated with reduced mortality compared with RT [hazard ratio (HR) 0.44, 95% CI 0.33-0.58 and HR 0.53, 95% CI 0.38-0.75, p < 0.001, respectively]. CONCLUSION: Resection and ablation were associated with improved survival in patients with ICC < 3 cm compared with RT. Acknowledging confounders, anatomic constraints of ablation, limitations of available data, and need for prospective study, these results favor ablation in small ICC where resection is not feasible.

Trends in Receipt of Adjuvant Chemotherapy and its Impact on Survival in Resected Biliary Tract Cancers.

BACKGROUND: Resection remains the cornerstone of curative-intent treatment for biliary tract cancers (BTCs). However, recent randomized data also support a role for adjuvant chemotherapy (AC). This study aimed to characterize trends in the use of AC and subsequent outcomes in gallbladder cancer and cholangiocarcinoma (CCA). METHODS: The National Cancer Database (NCDB) was queried for patients with resected, localized BTC from 2010 to 2018. Trends in AC were compared among BTC subtypes and stages of disease. Multivariable logistic regression was used to identify factors associated with receipt of AC. Survival analysis was performed with Kaplan-Meier and multivariable Cox proportional hazards methods. RESULTS: The study identified 7039 patients: 4657 (66%) with gallbladder cancer, 1159 (17%) with intrahepatic CCA (iCCA), and 1223 (17%) with extrahepatic CCA (eCCA). Adjuvant chemotherapy was administered to 2172 (31%) patients, increasing from 23% in 2010 to 41% in 2018. Factors associated with AC included female sex, year of diagnosis, private insurance, care at an academic center, higher education, eCCA (vs iCCA), positive margins, and stage II or III disease (vs stage I). Alternatively, increasing age, higher comorbidity score, gallbladder cancer (vs iCCA), and farther travel distance for treatment were associated with reduced odds of AC. Overall, AC was not associated with a survival advantage. However, subgroup analysis showed that AC was associated with a significant reduction in mortality among patients with eCCA. CONCLUSIONS: Among the patients with resected BTC, those who received AC were in the minority. In the context of recent randomized data and evolving recommendations, emphasis on guideline concordance with a focus on at-risk populations may improve outcomes.

Tumor size and survival in intrahepatic cholangiocarcinoma treated with surgical resection or ablation.

OBJECTIVES: We performed a retrospective analysis within a national cancer registry on outcomes following resection or ablation for intrahepatic cholangiocarcinoma (iCCA). METHODS: The National Cancer Database was queried for patients with clinical stage I-III iCCA diagnosed during 2010-2018, who underwent resection or ablation. Overall survival (OS) was compared with Kaplan-Meier and multivariable Cox proportional hazards methods. RESULTS: Of 2140 patients, 1877 (87.7%) underwent resection and 263 (12.3%) underwent ablation, with median tumor sizes of 5.5 and 3 cm, respectively. Overall, resection was associated with greater median OS (41.2 months (95% confidence interval [95% CI]: 37.6-46.2) vs. 28 months (95% CI: 15.9-28.6) on univariable analysis (p < 0.0001). There was no significant difference on multivariable analysis (p = 0.42); however, there was a significant interaction between tumor size and management. On subgroup analysis of patients with tumors <3 cm, there was no difference in OS between resection versus ablation. However, ablation was associated with increased mortality for tumors ≥3 cm. CONCLUSION: Although resection is associated with improved OS for tumors ≥3 cm, we observed no difference in survival between management strategies for tumors < 3 cm. Ablation may be an alternative therapeutic strategy for small iCCA, particularly in patients at risk for high surgical morbidity.

The Impact of Age in the Treatment of Non-comorbid Patients with Rectal Cancer: Survival Outcomes from the National Cancer Database.

BACKGROUND: Multimodal therapy has improved survival outcomes for rectal cancer (RC) significantly with an exemption for older patients. We sought to assess whether older non-comorbid patients receive substandard oncological treatment for localized RC referring to the National Comprehensive Cancer Network (NCCN) guidelines and whether it affects survival outcomes. METHODS: This is a retrospective study using patient data from the National Cancer Data Base (NCDB) for histologically confirmed RC from 2002 to 2014. Non-comorbid patients between ≥50 and ≤85 years and defined treatment for localized RC were included and assigned to a younger (<75 years) and an older group (≥75 years). Treatment approaches and their impact on relative survival (RS) were analyzed using loess regression models and compared between both groups. Furthermore, mediation analysis was performed to measure the independent relative effect on age and other variables on RS. Data were assessed using the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) checklist. RESULTS: Of 59,769 included patients, 48,389 (81.0%) were assigned to the younger group (<75 years). Oncologic resection was performed in 79.6% of the younger patients compared to 67.2% of the older patients (p < 0.001). Chemotherapy (74.3% vs. 56.1%) and radiotherapy (72.0% vs. 58.1%) were provided less often in older patients, respectively (p < 0.001). Increasing age was associated with enhanced 30- and 90-day mortality with 0.6% and 1.1% in the younger and 2.0% and 4.1% in the elderly group (p < 0.001) and worse RS rates [multivariable adjusted HR: 1.93 (95% CI 1.87-2.00), p < 0.001]. Adherence to standard oncological therapy resulted in a significant increase in 5-year RS (multivariable adjusted HR: 0.80 (95% CI 0.74-0.86), p < 0.001). Mediation analysis revealed that RS was mainly affected by age itself (84%) rather than the choice of therapy. CONCLUSIONS: The likelihood to receive substandard oncological therapy increases in the older population and negatively affects RS. Since age itself has a major impact on RS, better patient selection should be performed to identify those that are potentially eligible for standard oncological care regardless of their age.

Patterns and Impact of Fragmented Care in Stage II and III Gastric Cancer.

BACKGROUND: Optimal management of stage II/III gastric cancer requires multidisciplinary care, often necessitating treatment at more than one facility. We aimed to determine patterns of "fragmented" care and its impact on outcomes, including concordance with National Comprehensive Cancer Network (NCCN) guidelines and overall survival. METHODS: The 2006-2016 National Cancer Database was queried for patients with clinical stage II/III gastric adenocarcinoma who received preoperative therapy in addition to surgery. Patients were stratified based on whether surgery and chemotherapy/chemoradiation were performed at one versus multiple facilities (termed "coordinated" and "fragmented" care, respectively). Multivariable logistic regression was performed to identify factors associated with fragmented care. Survival was compared using Kaplan-Meier and Cox proportional hazards methods. RESULTS: Overall, 2033 patients met study criteria: 1043 (51.3%) received coordinated care and 990 (48.7%) fragmented care. There was no significant difference in time to surgery or pathologic upstaging by care structure. On adjusted analysis, factors associated with receipt of fragmented care included increasing age and distance traveled to the treating facility. Factors associated with coordinated care included metropolitan residence and treatment at academic and high-volume centers. Fragmented care was associated with a reduction in guideline-preferred perioperative chemotherapy (odds ratio [OR] 0.78, 95% confidence interval [CI] 0.63-0.97, p = 0.02) and increased mortality (HR 1.16, 95% CI 1.00-1.34, p = 0.05). CONCLUSIONS: For patients with stage II/III gastric cancer, fragmented care is associated with inferior outcomes, including a reduction in preferred perioperative treatment and survival. Further work is needed to ensure equitable outcomes among patients as complex cancer care becomes more regionalized.

Multidimensional Immunophenotyping of Intraductal Papillary Mucinous Neoplasms Reveals Novel T Cell and Macrophage Signature.

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMN) are the only radiographically identifiable precursor to pancreatic adenocarcinoma, yet little is known about how these lesions progress to cancer. Inflammation has been associated with dysplastic progression; however, the cause and composition of this inflammation remains poorly characterized. We sought to comprehensively profile immune cell infiltration using parallel spatial transcriptomic and flow cytometric techniques. METHODS: Twelve patients with resected IPMN exhibiting both high-grade dysplasia (HGD) and low-grade dysplasia (LGD) were selected for spatial transcriptomics (NanoString GeoMx). Immune (CD45+), epithelial (PanCK+), and stromal (SMA+) compartments were analyzed separately using the GeoMx NGS Pipeline. An additional 11 patients resected for IPMN of varying degrees of dysplasia underwent immunophenotyping using flow cytometry (DURAClone IM). RESULTS: Spatial transcriptomics revealed that T cells represent the dominant immune cell within IPMN stroma, which was confirmed by flow cytometry (56%). Spatial profiling found that the T-cell infiltrate was significantly higher in regions of LGD compared with HGD (62% vs. 50%, p = 0.038). Macrophages were the only other immune cell type with > 10% abundance, yet conversely, were generally more abundant in regions of HGD compared to LGD (19% vs. 11%, p = 0.058). Correspondingly, immune cells within regions of HGD demonstrated transcriptional upregulation of genes associated with macrophage activity including secretion (CXCL1) and phagocytosis (C1QA, C1S, C4B). CONCLUSIONS: IPMN immune infiltrate is primarily composed of T cells and macrophages. Regions of HGD appear to be relatively deplete of T cells and show a trend toward macrophage enrichment compared with regions of LGD.

Impact of enhanced recovery protocols after pancreatoduodenectomy: meta-analysis.

BACKGROUND: This individual-patient data meta-analysis investigated the effects of enhanced recovery after surgery (ERAS) protocols compared with conventional care on postoperative outcomes in patients undergoing pancreatoduodenectomy. METHODS: The Cochrane Library, MEDLINE, Embase, Scopus, and Web of Science were searched systematically for articles reporting outcomes of ERAS after pancreatoduodenectomy published up to August 2020. Comparative studies were included. Main outcomes were postoperative functional recovery elements, postoperative morbidity, duration of hospital stay, and readmission. RESULTS: Individual-patient data were obtained from 17 of 31 eligible studies comprising 3108 patients. Time to liquid (mean difference (MD) -3.23 (95 per cent c.i. -4.62 to -1.85) days; P < 0.001) and solid (-3.84 (-5.09 to -2.60) days; P < 0.001) intake, time to passage of first stool (MD -1.38 (-1.82 to -0.94) days; P < 0.001) and time to removal of the nasogastric tube (3.03 (-4.87 to -1.18) days; P = 0.001) were reduced with ERAS. ERAS was associated with lower overall morbidity (risk difference (RD) -0.04, 95 per cent c.i. -0.08 to -0.01; P = 0.015), less delayed gastric emptying (RD -0.11, -0.22 to -0.01; P = 0.039) and a shorter duration of hospital stay (MD -2.33 (-2.98 to -1.69) days; P < 0.001) without a higher readmission rate. CONCLUSION: ERAS improved postoperative outcome after pancreatoduodenectomy. Implementation should be encouraged.

Enhanced recovery protocols consist of interdisciplinary interventions aimed at standardizing care and reducing the impact of surgical stress. They often include a short period of preoperative fasting during the night before surgery, early removal of lines and surgical drains, early food intake and mobilization out of bed on the day of surgery. This study gives a summary of reports assessing such care protocols in patients undergoing pancreatic head surgery, and assesses the impact of these protocols on functional recovery in an analysis of individual-patient data. The study revealed the true benefits of enhanced recovery protocols, including shorter time to food intake, earlier bowel activity, fewer complications after surgery, and a shorter hospital stay compared with conventional care.

No Difference in Survival between Neo-Adjuvant Chemotherapy and Neo-Adjuvant Chemoradiation Therapy in Gastric Cardia Cancer Patients: A Contemporary View from the National Cancer Database.

INTRODUCTION: Both neo-adjuvant chemoradiation therapy (NACRT) and neo-adjuvant chemotherapy (NAC), in addition to surgical resection of gastric cardia cancer, improves survival outcomes. We assessed whether NACRT or NAC had superior overall survival (OS) and relative survival (RS) outcomes using the National Cancer Database (NCDB). METHODS: The NCDB from 2006 to 2014 was reviewed to identify non-metastatic adult gastric cardia cancer patients who underwent surgical resection and received NACRT or NAC. Advanced statistical models were applied to assess survival outcomes. RESULTS: Of the 5,371 patients included, 4,520 (84.2%) were male, the mean age was 61.2 years (SD 10.0), 4,229 (78.7%) underwent NACRT, and 1,142 (21.3%) underwent NAC. NACRT patients more often had an R0 resection compared to NAC (91.4 vs. 86.6%, p < 0.001, respectively). Univariate 5-year OS rates were 40.0% (95% CI 38.2-41.8) for NACRT and 40.1% (37.0-43.6) for NAC (p = 0.302). No differences in OS for NAC vs. NACRT were found after multivariable analysis (hazard ratio [HR] 0.95, 95% CI 0.86-1.05, p = 0.290). There were no survival differences after stepwise, propensity score, RS analyses, nor after near-far-matching (HR 0.94, 95% CI 0.82-1.07, p = 0.332). CONCLUSIONS: NAC or NACRT yield the same survival outcome for patients with resectable gastric cardia cancer. These data support the need for randomized controlled trials comparing the 2 regimens head-to-head.

Role of lymphadenectomy, adjuvant chemotherapy, and treatment at high-volume centers in patients with resected pancreatic cancer-a distinct view on lymph node yield.

PURPOSE: While the importance of lymphadenectomy is well-established for patients with resectable pancreatic cancer, its direct impact on survival in relation to other predictive factors is still ill-defined. METHODS: The National Cancer Data Base 2006-2015 was queried for patients with resected pancreatic adenocarcinoma (stage IA-IIB). Patients were dichotomized into the following two groups, those with 1-14 resected lymph nodes and those with ≥ 15. Optimal number of resected lymph nodes and the effect of lymphadenectomy on survival were assessed using various statistical modeling techniques. Mediation analysis was performed to differentiate the direct and indirect effect of lymph node resection on survival. RESULTS: A total of 21,912 patients were included; median age was 66 years (IQR 59-73), 48.9% were female. Median number of resected lymph nodes was 15 (IQR 10-22), 10,163 (46.4%) had 1-14 and 11,749 (53.6%) had ≥ 15 lymph nodes retrieved. Lymph node positivity increased by 4.1% per lymph node up to eight examined lymph nodes, and by 0.6% per lymph node above eight. Five-year overall survival was 17.9%. Overall survival was better in the ≥ 15 lymph node group (adjusted HR 0.91, CI 0.88-0.95, p < 0.001). On a continuous scale, survival improved with increasing LNs collected. Patients who underwent adjuvant chemotherapy and were treated at high-volume centers had improved overall survival compared with their counterparts (adjusted HR 0.59, CI 0.57-0.62, p < 0.001; adjusted HR 0.86, CI 0.83-0.89, p < 0.001, respectively). Mediation analysis revealed that lymphadenectomy had only 18% direct effect on improved overall survival, while 82% of its effect were mediated by other factors like treatment at high-volume hospitals and adjuvant chemotherapy. DISCUSSION: While higher number of resected lymph nodes increases lymph node positivity and is associated with better overall survival, most of the observed survival benefit is mediated by chemotherapy and treatment at high-volume centers.

Soft Tissue Sarcoma of the Extremities: What Is the Value of Treating at High-volume Centers?

BACKGROUND: For many cancer types, survival is improved when patients receive management at treatment centers that encounter high numbers of patients annually. This correlation may be more important with less common malignancies such as sarcoma. Existing evidence, however, is limited and inconclusive as to whether facility volume may be associated with survival in soft tissue sarcoma. QUESTIONS/PURPOSES: The purpose of this study was to examine the association between facility volume and overall survival in patients with soft tissue sarcoma of the extremities. In investigating this aim, we sought to (1) examine differences in the treatment characteristics of high- and low-volume facilities; (2) estimate the 5-year survival by facility volume; and (3) examine the association between facility volume and of traveling a further distance to a high-volume center and overall survival when controlling for confounding factors. METHODS: The largest sarcoma patient registry to date is contained within the National Cancer Database (NCDB) and captures > 70% of new cancer diagnoses annually. We retrospectively analyzed 25,406 patients with soft tissue sarcoma of the extremities in the NCDB from 1998 through 2012. Patients were stratified based on per-year facility sarcoma volume and we used univariate comparisons and multivariate proportional hazards analyses to correlate survival measures with facility volume and various other patient-, tumor-, and treatment-related factors. First, we evaluated long-term survival for all variables using the Kaplan-Meier method with statistical comparisons based on the log-rank test. Multiple patient, tumor, and treatment characteristics were compared between the two facility-volume groups and then included them in the multivariate proportional hazards model. Of the 25,406 patients analyzed, 3310 were treated at high-volume centers (≥ 20 patients annually) and 22,096 were treated at low-volume centers. Patient demographics were generally not different between both patient cohorts, although patients treated at high-volume centers were more likely to have larger and higher grade tumors (64% versus 56% size ≥ 5 cm, 28% versus 14% undifferentiated grade, p < 0.001). RESULTS: When controlling for patient, tumor, and treatment characteristics in a multivariate proportional hazards analysis, patients treated at high-volume facilities had an overall lower risk of mortality than those treated at low-volume centers (hazard ratio, 0.81 [0.75-0.88], p < 0.001). Patients treated at high-volume centers were also less likely to have positive margins (odds ratio [OR], 0.59 [0.52-0.68], p < 0.001) and in patients who received radiation, those treated at high-volume centers were more likely to have radiation before surgery (40.5% versus 21.7%, p < 0.001); there was no difference in the type of surgery performed (resection versus amputation) (OR, 1.01 [0.84-1.23], p = 0.883). CONCLUSIONS: With the largest patient cohort to date, this database review suggests that certain patients with soft tissue sarcoma of the extremities, particularly those with large high-grade tumors, may benefit from treatment at high-volume centers. Further investigation is necessary to help improve the referral of appropriate patients to high-volume sarcoma centers and to increase the treatment capacity of and access to such centers. LEVEL OF EVIDENCE: Level III, therapeutic study.

Underutilization of surgical resection in patients with pancreatic acinar cell carcinoma.

BACKGROUND: Pancreatic acinar cell carcinoma (pACC) is a rare malignancy and surgical utilization has been historically low in these patients. Contemporary outcomes for this patient population remain unknown. METHODS: The 1998-2012 National Cancer Data Base was queried for baseline characteristics in patients with pACC. Patients with potentially operable disease (stage I/II) were grouped by surgical resection. Multivariable logistic regression was used to predict factors associated with resection. Survival was estimated using Kaplan-Meier analysis. A proportional hazards model identified factors associated with overall survival. RESULTS: 980 patients were identified. Mean age at diagnosis was 64 years. Tumors were more common in men (68%), white patients (88%), and within the pancreatic head (57%). Thirty-four percent of patients with localized disease failed to undergo resection. Five-year survival was higher among patients who underwent resection (42% vs. 9%, p < 0.001). In patients with resectable disease, male sex, older age, black race, tumors within the pancreatic head, lower grade tumors and treatment at non-academic centers are associated with failure to undergo surgery. CONCLUSION: Patients with localized pACC have increased survival after resection. However, in this contemporary analysis, resection continues to be underutilized and new efforts to increase resection rates should be undertaken.