Multiinstitutional Validation Study of Cyst Fluid Protein Biomarkers in Patients With Cystic Lesions of the Pancreas.

OBJECTIVE: Prospective evaluation of 2 clinical-molecular models in patients with unknown pathology who underwent endoscopic ultrasound with fine-needle aspiration (EUS-FNA) for a cystic lesion of the pancreas. SUMMARY OF BACKGROUND DATA: Preoperative prediction of histologic subtype (mucinous vs nonmucinous) and grade of dysplasia in patients with pancreatic cystic neoplasms is challenging. Our group has previously published 2 clinical-molecular nomograms for intraductal papillary mucinous neoplasms (IPMN) that incorporated both clinical/radiographic features and cyst fluid protein markers (sFASL, CA72-4, MMP9, IL-4). METHODS: This multiinstitutional study enrolled patients who underwent EUS-FNA for a cystic lesion of the pancreas. Treatment recommendations regarding resection were based on standard clinical, radiographic, and endoscopic features. Predicted probabilities of high-risk IPMN (high-grade dysplasia/invasive cancer) were calculated using the previously developed clinical-molecular nomograms. RESULTS: Cyst fluid was obtained from 100 patients who underwent diagnostic EUS-FNA. Within this group there were 35 patients who underwent resection, and 65 were monitored radiographically. Within the group that underwent resection, 26 had low-risk IPMN or benign non-IPMN lesions, and 9 had high-risk IPMN. Within the surveillance group, no patient progressed to resection or developed cancer after a median follow-up of 12months (range: 0.5-38). Using the clinical/radiographic nomogram alone, 2 out of 9 patients with high-risk IPMN had a predicted probability >0.5. In the clinical-molecular models, 6 of 9 patients in model 1, and 6 of 9 in model 2, had scores >0.5. CONCLUSIONS: This prospective study of patients with unknown cyst pathology further demonstrates the importance of cyst fluid protein analysis in the preoperative identification of patients with high-risk IPMN. Longer follow-up is necessary to determine if this model will be useful in clinical practice.

Microscopic size measurements in post-neoadjuvant therapy resections of pancreatic ductal adenocarcinoma (PDAC) predict patient outcomes.

AIMS: Pancreatic ductal adenocarcinomas (PDACs) are increasingly being treated with neoadjuvant therapy. However, the American Joint Committee on Cancer (AJCC) 8th edition T staging based on tumour size does not reflect treatment effect, which often results in multiple, small foci of residual tumour in a background of mass-forming fibrosis. Thus, we evaluated the performance of AJCC 8th edition T staging in predicting patient outcomes by the use of a microscopic tumour size measurement method. METHODS AND RESULTS: One hundred and six post-neoadjuvant therapy pancreatectomies were reviewed, and all individual tumour foci were measured. T stages based on gross size with microscopic adjustment (GS) and the largest single microscopic focus size (MFS) were examined in association with clinicopathological variables and patient outcomes. Sixty-three of 106 (59%) were locally advanced; 78% received FOLFIRINOX treatment. The average GS and MFS were 25 mm and 11 mm, respectively; nine cases each were classified as T0, 35 and 85 cases as T1, 42 and 12 cases as T2, and 20 and 0 cases as T3, based on the GS and the MFS, respectively. Higher GS-based and MFS-based T stages were significantly associated with higher tumour regression grade, lymphovascular and perineural invasion, and higher N stage. Furthermore, higher MFS-based T stage was significantly associated with shorter disease-free survival (DFS) (P < 0.001) and shorter overall survival (OS) (P = 0.002). GS was significantly associated with OS (P = 0.046), but not with DFS. CONCLUSIONS: In post-neoadjuvant therapy PDAC resections, MFS-based T staging is superior to GS-based T staging for predicting patient outcomes, suggesting that microscopic measurements have clinical utility beyond the conventional use of GS measurements alone.

Impact of adjuvant therapy in patients with invasive intraductal papillary mucinous neoplasms of the pancreas.

BACKGROUND: There is limited data on the efficacy of adjuvant therapy (AT) in patients with invasive intraductal papillary mucinous neoplasms of the pancreas (IPMN). This single center retrospective cohort study aims to assess the impact of AT on survival in these patients. METHODS: Patients undergoing surgery for invasive IPMN between 1993 and 2018 were included in the study. We compared the clinicopathologic features and evaluated overall survival (OS) using multivariate Cox regression adjusting for adjuvant therapy, age, T and N stage, perineural and lymphovascular invasion. We also assessed survival differences between surgery alone and AT in node negative (N0) and node positive (N+) subgroups. RESULTS: 103 patients were included in the study; 69 underwent surgery alone while 34 also received AT. Patients in the AT group were significantly younger, presented at higher T and N stages and had more perineural and lymphovascular invasion. Median OS in the surgery alone group was 134 months and 65 months in the AT group, p = 0.052. On multivariate analysis, AT was not associated with improved OS; hazard ratio (HR) = 1.03 (0.52-2.05). In N0 patients, compared to surgery alone, AT was associated with a worse median OS (65 vs 167 months, p = 0.03), whereas in N+ patients there was a non-significant improvement (50.5 vs 20.4 months, p = 0.315). CONCLUSION: AT did not improve survival in the overall cohort even after multivariate analysis. N0 patients have excellent survival, and AT should probably be avoided in them, whereas it may be considered in patients with N+ disease.

Novel Methylated DNA Markers Discriminate Advanced Neoplasia in Pancreatic Cysts: Marker Discovery, Tissue Validation, and Cyst Fluid Testing.

OBJECTIVES: Pancreatic cystic lesions (PCLs) may be precancerous. Those likely to harbor high-grade dysplasia (HGD) or pancreatic cancer (PC) are targets for surgical resection. Current algorithms to predict advanced neoplasia (HGD/PC) in PCLs lack diagnostic accuracy. In pancreatic tissue and cyst fluid (CF) from PCLs, we sought to identify and validate novel methylated DNA markers (MDMs) that discriminate HGD/PC from low-grade dysplasia (LGD) or no dysplasia (ND). METHODS: From an unbiased whole-methylome discovery approach using predefined selection criteria followed by multistep validation on case (HGD or PC) and control (ND or LGD) tissues, we identified discriminant MDMs. Top candidate MDMs were then assayed by quantitative methylation-specific polymerase chain reaction on archival CF from surgically resected PCLs. RESULTS: Of 25 discriminant MDMs identified in tissue, 13 were selected for validation in 134 CF samples (21 cases [8 HGD, 13 PC], 113 controls [45 ND, 68 LGD]). A tree-based algorithm using 2 CF-MDMs (TBX15, BMP3) achieved sensitivity and specificity above 90%. Discrimination was significantly better by this CF-MDM panel than by mutant KRAS or carcinoembryonic antigen, with areas under the receiver operating characteristic curve of 0.93 (95% confidence interval: 0.86-0.99), 0.71 (0.57-0.85), and 0.72 (0.60-0.84), respectively. Cutoffs for the MDM panel applied to an independent CF validation set (31 cases, 56 controls) yielded similarly high discrimination, areas under the receiver operating characteristic curve = 0.86 (95% confidence interval: 0.77-0.94, P = 0.2). DISCUSSION: Novel MDMs discovered and validated in tissue accurately identify PCLs harboring HGD/PC. A panel of 2 MDMs assayed in CF yielded results with potential to enhance current risk prediction algorithms. Prospective studies are indicated to optimize and further evaluate CF-MDMs for clinical use.

Single-nucleus and spatial transcriptome profiling of pancreatic cancer identifies multicellular dynamics associated with neoadjuvant treatment.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal and treatment-refractory cancer. Molecular stratification in pancreatic cancer remains rudimentary and does not yet inform clinical management or therapeutic development. Here, we construct a high-resolution molecular landscape of the cellular subtypes and spatial communities that compose PDAC using single-nucleus RNA sequencing and whole-transcriptome digital spatial profiling (DSP) of 43 primary PDAC tumor specimens that either received neoadjuvant therapy or were treatment naive. We uncovered recurrent expression programs across malignant cells and fibroblasts, including a newly identified neural-like progenitor malignant cell program that was enriched after chemotherapy and radiotherapy and associated with poor prognosis in independent cohorts. Integrating spatial and cellular profiles revealed three multicellular communities with distinct contributions from malignant, fibroblast and immune subtypes: classical, squamoid-basaloid and treatment enriched. Our refined molecular and cellular taxonomy can provide a framework for stratification in clinical trials and serve as a roadmap for therapeutic targeting of specific cellular phenotypes and multicellular interactions.

Association Between Pancreatic Fistula and Long-term Survival in the Era of Neoadjuvant Chemotherapy.

Importance: In the past decade, the use of neoadjuvant therapy (NAT) has increased for patients with borderline and locally advanced pancreatic ductal adenocarcinoma (PDAC). Data on pancreatic fistula and related overall survival (OS) in this setting are limited. Objective: To compare postoperative complications in patients undergoing either upfront resection or pancreatectomy following NAT, focusing on clinically relevant postoperative pancreatic fistula (CR-POPF) and potential associations with OS. Design, Setting, and Participants: This retrospective cohort study was conducted on data from patients who underwent pancreatic resection for PDAC at the Massachusetts General Hospital from January 1, 2007, to December 31, 2017. Exposures: Pancreatic cancer surgery with or without NAT. Main Outcomes and Measures: Overall morbidity and CR-POPF rates were compared between NAT and upfront resection. Factors associated with CR-POPF were assessed with univariate and multivariate analysis. Survival data were analyzed by Kaplan-Meier curves and a Cox proportional hazards regression model. Results: Of 753 patients, 364 were men (48.3%); median (interquartile range) age was 68 (61-75) years. A total of 346 patients (45.9%) received NAT and 407 patients (54.1%) underwent upfront resection. At pathologic examination, NAT was associated with smaller tumor size (mean [SD], 26.0 [15.3] mm vs 32.7 [14.4] mm; P < .001), reduced nodal involvement (102 [25.1%] vs 191 [55.2%]; P < .001), and higher R0 rates (257 [74.3%] vs 239 [58.7%]; P < .001). There were no significant differences in severe complication rate or 90-day mortality. The rate of CR-POPF was 3.6-fold lower in patients receiving NAT vs upfront resection (13 [3.8%] vs 56 [13.8%]; P < .001). In addition, factors associated with CR-POPF changed after NAT, and only soft pancreatic texture was associated with a higher risk of CR-POPF (38.5% vs 6.3%; P < .001). Survival analysis showed no differences between patients with or without CR-POPF after upfront resection (26 vs 25 months; P = .66), but after NAT, a worse overall survival rate was observed in patients with CR-POPF (17 vs 34 months; P = .002). This association was independent of other established predictors of overall survival by multivariate analysis (hazard ratio, 2.80; 95% CI, 1.44-5.45; P < .002). Conclusions and Relevance: Neoadjuvant therapy may be associated with a significant reduction in the rate of CR-POPF. In addition, standard factors associated with CR-POPF appear to be no longer applicable following NAT. However, once CR-POPF occurs, it is associated with a significant reduction in long-term survival. Patients with CR-POPF may require closer follow-up and could benefit from additional therapy.