Percutaneous biopsy of periarterial soft tissue cuffs in the diagnosis of pancreatic carcinoma

Highly Sensitive Exosome Detection for Early Diagnosis of Pancreatic Cancer Using Immunoassay Based on Hierarchical Surface-Enhanced Raman Scattering Substrate

Exosomes have emerged as potential biomarkers for pancreatic cancer (PaC). However, it is still challenging to get quantitative detection of exosomes with the specific surface receptors. In this study, a highly sensitive detection system is first constructed for the direct quantitation of specific exosomes in real samples using hierarchical surface-enhanced Raman scattering substrate (H-SERS substrate) and rapid enrichment strategy magnetic beads @ exosomes @ SERS detection probes (MEDP). It is found that the detection system (MEDP @ H-SERS substrate) could provide a 3.5 times higher SERS intensity compared with MEDP sandwich immunocomplex only. Moreover, LRG1-positive exosomes (LRG1-Exos) and GPC1-positive exosomes (GPC1-Exos) are chosen to distinguish PaC through exosome proteomics and database screening. The lower limit of detection (LOD) is 15 particles µL-1 using the MEDP @ H-SERS substrate. Significantly, the detection in clinical samples shows that the innovative combination of LRG1-Exos and GPC1-Exos could improve the diagnostic efficiency of PaC, with an area under the operating characteristic curve (AUC) of 0.95. Even for the early-stage PaC, the diagnostic accuracy is still high (AUC = 0.95). Collectively, the findings indicate that the MEDP @ H-SERS substrate has great potential for the early diagnosis of PaC.

The Utility of EUS-FNA to Determine Surgical Candidacy in Patients with Pancreatic Cancer after Neoadjuvant Therapy

BACKGROUND

In patients with borderline resectable pancreatic cancer (BRPC) or locally advanced pancreatic cancer (LAPC) who undergo neoadjuvant therapy, CT imaging is the standard of care for restaging. However, differentiating residual tumor from post-treatment inflammation with CT is unreliable. The diagnosis of periarterial soft tissue cuffing (PSTC) near major vessels is key to guiding resectability. The goal of this study was to assess the utility of EUS-FNA in determining the etiology of PSTC in BRPC or LAPC after neoadjuvant treatment.

METHODS

We performed a retrospective analysis of patients referred for EUS-FNA of PSTC following downstaging therapy for LAPC or BRPC at our tertiary medical center. Negative EUS-FNA cytology results were compared with surgical pathology after resection. Patients with positive EUS-FNA cytology results were either followed clinically or results were compared to surgical pathology if surgery was attempted despite the positive cytology.

RESULTS

Fourteen patients were included in the study of whom four had positive cytology. Two of these patients had progression of disease, and two had attempted resection with positive surgical pathology (100% true positives). All ten patients with negative cytology underwent attempted surgical resection. Nine patients (90%) achieved negative margins, and one patient (10%) had a positive surgical margin. The sensitivity, specificity, and accuracy of EUS-FNA for determining resectability were 80%, 100%, and 92.9%, respectively.

CONCLUSIONS

In this series of patients with BRPC or LAPC and persistent PSTC after downstaging neoadjuvant treatment, EUS-FNA accurately determined surgical resectability and should be considered as part of the evaluation of such patients.

Safety, Diagnostic Accuracy, and Effects of Endoscopic Ultrasound Fine-Needle Aspiration on Detection of Extravascular Migratory Metastases

BACKGROUND & AIMS

Tumor cells can migrate via diminutive perivascular cuffing to distant sites along blood vessels to form extravascular migratory metastases (EVMM). These metastases usually are identified during surgery or autopsies. We aimed to evaluate the feasibility and safety of endoscopic ultrasound fine-needle aspiration (EUS-FNA) of perivascular soft-tissue cuffs to detect EVMM. We compared findings from EUS with those from noninvasive cross-sectional imaging (reference standard) of patients who underwent EUS-FNA to assess suspected EVMM and studied the effects on pancreatic tumor staging and determination of resectability.

METHODS

We performed a retrospective analysis of 253 patients (mean age, 62 ± 12 y) who underwent EUS-FNA of 267 vessels for evaluation of suspected EVMM, from April 2001 through May 2018. EUS findings were compared with those from computed tomography (CT) and magnetic resonance imaging (MRI) as the reference standard. Lesions were considered to be malignant based on cytology analysis of FNA samples, histology analyses of surgical or biopsy specimens, or vascular abnormalities detected by CT or MRI that clearly indicate EVMM.

RESULTS

Thirty patients were found to have benign lesions. The remaining 223 patients who had malignancies (166 with pancreatic ductal adenocarcinomas [PDACs]), underwent further analyses. A median of 4 FNAs (range, 1-20 FNAs) were obtained from 4-mm perivascular soft-tissue cuffs (range, 2-20 mm). FNA and cytology analysis showed malignant cells in 163 vessels (69.4%) from 157 patients (70.4%). CT or MRI did not detect EVMM in 44 patients (28%) with malignancies, including 24 patients (24%) with newly diagnosed PDAC. Detection of EVMM by EUS-FNA resulted in upstaging of 15 patients and conversion of 14 patients with PDAC from resectable (based on CT or MRI) to unresectable. No adverse events were reported during a follow-up period of 3.9 months (range, 0-117 mo).

CONCLUSIONS

EUS-FNA and cytologic analysis of perivascular soft-tissue cuffs can detect EVMM that were not found in 28% of patients by CT or MRI. Detection of EVMM affects tumor staging and determination of tumor resectability.

Utility of endoscopic ultrasound (EUS)-guided fine-needle aspiration for peri-arterial soft tissue cuffs without identifiable pancreas mass on CT and EUS: a prospective comparative study

Pancreatic cancer may present as a peri-arterial soft tissue cuff (PSTC) around the superior mesenteric artery or celiac axis without an identifiable pancreatic mass. We evaluated the diagnostic yield of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in patients with a PSTC without definite pancreas involvement and those with a typical pancreatic mass. The patients who underwent EUS-FNA of a PSTC without pancreatic involvement were prospectively enrolled. The patients who underwent EUS-FNA for a pancreatic mass were recruited as a control group. A total of 224 patients underwent 247 EUS-FNAs. Among the 13 patients with a PSTC, 11 were positive for malignancy as determined by EUS-FNA, with 5 diagnosed after the first session and 6 after the second session. The diagnostic yield of PSTCs by EUS-FNA was significantly lower than that for typical pancreatic masses (65% vs. 87%, p = 0.02). An on-site cytopathologist and repeated EUS-FNA are recommended to improve the diagnostic accuracy of this disease entity.