Extracellular vesicle analysis of plasma allows differential diagnosis of atypical pancreatic serous cystadenoma.

Increased use of cross-sectional imaging has resulted in frequent detection of incidental cystic pancreatic lesions. Serous cystadenomas (SCAs) are benign cysts that do not require surgical intervention unless symptomatic. Unfortunately, up to half of SCAs do not have typical imaging findings ("atypical SCAs"), overlap with potentially malignant precursor lesions, and thus pose a diagnostic challenge. We tested whether the analysis of circulating extracellular vesicle (EV) biomarkers using a digital EV screening technology (DEST) could enhance the discrimination of cystic pancreatic lesions and avoid unnecessary surgical intervention in these atypical SCAs. Analysis of 25 different protein biomarkers in plasma EV from 68 patients identified a putative biomarker signature of Das-1, Vimentin, Chromogranin A, and CAIX with high discriminatory power (AUC of 0.99). Analysis of plasma EV for multiplexed markers may thus be helpful in clinical decision-making.

Single-EV analysis (sEVA) of mutated proteins allows detection of stage 1 pancreatic cancer.

Tumor cell-derived extracellular vesicles (EVs) are being explored as circulating biomarkers, but it is unclear whether bulk measurements will allow early cancer detection. We hypothesized that a single-EV analysis (sEVA) technique could potentially improve diagnostic accuracy. Using pancreatic cancer (PDAC), we analyzed the composition of putative cancer markers in 11 model lines. In parental PDAC cells positive for KRASmut and/or P53mut proteins, only ~40% of EVs were also positive. In a blinded study involving 16 patients with surgically proven stage 1 PDAC, KRASmut and P53mut protein was detectable at much lower levels, generally in <0.1% of vesicles. These vesicles were detectable by the new sEVA approach in 15 of the 16 patients. Using a modeling approach, we estimate that the current PDAC detection limit is at ~0.1-cm3 tumor volume, below clinical imaging capabilities. These findings establish the potential for sEVA for early cancer detection.

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.

Staging Laparoscopy Not Only Saves Patients an Incision, But May Also Help Them Live Longer.

BACKGROUND: Approximately 20-40% of patients with "resectable" pancreatic adenocarcinoma (PDAC) by imaging criteria have metastatic disease on exploration. Our aim was to assess the potential impact of staging laparoscopy versus upfront laparotomy in "resectable" patients found to have metastatic PDAC. METHODS: Clinicopathologic data was retrospectively collected for all patients with PDAC undergoing an operation with curative intent between 2001-2015 at a single institution. RESULTS: Of the 1001 patients undergoing surgical evaluation, 151 had unsuspected metastatic PDAC. Staging laparoscopy was performed in 59% (89/151) of patients, while 41% (62/151) underwent an exploratory laparotomy with or without prophylactic bypass. There were no differences in patient demographics and preoperative CA 19-9 levels between the staging laparoscopy and exploratory laparotomy groups. However, staging laparoscopy was more often performed for pancreatic body/tail lesions (85% vs 60% for pancreatic head lesions, p < 0.001). Patients who only underwent laparoscopy started palliative chemotherapy more quickly (17.9 days vs 39.9 days in the laparotomy group, p < 0.001). There was no difference in the 30 day or lifetime incidence of postoperative cholangitis, gastric outlet obstruction, or biliary stent placement between groups. The median overall survival for the staging laparoscopy group (11.4 months) was significantly longer than the laparotomy group (8.3 months, p < 0.001). In a cox regression analysis adjusting for clinicopathologic variables, staging laparoscopy was associated with significantly improved overall survival when compared to the laparotomy group (HR 0.53, 95% C.I. 0.34-0.82, p = 0.005). CONCLUSION: For patients diagnosed with metastatic PDAC at the time of surgical exploration, staging laparoscopy was associated with a shorter time to chemotherapy and improved overall survival when compared to those explored without laparoscopy.

Multiparametric plasma EV profiling facilitates diagnosis of pancreatic malignancy.

Pancreatic ductal adenocarcinoma (PDAC) is usually detected late in the disease process. Clinical workup through imaging and tissue biopsies is often complex and expensive due to a paucity of reliable biomarkers. We used an advanced multiplexed plasmonic assay to analyze circulating tumor-derived extracellular vesicles (tEVs) in more than 100 clinical populations. Using EV-based protein marker profiling, we identified a signature of five markers (PDACEV signature) for PDAC detection. In our prospective cohort, the accuracy for the PDACEV signature was 84% [95% confidence interval (CI), 69 to 93%] but only 63 to 72% for single-marker screening. One of the best markers, GPC1 alone, had a sensitivity of 82% (CI, 60 to 95%) and a specificity of 52% (CI, 30 to 74%), whereas the PDACEV signature showed a sensitivity of 86% (CI, 65 to 97%) and a specificity of 81% (CI, 58 to 95%). The PDACEV signature of tEVs offered higher sensitivity, specificity, and accuracy than the existing serum marker (CA 19-9) or single-tEV marker analyses. This approach should improve the diagnosis of pancreatic cancer.

Prospective evaluation of reader performance on MDCT in characterization of cystic pancreatic lesions and prediction of cyst biologic aggressiveness.

OBJECTIVE: Our objective was to evaluate the accuracy of MDCT features of pancreatic cystic lesions in cyst characterization and in predicting cyst biologic aggressiveness. SUBJECTS AND METHODS: In this prospective study, 114 patients (40 men and 74 women; age range, 23-89 years) with 130 cystic lesions (size range, 31-160 mm) in the pancreas underwent contrast-enhanced dual-phase (n = 92) and portal phase (n = 22) examinations with 16- or 64-MDCT scanners. Using defined morphologic features of cystic lesions on MDCT, two readers performed blinded evaluations for cystic characterization and predicting biologic aggressiveness (invasive lesions, carcinoma in situ, and moderate grade dysplasias) before pancreatic surgery. Receiver operating characteristic analysis was performed to assess the accuracy of MDCT using pathologic evaluation of the surgical specimen as a reference standard. RESULTS: On the basis of MDCT features, the radiologic accuracy (reader 1 and reader 2) for stratifying lesions into mucinous and nonmucinous subtypes was 85% and 82% and for recognizing cysts with aggressive biology was 86% and 85%, respectively. Predictive values of MDCT were superior for lesions > 30 mm and nonmucinous lesions. Features favoring aggressive biology were main pancreatic duct dilation > 10 mm (p < 0.0001), biliary obstruction (p=0.01), mural nodule (p < 0.0001), main-duct intraductal papillary mucinous neoplasm (p < 0.0001), and advanced age (p = 0.0001). Sensitivity of detecting morphologic features was higher with the dual-phase pancreatic protocol CT. CONCLUSION: Morphologic features of pancreatic cystic lesions on MDCT allow reliable characterization into mucinous and nonmucinous subtypes and enable prediction of biologic aggressiveness.

Long-term results of intraoperative electron beam irradiation (IOERT) for patients with unresectable pancreatic cancer.

SUMMARY BACKGROUND DATA: To analyze the effects of a treatment program of intraoperative electron beam radiation therapy (IOERT) and external beam radiation therapy and chemotherapy on the outcome of patients with unresectable or locally advanced pancreatic cancer. METHODS: From 1978 to 2001, 150 patients with unresectable and nonmetastatic pancreatic cancer received IOERT combined with external beam radiation therapy and 5-fluorouracil-based chemotherapy for definitive treatment. RESULTS: The 1-, 2-, and 3-year actuarial survival rates of all 150 patients were 54%, 15%, and 7%, respectively. Median and mean survival rates were 13 and 17 months, respectively. Long-term survival has been observed in 8 patients. Five patients have survived beyond 5 years and 3 more between 3 and 4 years. There was a statistically significant correlation of survival to the diameter of treatment applicator (a surrogate for tumor size) used during IOERT. For 26 patients treated with a small-diameter applicator (5 cm or 6 cm), the 2- and 3-year actuarial survival rates were 27% and 17%, respectively. In contrast, none of the 11 patients treated with a 9-cm-diameter applicator survived beyond 18 months. Intermediate survival rates were seen for patients treated with a 7- or 8-cm-diameter applicator. Operative mortality was 0.6%, and postoperative and late complications were 20% and 15%, respectively. CONCLUSIONS: A treatment strategy employing IOERT has resulted in long-term survival in 8 of 150 patients with unresectable pancreatic cancer. Survival benefit was limited to patients with small tumors. Enrollment of selected patients with small tumors into innovative protocols employing this treatment approach is appropriate.

A rare case of gonadal agenesis with paramesonephric derivatives in a patient with a normal female karyotype.

OBJECTIVE: To report a rare case of gonadal agenesis with rudimentary paramesonephric ducts derivatives in a female with a 46,XX normal karyotype. DESIGN: Case study. SETTING: National Institute of Health. PATIENT(S): An 18-year-old female with primary amenorrhea and lack of secondary sexual development. INTERVENTION(S): Clinical, gynecological, endocrine, and genetic evaluation. Laboratory studies conducted included measurement of pituitary, ovary, and thyroid hormones; analyses of G-banded chromosomes in peripheral blood and fibroblast cultures; search for genomic Y-chromosome DNA by fluorescence in situ hybridization and molecular biology techniques; X-ray, ultrasonography, echocardiographic and laparoscopic studies for the assessment of bone age, and genitourinary and other associated malformations. MAIN OUTCOME MEASURE(S): Clinical, hormonal, anatomical, and genetic characteristics of the patient. RESULT(S): The studies performed confirmed a prepubertal female with hypergonadotrophic hypogonadism, bilateral gonadal agenesis, a rudimentary uterus and fallopian tubes, a normal vagina, kidney, and urinary tract structures, and a 46,XX normal karyotype. The search for centromeric Y-chromosome DNA and SRY and ZFY genes was negative. CONCLUSION(S): A primary deficiency confined to the gonadal blastema and the nearby coelomic epithelium is proposed as an alternative embryologic mechanism to explain the occurrence of this singular sexual developmental defect.

Diagnosis of pancreatic cystic neoplasms: a report of the cooperative pancreatic cyst study.

BACKGROUND & AIMS: Cysts of the pancreas display a wide spectrum of histology, including inflammatory (pseudocysts), benign (serous), premalignant (mucinous), and malignant (mucinous) lesions. Endoscopic ultrasonography (EUS) may offer a diagnostic tool through the combination of imaging and guided, fine-needle aspiration (FNA). The purpose of this investigation was to determine the most accurate test for differentiating mucinous from nonmucinous cystic lesions. METHODS: The results of EUS imaging, cyst fluid cytology, and cyst fluid tumor markers (CEA, CA 72-4, CA 125, CA 19-9, and CA 15-3) were prospectively collected and compared in a multicenter study using histology as the final diagnostic standard. RESULTS: Three hundred forty-one (341) patients underwent EUS and FNA of a pancreatic cystic lesion; 112 of these patients underwent surgical resection, providing a histologic diagnosis of the cystic lesion (68 mucinous, 7 serous, 27 inflammatory, 5 endocrine, and 5 other). Receiver operator curve analysis of the tumor markers demonstrated that cyst fluid CEA (optimal cutoff of 192 ng/mL) demonstrated the greatest area under the curve (0.79) for differentiating mucinous vs. nonmucinous cystic lesions. The accuracy of CEA (88 of 111, 79%) was significantly greater than the accuracy of EUS morphology (57 of 112, 51%) or cytology (64 of 109, 59%) (P < 0.05). There was no combination of tests that provided greater accuracy than CEA alone (P < 0.0001). CONCLUSIONS: Of tested markers, cyst fluid CEA is the most accurate test available for the diagnosis of mucinous cystic lesions of the pancreas.