Faculty Bibliography

The earlier diagnosis of cancer is one of the keys to reducing cancer deaths in the future. Here we describe our efforts to develop a noninvasive blood test for the detection of pancreatic ductal adenocarcinoma. We combined blood tests for KRAS gene mutations with carefully thresholded protein biomarkers to determine whether the combination of these markers was superior to any single marker. The cohort tested included 221 patients with resectable pancreatic ductal adenocarcinomas and 182 control patients without known cancer. KRAS mutations were detected in the plasma of 66 patients (30%), and every mutation found in the plasma was identical to that subsequently found in the patient's primary tumor (100% concordance). The use of KRAS in conjunction with four thresholded protein biomarkers increased the sensitivity to 64%. Only one of the 182 plasma samples from the control cohort was positive for any of the DNA or protein biomarkers (99.5% specificity). This combinatorial approach may prove useful for the earlier detection of many cancer types.

Earlier detection is key to reducing cancer deaths. Here, we describe a blood test that can detect eight common cancer types through assessment of the levels of circulating proteins and mutations in cell-free DNA. We applied this test, called CancerSEEK, to 1005 patients with nonmetastatic, clinically detected cancers of the ovary, liver, stomach, pancreas, esophagus, colorectum, lung, or breast. CancerSEEK tests were positive in a median of 70% of the eight cancer types. The sensitivities ranged from 69 to 98% for the detection of five cancer types (ovary, liver, stomach, pancreas, and esophagus) for which there are no screening tests available for average-risk individuals. The specificity of CancerSEEK was greater than 99%: only 7 of 812 healthy controls scored positive. In addition, CancerSEEK localized the cancer to a small number of anatomic sites in a median of 83% of the patients.

OBJECTIVE:PDAC patients who undergo surgical resection and receive effective chemotherapy have the best chance of long-term survival. Unfortunately, we lack predictive biomarkers to guide optimal systemic treatment. Ex-vivo generation of PDO for pharmacotyping may serve as predictive biomarkers in PDAC. The goal of the current study was to demonstrate the clinical feasibility of a PDO-guided precision medicine framework of care. METHODS:PDO cultures were established from surgical specimens and endoscopic biopsies, expanded in Matrigel, and used for high-throughput drug testing (pharmacotyping). Efficacy of standard-of-care chemotherapeutics was assessed by measuring cell viability after drug exposure. RESULTS:A framework for rapid pharmacotyping of PDOs was established across a multi-institutional consortium of academic medical centers. Specimens obtained remotely and shipped to a central biorepository maintain viability and allowed generation of PDOs with 77% success. Early cultures maintain the clonal heterogeneity seen in PDAC with similar phenotypes (cystic-solid). Late cultures exhibit a dominant clone with a pharmacotyping profile similar to early passages. The biomass required for accurate pharmacotyping can be minimized by leveraging a high-throughput technology. Twenty-nine cultures were pharmacotyped to derive a population distribution of chemotherapeutic sensitivity at our center. Pharmacotyping rapidly-expanded PDOs was completed in a median of 48 (range 18-102) days. CONCLUSIONS:Rapid development of PDOs from patients undergoing surgery for PDAC is eminently feasible within the perioperative recovery period, enabling the potential for pharmacotyping to guide postoperative adjuvant chemotherapeutic selection. Studies validating PDOs as a promising predictive biomarker are ongoing.

OBJECTIVE:The aim of the study was to assess the association between persistent CTCs and subsequent recurrence in patients who were clinically recurrence free approximately 12 months postoperatively. BACKGROUND:Circulating tumor cells have been proposed as biomarkers to predict survival in pancreatic cancer. Some patients demonstrate persistent CTCs postoperatively which could represent minimal residual disease. METHODS:Patients from previously published prospective CLUSTER trial without clinical evidence of recurrence 12 months postoperatively and CTC testing performed 9-15 months postoperatively were included. Presence of epithelial (eCTCs) and transitional CTCs (trCTCs) was evaluated as predictor of recurrence. Kaplan-Meier curve, log-rank test, and Cox model were used for survival analysis. RESULTS:Thirty-three of 129 eligible patients (CLUSTER trial) were included. The trCTC positive and negative patients were well-balanced in clinicopathological features. Patients with trCTCs had a recurrence rate per-person-month of 10.3% compared to 3.1% in trCTCs negative patients with a median time to recurrence of 3.9 versus 27.1 months, respectively. On multivariable analysis trCTCs positivity was associated with higher risk of late recurrence (HR:4.7,95%CI:1.2-18.3, P=0.024). Fourteen (42.4%) patients recurred during the second postoperative year. 1-year postoperative trCTCs positivity was associated with a higher rate of recurrence during the second year (OR:13.1,95%CI:1.6-1953.4,P=0.028, AUC=0.72). Integrating clinicopathological features with trCTCs increased the AUC to 0.80. A majority of trCTCs positive patients (N=5, 62.5%) had multi-site recurrence, followed by local-only (N=2, 25.0%) and liver-only (N=1, 12.5%) recurrence. This was in striking contrast to trCTCs negative patients, where a majority (N=6, 66.7%) had a local-only recurrence, followed by liver-only (N=2, 22.2%) and multi-site (N=1, 11.1%) recurrence. CONCLUSION/CONCLUSIONS:In patients deemed to be clinically disease free 12 months postoperatively, trCTCs positivity is associated with higher rates of subsequent recurrence with distinct patterns of recurrence. CTCs could be used a putative biomarker to guide patient prognostication and management in pancreatic cancer.

OBJECTIVES/OBJECTIVE:The aim of the study was to assess the association of circulating tumor cells (CTCs) with survival as a biomarker in pancreatic ductal adenocarcinoma (PDAC) within the context of a delay in initiation of adjuvant therapy. BACKGROUND:Outcomes in patients with PDAC remain poor and are driven by aggressive systemic disease. While systemic therapies improve survival in resected patients, factors such as a delay in initiation of adjuvant therapy are associated with worse outcomes. CTCs have previously been shown to be predictive of survival. METHODS:A retrospective study was performed on PDAC patients enrolled in the prospective CLUSTER trial (NCT02974764) on CTC-dynamics at the Johns Hopkins Hospital. CTCs were isolated based on size (ISET; Rarecells) and counted and characterized by subtype using immunofluorescence. The preoperative and postoperative blood samples were used to identify two CTC types: epithelial CTCs (eCTCs), expressing pan-cytokeratin, and transitional CTCs (trCTCs), expressing both pan-cytokeratin and vimentin. Patients who received adjuvant therapy were compared with those who did not. A delay in receipt of adjuvant therapy was defined as initiation of therapy ≥8 weeks after surgical resection. Clinicopathological features, CTCs characteristics, and outcomes were analyzed. RESULTS:Of 101 patients included in the study, 43 (42.5%) experienced a delay in initiation and 20 (19.8%) did not receive adjuvant therapy. On multivariable analysis, presence of transitional CTCs (trCTCs, P=0.002) and absence of adjuvant therapy (P=0.032) were associated with worse recurrence-free survival (RFS). Postoperative trCTC were associated with poorer RFS, both in patients with a delay in initiation (12.4 vs. 17.9 mo, P=0.004) or no administration of adjuvant chemotherapy (3.4 vs. NR, P=0.016). However, it was not associated with RFS in patients with timely initiation of adjuvant chemotherapy (P=0.293). CONCLUSION/CONCLUSIONS:Postoperative trCTCs positivity is associated with poorer RFS only in patients who either experience a delay in initiation or no receipt of adjuvant therapy. This study suggests that a delay in initiation of adjuvant therapy could potentially provide residual systemic disease (trCTCs) a window of opportunity to recover from the surgical insult. Future studies are required to validate these findings and explore the underlying mechanisms involved.

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/BACKGROUND: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 12 months (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.

OBJECTIVE:This study seeks to evaluate the efficacy of negative pressure wound therapy for surgical-site infection (SSI) after open pancreaticoduodenectomy. BACKGROUND:Despite improvement in infection control, SSIs remain a common cause of morbidity after abdominal surgery. SSI has been associated with an increased risk of reoperation, prolonged hospitalization, readmission, and higher costs. Recent retrospective studies have suggested that the use of negative pressure wound therapy can potentially prevent this complication. METHODS:We conducted a single-center randomized, controlled trial evaluating surgical incision closure during pancreaticoduodenectomy using negative pressure wound therapy in patients at high risk for SSI. We randomly assigned patients to receive negative pressure wound therapy or a standard wound closure. The primary end point of the study was the occurrence of a postoperative SSI. We evaluated the economic impact of the intervention. RESULTS:From January 2017 through February 2018, we randomized 123 patients at the time of closure of the surgical incision. SSI occurred in 9.7% (6/62) of patients in the negative pressure wound therapy group and in 31.1% (19/61) of patients in the standard closure group (relative risk = 0.31; 95% confidence interval, 0.13-0.73; P = 0.003). This corresponded to a relative risk reduction of 68.8%. SSIs were found to independently increase the cost of hospitalization by 23.8%. CONCLUSIONS:The use of negative pressure wound therapy resulted in a significantly lower risk of SSIs. Incorporating this intervention in surgical practice can help reduce a complication that significantly increases patient harm and healthcare costs.

PURPOSE:ctDNA assay in a Clinical Laboratory Improvement Amendments (CLIA) and College of American Pathology-certified clinical laboratory. EXPERIMENTAL DESIGN:mutations (G12D, G12V, G12R, and Q61H) in liquid biopsies. For clinical validation, 290 preoperative and longitudinal postoperative plasma samples were collected from 59 patients with PDAC. The utility of ctDNA status to predict PDAC recurrence during follow-up was assessed. RESULTS:= 0.011). CONCLUSIONS:ctDNA in a CLIA laboratory setting can be used to predict recurrence and survival in patients with PDAC.

PURPOSE/OBJECTIVE:Accurate staging of disease is vital in determining appropriate care for patients with pancreatic ductal adenocarcinoma (PDAC). It has been shown that the quality of scans and the experience of a radiologist can impact computed tomography (CT) based assessment of disease. The aim of the current study was to evaluate the impact of the rereading of outside hospital (OH) CT by an expert radiologist and a repeat pancreatic protocol CT (PPCT) on staging of disease. METHODS:Patients evaluated at the our institute's pancreatic multidisciplinary clinic (2006 to 2014) with OH scan and repeat PPCT performed within 30 days were included. In-house radiologists staged disease using OH scans and repeat PPCT, and factors associated with misstaging were determined. RESULTS:The study included 100 patients, with a median time between OH scan and PPCT of 19 days (IQR: 13-23 days.) Stage migration was mostly accounted for by upstaging of disease (58.8 % to 83.3 %) in all comparison groups. When OH scans were rereviewed, 21.5 % of the misstaging was due to missed metastases, however, when rereads were compared to the PPCT, occult metastases accounted for the majority of misstaged patients (62.5 %). Potential factors associated with misstaging were primarily related to imaging technique. CONCLUSION/CONCLUSIONS:A repeat PPCT results in increased detection of metastatic disease that rereviews of OH scans may otherwise miss. Accessible insurance coverage for repeat PPCT imaging even within 30 days of an OH scan could help optimize delivery of care and alleviate burdens associated with misstaging.