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.

CEL-HYB is a hybrid allele that arose from a crossover between the 3' end of the Carboxyl ester lipase (CEL) gene and the nearby CEL pseudogene (CELP) and was recently identified as a risk factor for chronic pancreatitis. Since chronic pancreatitis is a risk factor for the development of pancreatic cancer, we compared the prevalence of the CEL-HYB allele in patients with pancreatic ductal adenocarcinoma to spousal controls and disease controls. The CEL-HYB allele was detected using Sanger and next generation sequencing. There was no significant difference in the prevalence of the CEL-HYB allele between cases with pancreatic ductal adenocarcinoma compared to controls; 2.6% (22/850) vs. 1.8% (18/976) (p=0.35). CEL-HYB carriers were not more likely to report a history of pancreatitis. Patients with pancreatic cancer are not more likely than controls to be carriers of the CEL-HYB allele.

BACKGROUND:Sarcomatoid carcinoma of the pancreas (SCP) is a rare histologic subtype of undifferentiated pancreatic carcinoma. Historically, this has been associated with a worse overall prognosis than adenocarcinoma. However, the clinical course and surgical outcomes of SCP remain poorly characterized owing to its rarity. METHODS:A single-institution, prospectively maintained database was queried for patients who underwent pancreatic resection with a final diagnosis of SCP. We describe their histology, clinicopathologic features, and perioperative outcomes. Survival data are highlighted, and common traits of long-term survivors are examined. RESULTS:Over a 25-year period, 7009 patents underwent pancreatic resection at our institution. Eight (0.11%) were diagnosed with SCP on final histopathology. R0 resection was achieved in six patients (75%). Four patients had early recurrence leading to death (<3 months). Two (25%) experienced long-term survival (>5 years), with the longest surviving nearly 16 years despite the presence of lymph node metastasis. There were no deaths attributed to perioperative complications. Both long-term survivors had disease in the body/tail of the pancreas and received adjuvant radiotherapy. One also received adjuvant gemcitabine-based chemotherapy. CONCLUSIONS:SCP is a rarely appreciated subset of pancreatic malignancy that does not necessarily portend to a uniformly dismal prognosis. Although some have rapid recurrence and an early demise, long-term survival may be possible. Future studies are needed to better define the cohort with potential for long-term survival so that aggressive therapies may be tailored appropriately in this patient subset.

OBJECTIVE:The aim of this study was to evaluate and validate the proposed 8th edition American Joint Committee on Cancer (AJCC) system for T and N staging of pancreatic adenocarcinoma. SUMMARY OF BACKGROUND DATA:Investigators have questioned the clinical relevance and reproducibility of previous AJCC staging for pancreatic adenocarcinoma. METHODS:Prospective databases at Memorial Sloan Kettering (MSK), Massachusetts General Hospital (MGH), and Johns Hopkins Hospital (JHH) were queried for patients who had undergone resection for pancreatic adenocarcinoma. Patients who underwent a margin-negative (R0) resection, and who had previously undergone pathologic review, were included. Patients were staged according to 7th edition AJCC criteria, as well as the proposed 8th edition system that includes different definitions of tumor size (T) and nodal status (N). The dataset was randomly split into training and test sets. RESULTS:Two thousand three hundred eighteen patients were identified who met inclusion criteria. Recursive partitioning on the training set (n = 1551) identified statistically appropriate cutoffs for tumor size (<2.2 cm, ≥4.8 cm,) and nodal status (no positive nodes, 1 to 3 positive nodes, ≥4 positive nodes) that supported the proposed 8th edition changes. Median survival in patients staged as T3, N0 by the 7th edition definitions was different between institutions (median Center 1, 24 mo; Center 2, 37 mo; Center 3, 29 mo; P = 0.054). This difference was not observed when patients were staged as T3, N0 by 8th edition criteria. Stage, and stage-specific outcome (7th edition), on the test set revealed a predominance of patients (68%) within the IIB subgroup, and a concordance probability estimate (CPE) of 0.57 for stage-specific survival. When assessed with 8th edition criteria, no stage subgroup had a majority of patients, and the CPE was 0.58. CONCLUSIONS:The proposed 8th edition changes for T and N classification were statistically valid and may allow a more reproducible system of T staging. This system also stratifies patients more evenly across stages without sacrificing prognostic accuracy.

OBJECTIVE:This multicenter study sought to evaluate the accuracy of the American College of Surgeons National Surgical Quality Improvement Program's (ACS-NSQIP) surgical risk calculator for predicting outcomes after pancreatoduodenectomy (PD) and to determine whether incorporating other factors improves its predictive capacity. BACKGROUND:The ACS-NSQIP surgical risk calculator has been proposed as a decision-support tool to predict complication risk after various operations. Although it considers 21 preoperative factors, it does not include procedure-specific variables, which have demonstrated a strong predictive capacity for the most common and morbid complication after PD - clinically relevant pancreatic fistula (CR-POPF). The validated Fistula Risk Score (FRS) intraoperatively predicts the occurrence of CR-POPF and serious complications after PD. METHODS:This study of 1480 PDs involved 47 surgeons at 17 high-volume institutions. Patient complication risk was calculated using both the universal calculator and a procedure-specific model that incorporated the FRS and surgeon/institutional factors. The performance of each model was compared using the c-statistic and Brier score. RESULTS:The FRS was significantly associated with 30-day mortality, 90-day mortality, serious complications, and reoperation (all P < 0.0001). The procedure-specific model outperformed the universal calculator for 30-day mortality (c-statistic: 0.79 vs 0.68; Brier score: 0.020 vs 0.021), 90-day mortality, serious complications, and reoperation. Neither surgeon experience nor institutional volume significantly predicted mortality; however, surgeons with a career PD volume >450 were less likely to have serious complications (P < 0.001) or perform reoperations (P < 0.001). CONCLUSIONS:Procedure-specific complication risk influences outcomes after pancreatoduodenectomy; therefore, risk adjustment for performance assessment and comparative research should consider these preoperative and intraoperative factors along with conventional ACS-NSQIP preoperative variables.

OBJECTIVE:Our objective was to develop an approach for selecting combinatorial markers of pathology from diverse clinical data types. We demonstrate this approach on the problem of pancreatic cyst classification. MATERIALS AND METHODS:We analyzed 1026 patients with surgically resected pancreatic cysts, comprising 584 intraductal papillary mucinous neoplasms, 332 serous cystadenomas, 78 mucinous cystic neoplasms, and 42 solid-pseudopapillary neoplasms. To derive optimal markers for cyst classification from the preoperative clinical and radiological data, we developed a statistical approach for combining any number of categorical, dichotomous, or continuous-valued clinical parameters into individual predictors of pathology. The approach is unbiased and statistically rigorous. Millions of feature combinations were tested using 10-fold cross-validation, and the most informative features were validated in an independent cohort of 130 patients with surgically resected pancreatic cysts. RESULTS:We identified combinatorial clinical markers that classified serous cystadenomas with 95% sensitivity and 83% specificity; solid-pseudopapillary neoplasms with 89% sensitivity and 86% specificity; mucinous cystic neoplasms with 91% sensitivity and 83% specificity; and intraductal papillary mucinous neoplasms with 94% sensitivity and 90% specificity. No individual features were as accurate as the combination markers. We further validated these combinatorial markers on an independent cohort of 130 pancreatic cysts, and achieved high and well-balanced accuracies. Overall sensitivity and specificity for identifying patients requiring surgical resection was 84% and 81%, respectively. CONCLUSIONS:Our approach identified combinatorial markers for pancreatic cyst classification that had improved performance relative to the individual features they comprise. In principle, this approach can be applied to any clinical dataset comprising dichotomous, categorical, and continuous-valued parameters.

OBJECTIVE:The aim of this study was to characterize patterns of local progression following resection for pancreatic intraductal papillary mucinous neoplasms (IPMN) using targeted next-generation sequencing (NGS). BACKGROUND:Progression of neoplastic disease in the remnant pancreas following resection of IPMN may include development of a new IPMN or ductal adenocarcinoma (PDAC). However, it is not clear whether this progression represents recurrence of the same neoplasm or an independent second neoplasm. METHODS:Targeted-NGS on genes commonly mutated in IPMN and PDAC was performed on tumors from (1) 13 patients who developed disease progression in the remnant pancreas following resection of IPMN; and (2) 10 patients who underwent a resection for PDAC and had a concomitant IPMN. Mutations in the tumors were compared in order to determine the relationship between neoplasms. In parallel, clinical and pathological characteristics of 260 patients who underwent resection of noninvasive IPMN were reviewed to identify risk factors associated with local progression. RESULTS:We identified 3 mechanisms underlying local progression in the remnant pancreas: (1) residual microscopic disease at the resection margin, (2) intraparenchymal spread of neoplastic cells, leading to an anatomically separate but genetically related recurrence, and (3) multifocal disease with genetically distinct lesions. Analysis of the 260 patients with noninvasive IPMNs showed that family history of pancreatic cancer (P = 0.027) and high-grade dysplasia (HGD) (P = 0.003) were independent risk factors for the development of an IPMN with HGD or an invasive carcinoma in the remnant pancreas. CONCLUSIONS:Using NGS, we identify distinct mechanisms for development of metachronous or synchronous neoplasms in patients with IPMN. Patients with a primary IPMN with HGD or with positive family history are at an increased risk to develop subsequent high-risk neoplasms in the remnant pancreas.

Purpose Deleterious germline mutations contribute to pancreatic cancer susceptibility and are well documented in families in which multiple members have had pancreatic cancer. Methods To define the prevalence of these germline mutations in patients with apparently sporadic pancreatic cancer, we sequenced 32 genes, including known pancreatic cancer susceptibility genes, in DNA prepared from normal tissue obtained from 854 patients with pancreatic ductal adenocarcinoma, 288 patients with other pancreatic and periampullary neoplasms, and 51 patients with non-neoplastic diseases who underwent pancreatic resection at Johns Hopkins Hospital between 2000 and 2015. Results Thirty-three (3.9%; 95% CI, 3.0% to 5.8%) of 854 patients with pancreatic cancer had a deleterious germline mutation, 31 (3.5%) of which affected known familial pancreatic cancer susceptibility genes: BRCA2 (12 patients), ATM (10 patients), BRCA1 (3 patients), PALB2 (2 patients), MLH1 (2 patients), CDKN2A (1 patient), and TP53 (1 patient). Patients with these germline mutations were younger than those without (mean ± SD, 60.8 ± 10.6 v 65.1 ± 10.5 years; P = .03). Deleterious germline mutations were also found in BUB1B (1) and BUB3 (1). Only three of these 33 patients had reported a family history of pancreatic cancer, and most did not have a cancer family history to suggest an inherited cancer syndrome. Five (1.7%) of 288 patients with other periampullary neoplasms also had a deleterious germline mutation. Conclusion Germline mutations in pancreatic cancer susceptibility genes are commonly identified in patients with pancreatic cancer without a significant family history of cancer. These deleterious pancreatic cancer susceptibility gene mutations, some of which are therapeutically targetable, will be missed if current family history guidelines are the main criteria used to determine the appropriateness of gene testing.