Faculty Bibliography

More than 2% of adults harbor a pancreatic cyst, a subset of which progresses to invasive lesions with lethal consequences. To assess the genomic landscapes of neoplastic cysts of the pancreas, we determined the exomic sequences of DNA from the neoplastic epithelium of eight surgically resected cysts of each of the major neoplastic cyst types: serous cystadenomas (SCAs), intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs), and solid pseudopapillary neoplasms (SPNs). SPNs are low-grade malignancies, and IPMNs and MCNs, but not SCAs, have the capacity to progress to cancer. We found that SCAs, IPMNs, MCNs, and SPNs contained 10 ± 4.6, 27 ± 12, 16 ± 7.6, and 2.9 ± 2.1 somatic mutations per tumor, respectively. Among the mutations identified, E3 ubiquitin ligase components were of particular note. Four of the eight SCAs contained mutations of the von Hippel-Lindau gene (VHL), a key component of the VHL ubiquitin ligase complex that has previously been associated with renal cell carcinomas, SCAs, and other neoplasms. Six of the eight IPMNs and three of the eight MCNs harbored mutations of RNF43, a gene coding for a protein with intrinsic E3 ubiquitin ligase activity that has not previously been found to be genetically altered in any human cancer. The preponderance of inactivating mutations in RNF43 unequivocally establish it as a suppressor of both IPMNs and MCNs. SPNs contained remarkably few genetic alterations but always contained mutations of CTNNB1, previously demonstrated to inhibit degradation of the encoded protein (β-catenin) by E3 ubiquitin ligases. These results highlight the essential role of ubiquitin ligases in these neoplasms and have important implications for the diagnosis and treatment of patients with cystic tumors.

OBJECTIVE:Pancreatic surgery has evolved considerably since the earliest described pancreatectomies were performed in the late 1800s. Emerging surgical techniques for pancreatic cancer have modified what was traditionally deemed unresectable disease. This review summarizes the main type of pancreatic resections used for tumor removal on the basis of location and biologic behavior. CONCLUSION/CONCLUSIONS:CT interpretation should incorporate an understanding of current surgical techniques to provide surgeons with the information necessary for patient selection and preoperative planning.

BACKGROUND:Margin status is one of the strongest prognosticators after resection of pancreatic ductal adenocarcinoma (PDAC). The clinical significance of pancreatic intraepithelial neoplasia (PanIN) at a surgical margin has not been established. METHODS:A total of 208 patients who underwent R0 resection for PDAC between 2004 and 2008 were selected. Intraoperative frozen section slides containing the final pancreatic parenchymal transection margin were evaluated for presence or absence, number, and grade of PanINs. Data were compared to clinicopathologic factors, including patient survival. RESULTS:PanIN lesions were present in margins in 107 of 208 patients (51.4%). Median number of PanINs per pancreatic resection margin was 1 (range, 1-11). A total of 72 patients had PanIN-1 (34.6%), 44 had PanIN-2 (21.1%), and 16 had PanIN-3 (7.2%) at their margin. Overall median survival was 17.9 (95% confidence interval, 14-21.9) months. Neither the presence nor absence of PanIN nor histological grade had any significant correlation with important clinicopathologic characteristics. There were no significant survival differences between patients with or without PanIN lesions at the resection margin or among patients with PanIN-3 (carcinoma in situ) versus lower PanIN grades. However, patients with R1 resection had a significantly worse outcome compared with patients without invasive cancer at a margin irrespective of the presence of PanIN (P=0.02). CONCLUSIONS:The presence of PanINs at a resection margin does not affect survival in patients who undergo R0 resection for PDAC. These results have significant clinical implications for surgeons, because no additional resection seems to be indicated when intraoperative frozen sections reveal even high-grade PanIN lesions.

INTRODUCTION/BACKGROUND:Routine palliative bypass has been advocated for palliation of patients with pancreatic adenocarcinoma who have inoperable disease discovered at the time of surgery. We examined trends in the relative use of palliative bypass over time with an emphasis on identifying changes in surgical indications, type of bypass performed, as well as perioperative outcomes associated with surgical palliation. METHODS:Between 1996 and 2010, 1,913 patients with pancreatic adenocarcinoma in the head of the pancreas were surgically explored. Data regarding preoperative symptoms, intraoperative findings, type of surgical procedure performed, as well as perioperative and long-term outcomes were collected and analyzed. RESULTS:Of the 1,913 patients, 583 (30.5%) underwent a palliative procedure. Most patients presented with jaundice (72.2%). The majority of patients were evaluated by CT scan (97.4%), which revealed a median tumor size of 3.2 cm. Most patients who underwent surgical palliation (64.5%) had a double bypass, while a minority had either gastrojejunostomy (28.2%) or hepaticojejunostomy (7.2%) alone. While the number of pancreaticoduodenectomies remained relatively stable over time, there was a temporal decrease in the utilization of palliative bypass (P < 0.001). Unanticipated locally advanced disease vs. liver/peritoneal metastasis as the indication for palliative surgery also changed over time (1996-2001: 47.8% vs. 52.2%; 2002-2007: 49.2% vs. 50.8%; 2008-2010: 17.2% vs. 82.7%) (P = 0.005). Palliative failure rates were 2.3% after hepaticojejunostomy and 3.1% after grastrojejunostomy. Patients with unsuspected metastatic disease had a worse survival compared with patients who had locally unresectable disease (median survival: 5 vs. 8 months, respectively; HR = 1.43, P = 0.001). CONCLUSION/CONCLUSIONS:Palliative bypass procedures were less frequently performed over time, probably due to a significant decrease in the rate of unanticipated advanced locoregional disease at the time of exploration. While palliative bypass was effective, survival in the setting of metastatic disease was extremely short.

OBJECTIVE:To develop and validate a risk score to predict the 30- and 90-day mortality after a pancreaticoduodenectomy or total pancreatectomy on the basis of preoperative risk factors in a high-volume program. DESIGN/METHODS:Data from a prospectively maintained institutional database were collected. In a random subset of 70% of patients (training cohort), multivariate logistic regression was used to develop a simple integer score, which was then validated in the remaining 30% of patients (validation cohort). Discrimination and calibration of the score were evaluated using area under the receiver operating characteristic curve and Hosmer-Lemeshow test, respectively. SETTING/METHODS:Tertiary referral center. PATIENTS/METHODS:The study comprised 1976 patients in a prospectively maintained institutional database who underwent pancreaticoduodenectomy or total pancreatectomy between 1998 and 2009. MAIN OUTCOME MEASURES/METHODS:The 30- and 90-day mortality. RESULTS:In the training cohort, age, male sex, preoperative serum albumin level, tumor size, total pancreatectomy, and a high Charlson index predicted 90-day mortality (area under the curve, 0.78; 95% CI, 0.71-0.85), whereas all these factors except Charlson index also predicted 30-day mortality (0.79; 0.68-0.89). On validation, the predicted and observed risks were not significantly different for 30-day (1.4% vs 1.0%; P = .62) and 90-day (3.8% vs 3.4%; P = .87) mortality. Both scores maintained good discrimination (for 30-day mortality, area under the curve, 0.74; 95% CI, 0.54-0.95; and for 90-day mortality, 0.73; 0.62-0.84). CONCLUSIONS:The risk scores accurately predicted 30- and 90-day mortality after pancreatectomy. They may help identify and counsel high-risk patients, support and calculate net benefits of therapeutic decisions, and control for selection bias in observational studies as propensity scores.

Paragangliomas are rare neuroendocrine neoplasms arising in extra-adrenal chromaffin cells of the autonomic nervous system. In rare instances, paragangliomas present around and involve the pancreas, thereby mimicking one of the more common primary pancreatic lesions. These neoplasms present considerable diagnostic difficulty not only for the clinician and radiologist but also for the pathologist. We have collected a series of 9 peripancreatic paragangliomas clinically simulating a primary pancreatic lesion. The paragangliomas were diagnosed in 4 men and 5 women with an age range of 37 to 78 years (mean, 50 y). Patients presented clinically either with diffuse epigastric and abdominal pain (7 of 9, 78%) or with an incidental mass (2 of 9, 22%) discovered on routine radiographic imaging. All patients were found to have mass lesions suspicious for a primary pancreatic neoplasm on radiographic examination. The lesions were predominantly located in the body of the pancreas (5 of 9, 56%) and ranged in size from 5.5 to 17.0 cm (mean, 10.0 cm). Five of 9 (56%) neoplasms also demonstrated cystic change. Fine-needle aspiration (FNA) was performed on 6 cases; however, the diagnostic accuracy was low, with 3 of 6 (50%) neoplasms misdiagnosed as pancreatic neuroendocrine tumor (PanNET) (n=1), spindle cell neoplasm (n=1), or pseudocyst (n=1). In addition, 2 of 8 (25%) surgically resected tumors were misdiagnosed by the referring pathologist as a PanNET. Immunohistochemistry was performed on all cases, confirming the characteristic 2-cell populations: chief cells (synaptophysin positive and chromogranin A positive) and sustentacular cells (S-100 protein positive). Follow-up information was available for all patients and ranged from 2 months to 11.6 years (mean, 2.7 y). Three of 9 (33%) patients developed metastatic disease, and 2 of these 3 died of their disease at 2.8 and 4.6 years after diagnosis. In summary, in unsuspected cases, interpretation of FNA and surgical pathology resections can be diagnostically challenging. Awareness and proper recognition of this entity, including differential diagnosis, are imperative in establishing the correct diagnosis. Further, close follow-up of these cases should be considered because of the significant risk of metastatic disease.

BACKGROUND:The role of adjuvant chemoradiation therapy for ampullary carcinoma is unknown. Previous literature suggests that certain populations with high risk factors for recurrence may benefit from adjuvant chemoradiation. We combined the experience of two institutions to better delineate which patients may benefit from adjuvant chemoradiation. METHODS:Patients who underwent curative surgery for ampullary carcinoma at the Johns Hopkins Hospital (n=290; 1992-2007) and at the Mayo Clinic (n=130; 1977-2005) were reviewed. Patients with <60 days of follow-up, metastatic disease at surgery, or insufficient pathologic data were excluded. The final combined study consisted of 186 patients (n=104 Johns Hopkins, n=82 Mayo). Most patients received 5-FU based chemoradiation with conformal radiation. Cox proportional hazards models were used for survival analysis. RESULTS:Median overall-survival was 39.9 months with 2- and 5-year survival rates of 62.4% and 39.1%. On univariate analysis, adverse prognostic factors for overall survival included T3/T4 stage disease (RR=1.86, p=0.002), node positive status (RR=3.18, p<0.001), and poor histological grade (RR=1.69, p=0.011). Patients who received adjuvant chemoradiation (n=66) vs. surgery alone (n=120) showed a higher rate of T3/T4 stage disease (57.6% vs. 30.8%, P<0.001), lymph node involvement (72.7% vs. 30.0%, P<0.001), and close or positive margins (4.6% vs. 0.0%, P=0.019). Five year survival rates among node negative and node positive patients were 58.7% and 18.4% respectively. When compared with surgery alone, use of adjuvant chemoradiation improved survival among node positive patients (mOS 32.1 vs. 15.7 mos, 5 yr OS: 27.5% vs. 5.9%; RR=0.47, P=0.004). After adjusting for adverse prognostic factors on multivariate analysis, patients treated with adjuvant chemoradiation demonstrated a significant survival benefit (RR=0.40, P<0.001). Disease relapse occurred in 37.1% of all patients, most commonly metastatic disease in the liver or peritoneum. CONCLUSIONS:Node-positive patients with resected ampullary adenocarcinoma may benefit from 5-FU based adjuvant chemoradiation. Since a significant proportion of patients develop metastatic disease, there is a need for more effective systemic treatment.

Only a minority of patients who undergo surgical resection for pancreatic ductal adenocarcinoma are cured. Since patient outcome is not reliably predicted using pathological factors (tumor stage, differentiation, and resection margin status) alone, markers of tumor behavior are needed. One candidate predictor of pancreatic cancer outcome is E-cadherin status. CDH1 is a tumor suppressor gene encoding an important cell adhesion molecule (E-cadherin). The aim of this study was to determine if, among patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma, loss of E-cadherin expression was an independent predictor of poor outcome. We examined patterns of loss of E-cadherin by immunohistochemistry in tissue microarrays of 329 surgically resected pancreatic ductal adenocarcinomas. E-cadherin expression was then correlated with outcome. Kaplan-Meier analysis and Cox proportional hazards regression modeling were used to assess the mortality risk. One hundred forty-one pancreatic adenocarcinomas (43%) had partial or complete loss of E-cadherin expression within the analyzed tissue cores. In most instances (134 cases, 41%), this loss was partial. Patients whose pancreatic adenocarcinomas had either complete loss (n=7; median survival, 5.5 months) or partial loss (n=134; 12.7 months) of E-cadherin expression had significantly worse median survival than those with uniformly intact E-cadherin expression (n=188; 18.5 months) by univariate (P=0.002) and multivariate (P=0.006) analyses. In subgroup analysis, patients with poorly differentiated cancers had a worse prognosis if their cancers had partial loss of E-cadherin expression (P=0.02). Among patients undergoing pancreaticoduodenectomy for pancreatic ductal adenocarcinoma, partial loss of tumoral E-cadherin expression is an independent predictor of poor outcome.