Faculty Bibliography

PURPOSE/OBJECTIVE:The purpose of this study is to identify factors predictive of early mortality following palliative bypass in patients with previously unsuspected advanced pancreatic adenocarcinoma to provide a basis for the selection of appropriate therapies. METHODS:All patients with pancreatic adenocarcinoma who underwent a bypass procedure at our institution between 9/30/1994 and 1/31/2006 were reviewed. Patients with peri-operative mortality were excluded from the analysis. Univariate analysis was performed on peri-operative data to identify factors associated with early mortality (death within 6 months of surgery). Patients having multiple risk factors were assigned an overall prognostic score based on the sum of these factors. RESULTS:Of the 397 patients with pancreatic adenocarcinoma analyzed, four factors were found to predict early mortality following palliative bypass: Presence of distant metastatic disease (HR 2.59, P < 0.0001), poor tumor differentiation (HR 1.71, P = 0.009), severe pre-operative nausea and vomiting (HR 1.48, P = 0.013), and lack of previous placement of a biliary stent (HR 1.36, P = 0.048). Patients with a prognostic score of 0 were significantly more likely to survive past 6 months than patients with a prognostic score of 1 (HR 2.71, P < 0.0001), 2 (HR 3.70, P < 0.0001), or ≥3 (HR 5.63, P < 0.0001). CONCLUSIONS:In a cohort of patients undergoing a palliative bypass procedure, specific peri-operative factors can be used to identify patients who are at risk of early mortality. These factors may be helpful in selecting appropriate interventions for this group of patients.

Approximately 45% of sporadic well-differentiated pancreatic neuroendocrine tumors harbor mutations in either ATRX (alpha thalassemia/mental retardation X-linked) or DAXX (death domain-associated protein). These novel tumor suppressor genes encode nuclear proteins that interact with one another and function in chromatin remodeling at telomeric and peri-centromeric regions. Mutations in these genes are associated with loss of their protein expression and correlate with the alternative lengthening of telomeres phenotype. Patients with multiple endocrine neoplasia-1 (MEN-1) syndrome, genetically defined by a germ line mutation in the MEN1 gene, are predisposed to developing pancreatic neuroendocrine tumors and thus represent a unique model for studying the timing of ATRX and DAXX inactivation in pancreatic neuroendocrine tumor development. We characterized ATRX and DAXX protein expression by immunohistochemistry and telomere status by telomere-specific fluorescence in situ hybridization in 109 well-differentiated pancreatic neuroendocrine lesions from 28 MEN-1 syndrome patients. The study consisted of 47 neuroendocrine microadenomas (<0.5 cm), 50 pancreatic neuroendocrine tumors (≥0.5 cm), and 12 pancreatic neuroendocrine tumor lymph node metastases. Expression of ATRX and DAXX was intact in all 47 microadenomas, and none showed the alternative lengthening of telomeres phenotype. ATRX and/or DAXX expression was lost in 3 of 50 (6%) pancreatic neuroendocrine tumors. In all three of these, tumor size was ≥3 cm, and loss of ATRX and/or DAXX expression correlated with the alternative lengthening of telomeres phenotype. Concurrent lymph node metastases were present for two of the three tumors, and each metastasis displayed the same changes as the primary tumor. These findings establish the existence of ATRX and DAXX defects and the alternative lengthening of telomeres phenotype in pancreatic neuroendocrine tumors in the context of MEN-1 syndrome. The observation that ATRX and DAXX defects and the alternative lengthening of telomeres phenotype occurred only in pancreatic neuroendocrine tumors measuring ≥3 cm and their lymph node metastases suggests that these changes are late events in pancreatic neuroendocrine tumor development.

BACKGROUND:Duodenal adenocarcinoma is a rare cancer usually studied as a group with periampullary or small bowel adenocarcinoma; therefore, its natural history is poorly understood. METHODS:Patients with duodenal adenocarcinoma were identified from a single-institution pancreaticoduodenectomy database. Patients with adenocarcinoma arising from the ampulla of Vater were excluded. Univariate and multivariate analyses were performed to identify clinicopathologic variables associated with survival and recurrence after resection. RESULTS:From 1984 to 2006, a total of 122 patients with duodenal adenocarcinoma underwent pancreaticoduodenectomy. Overall survival after resection was 48% at 5 years and 41% at 10 years. Five-year survival decreased as the number of lymph nodes involved by metastasis increased from 0 to 1-3 to ≥ 4 (68%, 58%, 17%, respectively, P < 0.01) and as the lymph node ratio increased from 0 to >0-0.2 to >0.2-0.4 to >0.4 (68%, 57%, 14%, 14%, respectively, P < 0.01). Lymph node metastasis was the only independent predictor of decreased survival in multivariate analysis. Recurrence after resection was predominantly distant (81%). Adjuvant chemoradiation did not decrease local recurrence or prolong overall survival; however, patients who received chemoradiation more commonly had nodal metastasis (P = 0.03). CONCLUSIONS:The prognostic significance of both the absolute number and ratio of involved lymph nodes emphasizes the need for adequate lymphadenectomy to accurately stage duodenal adenocarcinoma. The mostly distant pattern of recurrence underscores the need for the development of effective systemic therapies.

OBJECTIVE:To compare laparoscopic distal pancreatectomy (LDP) versus open distal pancreatectomy (ODP) by using meta-analytical techniques. BACKGROUND:LDP is increasingly performed as an alternative approach for distal pancreatectomy in selected patients. Multiple studies have tried to assess the safety and efficacy of LDP compared with ODP. METHODS:A systematic review of the literature was performed to identify studies comparing LDP and ODP. Intraoperative outcomes, postoperative recovery, oncologic safety, and postoperative complications were evaluated. Meta-analysis was performed using a random-effects model. RESULTS:Eighteen studies matched the selection criteria, including 1814 patients (43% laparoscopic, 57% open). LDP had lower blood loss by 355 mL (P < 0.001) and hospital length of stay by 4.0 days (P < 0.001). Overall complications were significantly lower in the laparoscopic group (33.9% vs 44.2%; odds ratio [OR] = 0.73, 95% confidence interval [CI] 0.57-0.95), as was surgical site infection (2.9% vs 8.1%; OR = 0.45, 95% CI 0.24-0.82). There was no difference in operative time, margin positivity, incidence of postoperative pancreatic fistula, and mortality. CONCLUSIONS:LDP has lower blood loss and reduced length of hospital stay. There was a lower risk of overall postoperative complications and wound infection, without a substantial increase in the operative time. Although a thorough evaluation of oncological outcomes was not possible, the rate of margin positivity was comparable to the open technique. The improved complication profile of LDP, taken together with the lack of compromise of margin status, suggests that this technique is a reasonable approach in selected cancer patients.

BACKGROUND:Prognosis after surgery for pancreatic ductal adenocarcinoma (PDAC) is typically reported from the date of surgery. Survival estimates, however, are dynamic and may change based on the time already survived. The authors sought to assess conditional survival among a large cohort of patients who underwent resection of PDAC. METHODS:Between 1970 and 2008, 1822 patients who underwent resection for PDAC with curative intent were identified. Kaplan-Meier and Cox regression analyses were performed to validate established predictors of survival, and results were compared with 2-year conditional survival. RESULTS:Actuarial survival was 18% at 5 years, with a median survival of 18 months. Multivariate analysis revealed that tumor size, lymph node ratio, and positive margins were associated with worse survival (all P < .001). Differences in actuarial versus conditional survival estimates were greater the more years already survived by the patient. The 2-year conditional survival at 3 years-the probability of surviving to postoperative year 5 given that the patient had already survived 3 years-was 66% versus a 5-year actuarial survival calculated from the time of surgery of 18%. Stratification of 2-year conditional survival by lymph node ratio and margin status revealed that patients with high lymph node ratio or positive margins saw the greatest increase in 2-year conditional survival as more time elapsed (both P ≤ .01). CONCLUSIONS:Differences in actuarial versus conditional survival estimates were more pronounced based on the additional years already survived by the patient. Conditional survival may be a helpful tool in counseling patients with PDAC, as it is a more accurate assessment of future survival for those patients who have already survived a certain amount of time.

The international consensus guidelines for management of intraductal papillary mucinous neoplasm and mucinous cystic neoplasm of the pancreas established in 2006 have increased awareness and improved the management of these entities. During the subsequent 5 years, a considerable amount of information has been added to the literature. Based on a consensus symposium held during the 14th meeting of the International Association of Pancreatology in Fukuoka, Japan, in 2010, the working group has generated new guidelines. Since the levels of evidence for all items addressed in these guidelines are low, being 4 or 5, we still have to designate them "consensus", rather than "evidence-based", guidelines. To simplify the entire guidelines, we have adopted a statement format that differs from the 2006 guidelines, although the headings are similar to the previous guidelines, i.e., classification, investigation, indications for and methods of resection and other treatments, histological aspects, and methods of follow-up. The present guidelines include recent information and recommendations based on our current understanding, and highlight issues that remain controversial and areas where further research is required.

BACKGROUND:The incidence of hepatocellular carcinoma (HCC) is rising, and the options for surgical therapy of HCC have evolved recently, but use of surgical therapy has not been characterized on a representative, nationwide basis. We quantified trends in use, mortality, and patient and hospital characteristics for 3 surgical therapies for HCC (resection, ablation, and transplantation) in the United States from 1998 to 2008. METHODS:Hospital discharge data from the Nationwide Inpatient Sample were used to quantify procedure-related data for each year. Trends over time were summarized as the average annual percent change (AAPC) and corresponding 95% confidence interval (CI). RESULTS:The number of surgical procedures for HCC increased from 1416 to 6769 (AAPC, 13.5%; 95% CI, 10.2%-16.8%). Volumes increased for all surgical procedures, most notably for ablation (AAPC, 17.3%; 95% CI, 6.6%-29.2%) and transplantation (AAPC, 20.9%; 95% CI, 14.1%-28.1%). When analyzed as a proportion of total procedures, there were declines in the relative use of major hepatectomy (35% to 16%; AAPC, -7.2%, 95% CI, -8.8% to -5.6%) and wedge resection (37% to 22%; AAPC, -4.8%; 95% CI, -6.2% to -3.4%), while the proportion accounted for by transplantation increased (16% to 35%; AAPC, 4.4%; 95% CI, 0.2%-8.9%). Inpatient mortality decreased for each procedure individually and overall from 7.3% to 4.6% (AAPC, -7.7%; 95% CI, -10.8% to -4.5%), despite increasing age and comorbidity burden. CONCLUSIONS:The use of surgical therapy for HCC has increased dramatically over the last decade, with a relative shift away from liver resection and toward liver transplantation. These therapeutic modalities must be better targeted to make the most appropriate use of limited health care resources.

A better molecular characterization of intraductal papillary mucinous neoplasm (IPMN), the most frequent cystic precursor lesion of pancreatic adenocarcinoma, may have a pivotal role in its early detection and in the development of effective therapeutic strategies. BRG1, a central component of the chromatin remodeling complex SWI/SNF regulating transcription, is inactive in several malignancies. In this study, we evaluate the Brg1 expression in intraductal papillary mucinous neoplasm to better understand its role in the pancreatic carcinogenesis. Tissue microarrays of 66 surgically resected IPMNs were immunolabeled for the Brg1 protein. Expression patterns were then correlated with clinicopathologic parameters. Normal pancreatic epithelium strongly immunolabeled for Brg1. Reduced Brg1 expression was observed in 32 (53.3%) of the 60 evaluable IPMN lesions and occurred more frequently in high-grade IPMNs (13 of 17 showed loss; 76%) compared to intermediate-grade (15 of 29 showed loss; 52%) and low-grade IPMNs (4 of 14 showed loss; 28%) (P = .03). A complete loss of Brg1 expression was observed in 5 (8.3%) of the 60 lesions. Finally, a decrease in Brg1 protein expression was furthermore found in a low-passage noninvasive IPMN cell line by Western blot analysis. We did not observe correlation between Brg1 expression and IPMN subtype or with location of the cyst. We provide first evidence that Brg1 expression is lost in noninvasive cystic precursor lesions of pancreatic adenocarcinoma.

BACKGROUND:Data on readmission as well as the potential impact of length of stay (LOS) after colectomy for colon cancer remain poorly defined. The objective of the current study was to evaluate risk factors associated with readmission among a nationwide cohort of patients after colorectal surgery. STUDY DESIGN/METHODS:We identified 149,622 unique individuals from the Surveillance, Epidemiology, and End Results-Medicare dataset with a diagnosis of primary colorectal cancer who underwent colectomy between 1986 and 2005. In-hospital morbidity, mortality, LOS, and 30-day readmission were examined using univariate and multivariate logistic regression models. RESULTS:Primary surgical treatment consisted of right (37.4%), transverse (4.9%), left (10.5%), sigmoid (22.8%), abdominoperineal resection (7.3%), low anterior resection (5.6%), total colectomy (1.2%), or other/unspecified (10.3%). Mean patient age was 76.5 years and more patients were female (52.9%). The number of patients with multiple preoperative comorbidities increased over time (Charlson comorbidity score ≥3: 1986 to 1990, 52.5% vs 2001 to 2005, 63.1%; p < 0.001). Mean LOS was 11.7 days and morbidity and mortality were 36.5% and 4.2%, respectively. LOS decreased over time (1986 to 1990, 14.0 days; 1991 to 1995, 12.0 days; 1996 to 2000, 10.4 days; 2001 to 2005, 10.6 days; p < 0.001). In contrast, 30-day readmission rates increased (1986 to 1990, 10.2%; 1991 to 1995, 10.9%; 1996 to 2000, 12.4%; 2001 to 2005, 13.7%; p < 0.001). Factors associated with increased risk of readmission included LOS (odds ratio = 1.02), Charlson comorbidities ≥3 (odds ratio = 1.27), and postoperative complications (odds ratio = 1.17) (all p < 0.01). CONCLUSIONS:Readmission rates after colectomies have increased during the past 2 decades and mean LOS after this operation has declined. More research is needed to understand the balance and possible trade off between these hospital performance measures for all surgical procedures.

BACKGROUND:Identifying pancreatic cancer patients at high risk of early mortality following pancreaticoduodenectomy (PD) is important for treatment decisions in a multidisciplinary setting. This study examines the preoperative predictors of early mortality following PD and combines these variables into an early mortality risk score (EMRS). METHODS:Medical records of patients who underwent PD for pancreatic adenocarcinoma at the Johns Hopkins Hospital between 30 August 1993 and 28 February 2005 were reviewed. Cox proportional hazards analysis was performed to identify predictors of early mortality, defined as death at 9 and 12 months. EMRS was constructed from univariate associated risk factors (age >75 years, tumor size ≥ 3 cm, poor differentiation, co-morbid diseases) with each factor assigned 1 point (range of 0-4). EMRS was evaluated as an independent predictor of death at 9 and 12 months. RESULTS:On univariate analysis, risk factors for death at 9 months included age ≥ 75 years (RR, 1.6; p = .009), comorbid disease (RR, 1.5; p = 0.020), tumor ≥ 3 cm (RR, 1.4; P = 0.050), and poor differentiation (RR, 2.1; P < 0.001). EMRS was associated with early mortality among those who did (p = 0.038) and did not receive adjuvant treatment (p < 0.001). A modified EMRS without tumor differentiation was also associated with early mortality (p < 0.001). Results persisted when reanalyzed using death at 12 months. CONCLUSIONS:EMRS may identify patients at risk of early mortality following PD who may be candidates for alternatively sequenced treatment protocols. Prospective validation of this EMRS is needed.