Faculty Bibliography

BACKGROUND: The receptor for advanced glycation end-products (RAGE) is implicated in pancreatic tumorigenesis. Activating Kras mutations and p16 inactivation are genetic abnormalities most commonly detected as pancreatic ductal epithelium progresses from intraepithelial neoplasia (PanIN) to adenocarcinoma (PDAC). OBJECTIVE: The aim of this study was to evaluate the effect of RAGE (or AGER) deletion on the development of PanIN and PDAC in conditional Kras ( G12D ) mice. MATERIALS AND METHODS: Pdx1-Cre; LSL-Kras ( G12D/+) mice were crossed with RAGE (-/-) mice to generate Pdx1-Cre; LSL-Kras ( G12D/+) ; RAGE (-/-) mice. Pdx1-Cre; LSL-Kras ( G12D/+); p16 ( Ink4a-/-) mice were crossed with RAGE (-/-) mice to generate Pdx1-Cre; LSL-Kras ( G12D/+); p16 ( Ink4a-/-); RAGE (-/-) mice. Pancreatic ducts were scored and compared to the relevant RAGE (+/+) controls. RESULTS: At 16 weeks of age, Pdx1-Cre; LSL-Kras ( G12D/+); RAGE (-/-) mice had significantly fewer high-grade PanIN lesions than Pdx1-Cre; LSL-Kras ( G12D/+); RAGE (+/+) controls. At 12 weeks of age, none of the Pdx1-Cre; LSL-Kras ( G12D/+); p16 ( Ink4a-/-); RAGE (-/-) mice had PDAC compared to a 45.5% incidence of PDAC in Pdx1-Cre; LSL-Kras ( G12D/+); p16 ( Ink4a-/-); RAGE (+/+) controls. Finally, Pdx1-Cre; LSL-Kras ( G12D/+); p16 ( Ink4a-/-); RAGE (-/-) mice also displayed markedly longer median survival. CONCLUSION: Loss of RAGE function inhibited the development of PanIN and progression to PDAC and significantly prolonged survival in these mouse models. Further work is needed to target the ligand-RAGE axis for possible early intervention and prophylaxis in patients at risk for developing pancreatic cancer

BACKGROUND:Studies suggest that while most pediatric thyroid nodules are benign, there is a higher rate of malignancy than in adults. We investigate clinical factors that may predict malignancy in pediatric thyroid nodules. METHODS:A retrospective review of 207 pediatric thyroidectomies was conducted over 15 years at 2 tertiary hospitals. Analyses examined predictive values of 16 clinicopathologic factors associated with cancer. Positive predictive values (PPVs) of fine-needle aspiration biopsy specimens (FNABs) were analyzed independently. RESULTS:Malignancy occurred in 41% of patients. After excluding missing data, malignancy was more likely with family history of thyroid cancer (34.2% vs 17.7%; P = .111), palpable lymphadenopathy (34.2% vs 2.9%; P = .001), and hypoechoic nodules (52.2% vs 19.2%; P = .016). Palpable lymphadenopathy indicated greater than 2-fold increased risk for malignancy (relative risk, 2.18; 95% confidence interval, 1.56-3.05). PPVs of FNAB results were 0.94 for malignancy, 0.63 for suspicious for malignancy, and 0.55 for indeterminate lesions. PPV for benign FNAB to be benign on final pathology was 0.71. CONCLUSION/CONCLUSIONS:While malignancy is associated with family history of thyroid cancer and hypoechoic lesions, palpable lymphadenopathy had the greatest risk. When compared to adults, a benign FNAB in children is not as accurate and the likelihood that an indeterminate nodule is cancer is greater.

Pancreatic cancer, as the 4th leading cause of cancer death in the U.S., remains a challenging disease for all oncologists. Less than 20% of all cases could be potentially cured by surgical resection, while the majority of cases are deemed either unresectable or metastatic upon diagnosis. In this year's American Society of Clinical Oncology (ASCO) Annual Meeting, several studies were presented with novel approaches towards treating locally advanced pancreatic cancer. The LAP-07 study, a large phase III study with two separate randomizations, updated their accrual status, but with no interim data yet reported (Abstract #e14619). A single institutional review study reported its promising results on the incorporation of interferon to chemoradiation, but the toxicities could be concerning (Abstract #e14648). Abstract #e14607 demonstrated promising survival data from a tri-modality approach incorporating local and systemic chemotherapy concurrent with external beam radiation as well as radiofrequency ablation. The tolerability of sorafenib in locally advanced pancreatic cancer was shown in a small phase I study (Abstract #e14525). CyberKnife® stereotactic body radiation therapy was investigated as a modality for local palliation (Abstract #e14506). More effective therapeutic agents and approaches are still needed in this difficult disease. This highlight article will focus on the management of locally advanced pancreatic cancer.

BACKGROUND:Most experts agree that primary hyperaldosteronism (PHA) caused by an aldosterone-producing adenoma (APA) is best treated by adrenalectomy. From a public health standpoint, the cost of treatment must be considered. We sought to compare the current guideline-based (surgical) strategy with universal pharmacologic management to determine the optimal strategy from a cost perspective. METHODS:A decision analysis was performed using a Markov state transition model comparing the strategies for PHA treatment. Pharmacologic management for all patients with PHA was compared with a strategy of screening for and resecting an aldosterone-producing adenoma. Success rates were determined for treatment outcomes based on a literature review. Medicare reimbursement rates were calculated to estimate costs from a third-party payer perspective. RESULTS:Screening for and resecting APAs was the least costly strategy in this model. For a reference patient with 41 remaining years of life, the discounted expected cost of the surgical strategy was $27,821. The discounted expected cost of the medical strategy was $34,691. The cost of adrenalectomy would have to increase by 156% to $22,525 from $8,784 for universal pharmacologic therapy to be less costly. Screening for APA is more costly if fewer than 9.6% of PHA patients have resectable APA. CONCLUSION/CONCLUSIONS:Resection of APAs was the least costly treatment strategy in this decision analysis model.

BACKGROUND:Traditional resections for benign and low-grade malignant neoplasms of the mid pancreas result in loss of normal parenchyma that can cause pancreatic endocrine and exocrine insufficiency. Central pancreatectomy (CP) is a parenchyma-sparing option for such lesions. This study evaluates a single institution's experience with CP and compares outcomes with distal pancreatectomy (DP). METHODS:We retrospectively collected data on CP patients from 1997 through 2009 and evaluated outcomes. In a subset of 50 patients, we performed a matched-pairs analysis to directly compare the short- and long-term outcomes of CP and DP. RESULTS:Seventy-three patients underwent CP with a median operating room time of 254 minutes. Overall morbidity was 41.1% with pancreatic fistula in 20.5%. Mortality was 0%. There were no differences in fistula, morbidity, and mortality rates between the CP and DP groups. The CP group had resected for smaller lesions. CP patients had a lower rate of new-onset and worsening diabetes than DP patients (14% vs 46%; P = .003). Of new-onset and worsening diabetics, only 1 CP patient required insulin compared with 14 DP patients (P = .002). CONCLUSION/CONCLUSIONS:CP is safe and effective for select neoplasms of the mid pancreas. Patients undergoing CP have markedly decreased insulin requirements compared with DP patients.

BACKGROUND: The receptor for advanced glycation end-products (RAGE) is a cell surface receptor implicated in tumor cell proliferation and migration. We hypothesized that RAGE signaling impacts tumorigenesis and metastatic tumor growth in murine models of colorectal carcinoma. MATERIALS AND METHODS: Tumorigenesis: Apc (1638N/+) mice were crossed with Rage (-/-) mice in the C57BL/6 background to generate Apc (1638N/+)/Rage (-/-) mice. Metastasis: BALB/c mice underwent portal vein injection with CT26 cells (syngeneic) and received daily soluble (s)RAGE or vehicle. Rage (-/-) mice and Rage (+/+) controls underwent portal vein injection with MC38 cells (syngeneic). Rage (+/+) mice underwent portal vein injection with MC38 cells after stable transfection with full-length RAGE or mock transfection control. RESULTS: Tumorigenesis: Apc (1638N/+)/Rage (-/-) mice had reduced tumor incidence, size, and histopathologic grade. Metastasis: Pharmacological blockade of RAGE with sRAGE or genetic deletion of Rage reduced hepatic tumor incidence, nodules, and burden. Gain of function by transfection with full-length RAGE increased hepatic tumor burden compared to vector control MC38 cells. CONCLUSION: RAGE signaling plays an important role in tumorigenesis and hepatic tumor growth in murine models of colorectal carcinoma. Further work is needed to target the ligand-RAGE axis for possible prophylaxis and treatment of primary and metastatic colorectal carcinoma