Faculty Bibliography

Accurate staging of pancreatic adenocarcinoma is a crucial step in determining the appropriate therapeutic approach to pancreatic cancer and to maximizing life expectancy. Despite the availability of high-quality abdominal imaging, the use of multi-modality imaging and of diagnostic laparoscopy, a portion of surgically explored patients fail to undergo resection secondary to metastatic disease. This review is an update from the 2012 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium of new developments in the staging of localized pancreatic adenocarcinoma. (Abstracts #168, #177, and #212).

Pancreatic adenocarcinoma is the fourth most common cause of cancer-related death among U.S. men and women. Despite much effort in translational research, pancreatic adenocarcinoma remains a challenging disease with an overall 5-year survival rate less than 5%. To date, the only potentially curative treatment for managing pancreatic adenocarcinoma is surgical resection. However, more than 80% of patients are deemed either unresectable or metastatic upon diagnosis. For borderline resectable disease, although there is no high-level evidence supporting its use, an initial approach involving neoadjuvant therapy is preferred, as opposed to immediate surgery. In this year's ASCO Gastrointestinal Cancers Symposium, several studies were presented with approaches towards treating borderline resectable pancreatic adenocarcinoma. Retrospective studies (Abstract #280, #304, #327) were presented and showed that neoadjuvant chemoradiation were associated with higher rates of negative margin resection and better survival. The tolerability of accelerated fraction radiotherapy with concomitant capecitabine was demonstrated in a phase I study (Abstract #329). More effective therapeutic approaches and prospective studies are needed for this devastating illness. This highlight article will focus on the management of borderline resectable pancreatic adenocarcinoma.

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.