The BET bromodomain inhibitor JQ1 suppresses growth of pancreatic ductal adenocarcinoma in patient-derived xenograft models

The primary aim of this study was to evaluate the antitumor efficacy of the bromodomain inhibitor JQ1 in pancreatic ductal adenocarcinoma (PDAC) patient-derived xenograft (tumorgraft) models. A secondary aim of the study was to evaluate whether JQ1 decreases expression of the oncogene c-Myc in PDAC tumors, as has been reported for other tumor types. We used five PDAC tumorgraft models that retain specific characteristics of tumors of origin to evaluate the antitumor efficacy of JQ1. Tumor-bearing mice were treated with JQ1 (50 mg/kg daily for 21 or 28 days). Expression analyses were performed with tumors harvested from host mice after treatment with JQ1 or vehicle control. An nCounter PanCancer Pathways Panel (NanoString Technologies) of 230 cancer-related genes was used to identify gene products affected by JQ1. Quantitative RT-PCR, immunohistochemistry and immunoblots were carried out to confirm that changes in RNA expression reflected changes in protein expression. JQ1 inhibited the growth of all five tumorgraft models (P<0.05), each of which harbors a KRAS mutation; but induced no consistent change in expression of c-Myc protein. Expression profiling identified CDC25B, a regulator of cell cycle progression, as one of the three RNA species (TIMP3, LMO2 and CDC25B) downregulated by JQ1 (P<0.05). Inhibition of tumor progression was more closely related to decreased expression of nuclear CDC25B than to changes in c-Myc expression. JQ1 and other agents that inhibit the function of proteins with bromodomains merit further investigation for treating PDAC tumors. Work is ongoing in our laboratory to identify effective drug combinations that include JQ1.

Outcomes after implementing a tailored endoscopic step-up approach to walled-off necrosis in acute pancreatitis

BACKGROUND

The aim of the study was to compare the outcomes of patients with pancreatic or peripancreatic walled-off necrosis by endoscopy using the conventional approach versus an algorithmic approach based on the collection size, location and stepwise response to intervention.

METHODS

This was an observational before-after study of consecutive patients managed over two time intervals. In the initial period (2004-2009) symptomatic patients with walled-off necrosis underwent conventional single transmural drainage with placement of two stents and a nasocystic catheter, followed by direct endoscopic necrosectomy, if required. In the later period (2010-2013) an algorithmic approach was adopted based on size and extent of the walled-off necrosis and stepwise response to intervention. The main outcome was treatment success, defined as a reduction in walled-off necrosis size to 2 cm or less on CT after 8 weeks.

RESULTS

Forty-seven patients were treated in the first interval and 53 in the second. There was no difference in patient demographics, clinical or walled-off necrosis characteristics and laboratory parameters between the groups, apart from a higher proportion of women and Caucasians in the later period. The treatment success rate was higher for the algorithmic approach compared with conventional treatment (91 versus 60 per cent respectively; P < 0·001). On multivariable logistic regression, management based on the algorithm was the only predictor of treatment success (odds ratio 6·51, 95 per cent c.i. 2·19 to 19·37; P = 0·001).

CONCLUSION

An algorithmic approach to pancreatic and peripancreatic walled-off necrosis, based on the collection size, location and stepwise response to intervention, resulted in an improved rate of treatment success compared with conventional endoscopic management.

Prognostic factors relating to esophageal cancer

Prognostic factors for esophageal cancer are difficult to assess because of the lack of standardization and small number of cases over the years. With the increase in number of adenocarcinoma as well as larger amounts of data, there has been a surge in the amount of information regarding this disease. The most significant relationship is between lymph nodes and survival. As the treatment options for esophageal cancer improve the staging of the lymph nodes will become more important in terms of number and ratio. The method of surgical removal is trending toward radical excision, but the prognosis is still poor. With the advent of molecular markers and better chemotherapeutic agents, we will be able to tailor our treatment with respect to the individual tumor.

Prognostic factors associated with resectable adenocarcinoma of the head of the pancreas

A retrospective study of patients with surgically resectable adenocarcinoma of the pancreatic head was undertaken to determine which prognostic factors are independently associated with improved survival. Thirty-four men and 41 women (mean age, 61.9 years) had resection for adenocarcinoma of the pancreatic head between 1980 and 1997 at Rush-Presbyterian-St. Luke's Medical Center. Surgical resections included 15 total pancreatectomies, 43 pyloric-preserving procedures, and 17 standard Whipple procedures. Thirty-six patients received adjuvant radiation and/or chemotherapy. Overall median survival was 13 months, with a 5-year survival of 17 per cent. Thirty-day surgical mortality was 1.3 per cent. Significant factors that negatively influenced survival using univariate Kaplan-Meier analysis were: positive resection margin (P = 0.01), intraoperative blood transfusion (P = 0.01), and lymph node metastases (P = 0.01). Presenting signs and symptoms, patient demographics, operative procedure, tumor size, histologic differentiation, and adjuvant therapy did not have a significant impact on survival. Using multivariate Cox regression analysis, the only significant independent factors improving survival were the absence of intraoperative blood transfusion (P = 0.02) and a negative resection margin (P = 0.04). Performing pancreaticoduodenectomy for adenocarcinoma of the head of the pancreas with negative microscopic margins of resection and without intraoperative transfusion significantly improves survival.