Faculty Bibliography

BACKGROUND:The incidence of occult metastatic disease (OMD) in pancreatic ductal adenocarcinoma (PDAC) and associated risk factors are largely unknown. METHODS:We identified all patients with PDAC, who had an aborted oncologic operation due to OMD within a 10-year period. The cases were matched to a cohort of resected PDAC patients on a 1:3 ratio, based on age and sex, for comparison of preoperative clinical characteristics and potential risk factors for OMD. RESULTS:In the studied period, 117 patients with OMD were identified in 1423 pancreatectomies performed for PDAC (8%). Liver metastases were the most common finding (79%) followed by peritoneal implants (16%). When compared with non-OMD cases, patients with OMD presented more often with abdominal pain (P < 0.001), and higher preoperative carbohydrate antigen 19-9 (CA 19-9) values ( P = 0.007). Additionally, indeterminate liver lesions on preoperative computed tomography (CT) were identified in 40% of OMD versus 17% of non-OMD patients ( P < 0.001). Multivariable analysis distinguished four independent predictors for OMD: indeterminate lesions on preoperative CT, tumor size > 30 mm, abdominal pain, and preoperative CA 19-9 > 192 U/mL. CONCLUSIONS:Occurrence of OMD in PDAC accounts for 8% of cases. Preoperative CA 19-9 > 192 U/mL, primary tumor size > 30 mm, and identification of indeterminate lesions in preoperative CT may indicate the need for diagnostic laparoscopy.

Context:McCune-Albright syndrome (MAS) is a rare disorder characterized by fibrous dysplasia of bone, café-au-lait macules, and hyperfunctioning endocrinopathies. It arises from somatic gain-of-function mutations in GNAS, which encodes the cAMP-regulating protein Gαs. Somatic GNAS mutations have been reported in intraductal papillary mucinous neoplasms (IPMNs) and various gastrointestinal (GI) tumors. The clinical spectrum and prevalence of MAS-associated GI disease is not well established. Objective:Define the spectrum and prevalence of MAS-associated GI pathology in a large cohort of patients with MAS. Design:Cross-sectional study. Setting:National Institutes of Health Clinical Center and The Johns Hopkins Hospital. Methods:Fifty-four consecutive subjects with MAS (28 males; age range, 7 to 67 years) were screened with magnetic resonance cholangiopancreatography (MRCP). Results:Thirty of 54 subjects (56%) had radiographic GI abnormalities. Twenty-five (46%) of the screened subjects had IPMNs (mean age of 35.1 years). Fourteen of the 25 had IPMNs alone, and 11 had IPMNs and abnormal hepatobiliary imaging. The 30 patients with MAS-associated GI pathology had a higher prevalence of acute pancreatitis, diabetes mellitus, and skeletal disease burden of fibrous dysplasia than patients without GI disease. Conclusions:A broad spectrum of GI pathology is associated with MAS. IPMNs are common and occur at a younger age than in the general population. Patients with MAS should be considered for screening with a focused GI history and baseline MRCP. Further determination of the natural history and malignant potential of IPMNs in MAS is needed.

Invasive pancreatic ductal adenocarcinoma (PDAC) can infiltrate back into and spread along preexisting pancreatic ducts and ductules in a process known as cancerization of ducts (COD). Histologically COD can mimic high-grade pancreatic intraepithelial neoplasia (HG-PanIN). We reviewed pancreatic resections from 100 patients with PDAC for the presence or absence of ducts with histologic features of COD. Features supporting COD included adjacent histologically similar invasive PDAC and an abrupt transition between markedly atypical intraductal epithelium and normal duct epithelium or circumferential involvement of a duct. As the TP53 and SMAD4 genes are frequently targeted in invasive PDAC but not HG-PanIN, paired PDAC and histologically suspected COD lesions were immunolabeled with antibodies to the p53 and Smad4 proteins. Suspected COD was identified on hematoxylin and eosin sections in 89 (89%) of the cases. Immunolabeling for p53 and Smad4 was performed in 68 (76%) of 89 cases. p53 was interpretable in 55 cases and all 55 (100%) cases showed concordant labeling between COD and invasive PDAC. There was matched aberrant p53 immunolabeling in 37 (67%) cases including overexpression in 30 (55%) cases and lack of expression in 7 (13%) cases. Smad4 immunolabeling was interpretable in 61 cases and 59 (97%) cases showed concordant labeling between COD and invasive PDAC. Matched loss of Smad4 was seen in 28 (46%) cases. The immunolabeling of invasive PDAC and COD for p53 and Smad4 supports the high prevalence of COD observed on hematoxylin and eosin and highlights the utility of p53 and Smad4 immunolabeling in differentiating COD and HG-PanIN.

OBJECTIVE:The aim of this study was to identify a readily available, reproducible, and internationally applicable cost assessment tool for surgical procedures. SUMMARY OF BACKGROUND DATA:Strong economic pressure exists worldwide to slow down the rising of health care costs. Postoperative morbidity significantly impacts on cost in surgical patients. The comprehensive complication index (CCI), reflecting overall postoperative morbidity, may therefore serve as a new marker for cost. METHODS:Postoperative complications and total costs from a single tertiary center were prospectively collected (2014 to 2016) up to 3 months after surgery for a variety of abdominal procedures (n = 1388). CCI was used to quantify overall postoperative morbidity. Pearson correlation coefficient (rpears) was calculated for cost and CCI. For cost prediction, a linear regression model based on CCI, age, and type of surgery was developed and validated in an international cohort of patients. RESULTS:We found a high correlation between CCI and overall cost (rpears = 0.75) with the strongest correlation for more complex procedures. The prediction model performed very well (R = 0.82); each 10-point increase in CCI corresponded to a 14% increase to the baseline cost. Additional 12% of baseline cost must be added for patients older than 50 years, or 24% for those over 70 years. The validation cohorts showed a good match of predicted and observed cost. CONCLUSION:Overall postoperative morbidity correlates highly with cost. The CCI together with the type of surgery and patient age is a novel and reliable predictor of expenses in surgical patients. This finding may enable objective cost comparisons among centers, procedures, or over time obviating the need to look at complex country-specific cost calculations (www.assessurgery.com).

BACKGROUND/AIM/OBJECTIVE:Radiofrequency ablation (RFA) is thought to result in inferior prognosis than hepatic resection among patients with colorectal liver metastasis (CRLM). However, resection plus RFA may be an option for patients with a large number of tumors (≥4 liver lesions) and borderline resectability. MATERIALS AND METHODS/METHODS:A total of 717 patients with CRLM who underwent hepatic resection +/- RFA at two tertiary institutions between 09/01/2000-12/01/2015 were eligible for inclusion in this study. RESULTS:Among patients with <4 lesions (n=568), OS in the resection + RFA group (n=48) was significantly worse than in the resection alone group (n=520) (5-year OS: 34.4 % versus 58.9%, p=0.007). Conversely, in patients with ≥4 lesions, OS in the resection + RFA (n=68) and resection alone(n=81) groups were not significantly different (5-year OS: 31.9% versus 34.1%, p=0.48). In patients with <4 lesions, carcinoembryonic antigen (CEA) ≥30 ng/ml, extrahepatic metastasis, preoperative chemotherapy and resection + RFA were independently associated with poor prognosis. Interestingly, in patients with ≥4 lesions, positive primary lymph nodes, KRAS mutation, CEA ≥30 ng/ml and extrahepatic metastasis were independent predictors of poor prognosis; however, the combination of hepatic resection with RFA was not associated with worse survival (p=0.93). CONCLUSION/CONCLUSIONS:Although surgeons should always strive for R0 resection when feasible, combined resection and RFA may be a viable alternative for CRLM patients with a large number of tumors.

Purpose/UNASSIGNED:For patients with localized pancreatic cancer (PC) with vascular involvement, prediction of resectability is critical to define optimal treatment. However, the current definitions of borderline resectable (BR) and locally advanced (LA) disease leave considerable heterogeneity in outcomes within these classifications. Moreover, factors beyond vascular involvement likely affect the ability to undergo resection. Herein, we share our experience developing a model that incorporates detailed radiologic, patient, and treatment factors to predict surgical resectability in patients with BR and LA PC who undergo stereotactic body radiation therapy (SBRT). Methods and materials/UNASSIGNED:Patients with BR or LA PC who were treated with SBRT between 2010 and 2016 were included. The primary endpoint was margin negative resection, and predictors included age, sex, race, treatment year, performance status, initial staging, tumor volume and location, baseline and pre-SBRT carbohydrate antigen 19-9 levels, chemotherapy regimen and duration, and radiation dose. In addition, we characterized the relationship between tumors and key arteries (superior mesenteric, celiac, and common hepatic arteries), using overlap volume histograms derived from computed tomography data. A classification and regression tree was built, and leave-one-out cross-validation was performed. Prediction of surgical resection was compared between our model and staging in accordance with the National Comprehensive Care Network guidelines using McNemar's test. Results/UNASSIGNED:< .05). Conclusions/UNASSIGNED:We demonstrate the ability to improve prediction of surgical resectabiliy beyond the current staging guidelines, which highlights the value of assessing vascular involvement in a continuous manner. In addition, we show an association between radiation dose and resectability, which suggests the potential importance of radiation to allow for resection in certain populations. External data are needed for validation and to increase the robustness of the model.

Pancreatic cancer is the most lethal common solid malignancy. Systemic therapies are often ineffective, and predictive biomarkers to guide treatment are urgently needed. We generated a pancreatic cancer patient-derived organoid (PDO) library that recapitulates the mutational spectrum and transcriptional subtypes of primary pancreatic cancer. New driver oncogenes were nominated and transcriptomic analyses revealed unique clusters. PDOs exhibited heterogeneous responses to standard-of-care chemotherapeutics and investigational agents. In a case study manner, we found that PDO therapeutic profiles paralleled patient outcomes and that PDOs enabled longitudinal assessment of chemosensitivity and evaluation of synchronous metastases. We derived organoid-based gene expression signatures of chemosensitivity that predicted improved responses for many patients to chemotherapy in both the adjuvant and advanced disease settings. Finally, we nominated alternative treatment strategies for chemorefractory PDOs using targeted agent therapeutic profiling. We propose that combined molecular and therapeutic profiling of PDOs may predict clinical response and enable prospective therapeutic selection.Significance: New approaches to prioritize treatment strategies are urgently needed to improve survival and quality of life for patients with pancreatic cancer. Combined genomic, transcriptomic, and therapeutic profiling of PDOs can identify molecular and functional subtypes of pancreatic cancer, predict therapeutic responses, and facilitate precision medicine for patients with pancreatic cancer. Cancer Discov; 8(9); 1112-29. ©2018 AACR.See related commentary by Collisson, p. 1062This article is highlighted in the In This Issue feature, p. 1047.

OBJECTIVE:Intraductal papillary mucinous neoplasms (IPMNs) are precursor lesions that can give rise to invasive pancreatic carcinoma. Although approximately 8% of patients with resected pancreatic ductal adenocarcinoma have a co-occurring IPMN, the precise genetic relationship between these two lesions has not been systematically investigated. DESIGN:We analysed all available patients with co-occurring IPMN and invasive intrapancreatic carcinoma over a 10-year period at a single institution. For each patient, we separately isolated DNA from the carcinoma, adjacent IPMN and distant IPMN and performed targeted next generation sequencing of a panel of pancreatic cancer driver genes. We then used the identified mutations to infer the relatedness of the IPMN and co-occurring invasive carcinoma in each patient. RESULTS:We analysed co-occurring IPMN and invasive carcinoma from 61 patients with IPMN/ductal adenocarcinoma as well as 13 patients with IPMN/colloid carcinoma and 7 patients with IPMN/carcinoma of the ampullary region. Of the patients with co-occurring IPMN and ductal adenocarcinoma, 51% were likely related. Surprisingly, 18% of co-occurring IPMN and ductal adenocarcinomas were likely independent, suggesting that the carcinoma arose from an independent precursor. By contrast, all colloid carcinomas were likely related to their associated IPMNs. In addition, these analyses showed striking genetic heterogeneity in IPMNs, even with respect to well-characterised driver genes. CONCLUSION:This study demonstrates a higher prevalence of likely independent co-occurring IPMN and ductal adenocarcinoma than previously appreciated. These findings have important implications for molecular risk stratification of patients with IPMN.

BACKGROUND:Despite strong evidence demonstrating the clinical and economic benefits of minimally invasive surgery (MIS), utilization of MIS in the Medicare population is highly variable and tends to be lower than in the general population. We sought to compare the post-operative and economic outcomes of MIS versus open surgery for seven common surgical procedures in the Medicare population. METHODS:Using the 2014 Medicare Provider Analysis and Review Inpatient Limited Data Set, patients undergoing bariatric, cholecystectomy, colectomy, hysterectomy, inguinal hernia, thoracic, and ventral hernia procedures were identified using DRG and ICD-9 codes. Adjusting for patient demographics and comorbidities, the odds of complication and all-cause 30-day re-admission were compared among patients undergoing MIS versus open surgery stratified by operation type. A generalized linear model was used to calculate the estimated difference in length of stay (LOS), Medicare claim cost, and Medicare reimbursement. RESULTS:Among 233,984 patients, 102,729 patients underwent an open procedure versus 131,255 who underwent an MIS procedure. The incidence of complication after MIS was lower for 5 out of the 7 procedures examined (OR 0.36-0.69). Re-admission was lower for MIS for 6 out of 7 procedures (OR 0.43-0.87). MIS was associated with shorter LOS for 6 procedures (point estimate range 0.35-2.47 days shorter). Medicare claim costs for MIS were lower for 4 (range $3010.23-$4832.74 less per procedure) and Medicare reimbursements were lower for 3 (range $841.10-$939.69 less per procedure). CONCLUSIONS:MIS benefited Medicare patients undergoing a range of surgical procedures. MIS was associated with fewer complications and re-admissions as well as shorter LOS and lower Medicare costs and reimbursements versus open surgery. MIS may represent a better quality and cost proposition in the Medicare population.