Tommy Ivanics

Implications of CA19-9 elevation for survival, staging, and treatment sequencing in intrahepatic cholangiocarcinoma: A national cohort analysis

Optimal management of patients with intrahepatic cholangiocarcinoma (ICCA) and elevated CA19‐9 remains undefined. We hypothesized CA19‐9 elevation above normal indicates aggressive biology and that inclusion of CA19‐9 would improve staging discrimination.

Impact of delay between imaging and treatment in patients with potentially curable pancreatic cancer

Locoregional pancreatic ductal adenocarcinoma (PDAC) may progress rapidly and/or disseminate despite having an early stage at diagnostic imaging. A prolonged interval from imaging to resection might represent a risk factor for encountering tumour progression at laparotomy. The aim of this study was to determine the therapeutic window for timely surgical intervention.

MicroRNAs in the cholangiopathies: Pathogenesis, diagnosis, and treatment

The cholangiopathies are a group of liver diseases resulting from different etiologies but with the cholangiocyte as the primary target. As a group, the cholangiopathies result in significant morbidity and mortality and represent one of the main indications for liver transplant in both children and adults. Contributing to this situation is the absence of a thorough understanding of their pathogenesis and a lack of adequate diagnostic and prognostic biomarkers. MicroRNAs are small non-coding RNAs that modify gene expression post-transcriptionally. They have been implicated in the pathogenesis of many diseases, including the cholangiopathies. Thus, in this review we provide an overview of the literature on miRNAs in the cholangiopathies and discuss future research directions.

Prognosis following surgical bypass compared with laparotomy alone in unresectable pancreatic adenocarcinoma.

Resection with curative intent has been shown to prolong survival of patients with locoregional pancreatic ductal adenocarcinoma (PDAC). However, up to 33 per cent of patients are deemed unresectable at exploratory laparotomy owing to unanticipated locally advanced or metastatic disease. In these patients, prophylactic double bypass (PDB) procedures have been considered the standard of care. The aim of this study was to compare PDB with exploratory laparotomy alone in terms of impact on postoperative course, chemotherapy and overall survival.

Adjuvant systemic therapy after resection of node positive gallbladder cancer: Time for a well-designed trial? (Results of a US-national retrospective cohort study)

BACKGROUND Ideal oncologic management of gallbladder carcinoma (GBCA) after complete surgical resection is unclear. We sought to define benefit of post-resection adjuvant systemic chemotherapy alone in T2 or greater gallbladder carcinoma utilising a large national dataset. STUDY DESIGN The National Cancer Data Base (NCDB) 2004-2012 cohort was retrospectively reviewed for patients with GBCA (T2+) undergoing curative-intent resection and surviving at least 6 weeks. Univariate group comparisons, unadjusted Kaplan-Meier and adjusted Cox proportional hazards analyzed overall survival. RESULTS 4373 patients were included (N = 2479 T2, N = 1894 T3/4). Overall, 22.1% of patients received adjuvant chemotherapy. Use of multi-agent chemotherapy increased during the study period. Patients receiving adjuvant therapy were younger, had fewer comorbidities, more often node-positive and more likely R1-margins than those receiving surgery alone. Unadjusted overall survival was improved in all patients with node-positive disease as well as for those with inadequate nodal staging. The benefit of chemotherapy persisted after adjustment for patient and tumor factors. CONCLUSION Adjuvant systemic chemotherapy is associated with survival benefit in patients with T2 or greater GBCA with node positive disease. We recommend a multidisciplinary approach in these patients as less than 1-in-4 of them currently receive adjuvant chemotherapy. Future clinical trials should address adjuvant chemotherapy in node positive GBCA.

Small Cell Carcinoma of the Pancreas: A Surgical Disease

Objectives Primary pancreatic small cell carcinomas (PSCCs) are rare, and benefits of surgery are unknown. Utilizing the National Cancer Data Base, surgical outcomes of PSCC were determined and compared with pancreatic ductal adenocarcinoma (PDAC). Methods Patients with histologically confirmed PSCC (n = 541) and PDAC (n = 156,733) were identified from the National Cancer Data Base (1998–2011). Parametric comparisons of patient and outcomes data were made. Unadjusted Kaplan-Meier and Cox proportional hazards analyses were performed. Results Primary pancreatic small cell carcinomas accounted for 0.2% of all pancreatic tumors. Demographics were similar to PDAC. A higher proportion of PSCC were metastatic at diagnosis (75.6% vs 53.6%, P < 0.001). In stage I/II, 45.6% of PDAC versus 21.8% of PSCC underwent surgery. Node status, lymphovascular invasion, margin negativity rates, and perioperative outcomes were similar. Median unadjusted overall survival was similar for resected PDAC and PSCC (16.9 vs 20.7 months; P = 0.337). On multivariable analysis within resectable PSCC (stages I-II), the greatest independent predictors of mortality were age 65 years or older (hazards ratio, 2.78; 95% confidence interval, 1.56–4.97; P = 0.00055) and nonreceipt of surgery (hazards ratio, 2.66; 95% confidence interval, 1.24–5.71; P = 0.01). Conclusions Although PSCC commonly presents with distant disease, patients with anatomically resectable tumors derive similar benefit from aggressive surgical intervention as PDAC and should be counseled accordingly.

Successful Secondary Engraftment of Pancreatic Ductal Adenocarcinoma and Cholangiocarcinoma Patient-Derived Xenografts After Previous Failed Primary Engraftment

BACKGROUND: Patient-derived xenografts (PDX) provide histologically accurate cancer models that recapitulate patient malignant phenotype and allow for highly correlative oncologic in-vivo downstream translational studies. Primary PDX engraftment failure has significant negative consequences on programmatic efficiency and resource utilization and is due to either no tumor growth or development of lymphoproliferative tumors. We aimed to determine if secondary engraftment of previously cryopreserved patient tumor tissues would allow salvage of PDX models that failed previous primary engraftment and increase overall engraftment efficiency. METHODS: Patient hepatobiliary and pancreatic cancers that failed primary engraftment were identified. Previously cryopreserved primary patient cancerous tissues were implanted into immunodeficient mice (NOD/SCID). Mice were monitored, growth metrics calculated, and secondary engraftment outcomes were recorded. Established PDX were verified and compared to original patient tissue through multiple generations by a GI pathologist. RESULTS: We identified 55 patient tumors that previously failed primary engraftment: no tumor growth (n = 46, 84%) or lymphoproliferative tumor (LT) (n = 9, 16%). After secondary implantation using cryopreserved patient tissues, 29 new histologically validated PDX models were generated with an overall secondary engraftment rate of 53% for all tumor types with greatest yield in pancreatic and biliary tract cancers. Of the secondary engraftment failures (n = 26), 21 (38%) were due to no growth and 5 (9%) developed LT. CONCLUSION: Secondary PDX engraftment using cryopreserved primary cancerous is feasible after previous failed engraftment attempts and can result in a 50% increase in overall engraftment efficiency with decreases in LT formation. This technique allows for salvage of critical patient PDX models that would otherwise not exist. SYNOPSIS: Patient-derived xenografts have many important translational applications however can be limited by engraftment failure. We demonstrate optimized methodology utilizing cryopreservation of primary tumor tissue that allows for subsequent successful secondary engraftment and creation of PDX models that failed previous primary engraftment and allowed salvage of patient PDX models that would otherwise not exist.

Patient-derived xenograft cryopreservation and reanimation outcomes are dependent on cryoprotectant type

Patient-derived xenografts (PDX) are being increasingly utilized in preclinical oncologic research. Maintaining large colonies of early generation tumor-bearing mice is impractical and cost-prohibitive. Optimal methods for efficient long-term cryopreservation and subsequent reanimation of PDX tumors are critical to any viable PDX program. We sought to compare the performance of “Standard” and “Specialized” cryoprotectant media on various cryopreservation and reanimation outcomes in PDX tumors. Standard (10% DMSO media) and Specialized (Cryostor®) media were compared between overall and matched PDX tumors. Primary outcome was reanimation engraftment efficiency (REE). Secondary outcomes included time to tumor formation (TTF), time to harvest (TTH), and potential loss of unique PDX lines. Overall 57 unique PDX tumors underwent 484 reanimation engraftment attempts after previous cryopreservation. There were 10 unique PDX tumors cryopreserved with Standard (71 attempts), 40 with Specialized (272 attempts), and 7 with both (141 attempts). Median frozen time of reanimated tumors was 29 weeks (max. 177). Tumor pathology, original primary PDX growth rates, frozen storage times, and number of implantations per PDX model were similar between cryoprotectant groups. Specialized media resulted in superior REE (overall: 82 vs. 39%, p < 0.0001; matched: 97 vs. 36%, p < 0.0001; >52 weeks cryostorage: 59 vs. 9%, p < 0.0001), shorter TTF (overall 24 vs. 54 days, p = 0.0051; matched 18 vs. 53 days, p = 0.0013) and shorter TTH (overall: 64 vs. 89 days, p = 0.009; matched: 47 vs. 88 days, p = 0.0005) compared to Standard. Specialized media demonstrated improved REE with extended duration cryostorage (p = 0.048) compared to Standard. Potential loss of unique PDX lines was lower with Specialized media (9 vs. 35%, p = 0.017). In conclusion, cryopreservation with a specialized cryoprotectant appears superior to traditional laboratory-based media and can be performed with reliable reanimation even after extended cryostorage.