Faculty Bibliography

BACKGROUND:Immune checkpoint inhibitors are not effective for pancreatic ductal adenocarcinoma (PDAC) as single agents. Vaccine therapy may sensitize PDACs to checkpoint inhibitor treatments. Annexin A2 (ANXA2) is a pro-metastasis protein, previously identified as a relevant PDAC antigen that is expressed by a GM-CSF-secreting allogenic whole pancreatic tumor cell vaccine (GVAX) to induce an anti-ANXA2 antibody response in patients with PDAC. We hypothesized that an ANXA2-targeting vaccine approach not only provokes an immune response but also mounts anti-tumor effects. METHODS:We developed a Listeria-based, ANXA2-targeting cancer immunotherapy (Lm-ANXA2) and investigated its effectiveness within two murine models of PDAC. RESULTS:We show that Lm-ANXA2 prolonged the survival in a transplant model of mouse PDACs. More importantly, priming with the Lm-ANXA2 treatment prior to administration of anti-PD-1 antibodies increased cure rates in the implanted PDAC model and resulted in objective tumor responses and prolonged survival in the genetically engineered spontaneous PDAC model. In tumors treated with Lm-ANXA2 followed by anti-PD-1 antibody, the T cells specific to ANXA2 had significantly increased INFγ expression. CONCLUSIONS:For the first time, a listeria vaccine-based immunotherapy was shown to be able to induce a tumor antigen-specific T cell response within the tumor microenvironment of a "cold" tumor such as PDAC and sensitize the tumor to checkpoint inhibitor therapy. Moreover, this combination immunotherapy led to objective tumor responses and survival benefit in the mice with spontaneously developed PDAC tumors. Therefore, our study supports developing Lm-ANXA2 as a therapeutic agent in combination with anti-PD-1 antibody for PDAC treatment.

BACKGROUND & AIMS:Many patients with pancreatic adenocarcinoma carry germline mutations associated with increased risk of cancer. It is not clear whether patients with intraductal papillary mucinous neoplasms (IPMNs), which are precursors to some pancreatic cancers, also carry these mutations. We assessed the prevalence of germline mutations associated with cancer risk in patients with histologically confirmed IPMN. METHODS:We obtained nontumor tissue samples from 315 patients with surgically resected IPMNs from 1997 through 2017, and we sequenced 94 genes with variants associated with cancer risk. Mutations associated with increased risk of cancer were identified and compared with individuals from the Exome Aggregation Consortium. RESULTS:We identified 23 patients with a germline mutation associated with cancer risk (7.3%; 95% confidence interval, 4.9-10.8). Nine patients had a germline mutation associated with pancreatic cancer susceptibility (2.9%; 95% confidence interval, 1.4-5.4). More patients with IPMNs carried germline mutations in ATM (P < .0001), PTCH1 (P < .0001), and SUFU (P < .0001) compared with controls. Patients with IPMNs and germline mutations associated with pancreatic cancer were more like to have concurrent invasive pancreatic carcinoma compared with patients with IPMNs without these mutations (P < .0320). CONCLUSIONS:In sequence analyses of 315 patients with surgically resected IPMNs, we found that almost 3% to carry mutations associated with pancreatic cancer risk. More patients with IPMNs and germline mutations associated with pancreatic cancer had concurrent invasive pancreatic carcinoma compared with patients with IPMNs without these mutations. Genetic analysis of patients with IPMNs might identify those at greatest risk for cancer.

This study aimed to understand the biology of pancreatic ductal adenocarcinoma that arises in the remnant pancreas after surgical resection of a primary pancreatic ductal adenocarcinoma, using integrated histological and molecular analysis. Patients who underwent a completion pancreatectomy for local recurrence following resection of a primary pancreatic ductal adenocarcinoma were studied with histological analysis and next-generation sequencing of the primary and the recurrent cancer. Of six patients that met the inclusion criteria, three cases were classified as "true" recurrences, i.e., the primary and the cancer in the remnant pancreas shared both morphological features and molecular alterations. Two cases were identified as having independent cancers that exhibited different histological and molecular profiles. In the remaining case, the relationship could not be determined. Pancreatic ductal adenocarcinoma that arises in the remnant pancreas can be either a second primary or a "true" relapse of the preceding primary. The differentiation of second primaries from local recurrences may have important implications for patient management.

BACKGROUND:Despite improvements in cancer management, most pancreatic cancers are still diagnosed at an advanced stage. We have recently identified promoter DNA methylation of the genes ADAMTS1 and BNC1 as potential blood biomarkers of pancreas cancer. In this study, we validate this biomarker panel in peripheral cell-free tumor DNA of patients with pancreatic cancer. RESULTS:Sensitivity and specificity for each gene are as follows: ADAMTS1 87.2% and 95.8% (AUC = 0.91; 95% CI 0.71-0.86) and BNC1 64.1% and 93.7% (AUC = 0.79; 95% CI 0.63-0.78). When using methylation of either gene as a combination panel, sensitivity increases to 97.3% and specificity to 91.6% (AUC = 0.95; 95% CI 0.77-0.90). Adding pre-operative CA 19-9 values to the combined two-gene methylation panel did not improve sensitivity. Methylation of ADAMTS1 was found to be positive in 87.5% (7/8) of stage I, 77.8% (7/9) of stage IIA, and 90% (18/20) of stage IIB disease. Similarly, BNC1 was positive in 62.5% (5/8) of stage I patients, 55.6% (5/9) of stage IIA, and 65% (13/20) of patients with stage IIB disease. The two-gene panel (ADAMTS1 and/or BNC1) was positive in 100% (8/8) of stage I, 88.9% (8/9) of stage IIA, and 100% (20/20) of stage IIB disease. The sensitivity and specificity of the two-gene panel for localized pancreatic cancer (stages I and II), where the cancer is eligible for surgical resection with curative potential, was 94.8% and 91.6% respectively. Additionally, the two-gene panel exhibited an AUC of 0.95 (95% CI 0.90-0.98) compared to 57.1% for CA 19-9 alone. CONCLUSION:The methylation status of ADAMTS1 and BNC1 in cfDNA shows promise for detecting pancreatic cancer during the early stages when curative resection of the tumor is still possible. This minimally invasive blood-based biomarker panel could be used as a promising tool for diagnosis and screening in a select subset of high-risk populations.

OBJECTIVE:Limited data exist on the impact of ascites in pancreatic ductal adenocarcinoma (PDAC). We evaluated the survival outcomes of patients with PDAC and ascites. METHODS:Retrospective, single-institution, case-control study including patients with newly diagnosed PDAC from 2007 to 2016. One hundred fifty-four patients with ascites at diagnosis (case group) and 154 controls were matched on age, sex, stage, Eastern Cooperative Oncology Group performance, surgical treatment, lymph node, and margin status. Ascites was defined as computed tomography-detected fluid in the pelvic/peritoneal cavity. Overall survival was compared between groups via Cox proportional hazards models with a gamma frailty term to account for the correlation between matched pairs on entire cohort and by disease stages for subgroup analysis. RESULTS:The 154 matched cases included 24 resectable, 19 borderline resectable, 51 locally advanced, and 60 metastatic disease. Patients with ascites had higher risk of death compared with those without (conditional hazard ratio, 1.58; 95% confidence interval, 1.23-2.03; P < 0.001). Stratified analysis showed a significant association between ascites and poor prognosis in patients with localized disease (conditional hazard ratio, 1.62; 95% confidence interval, 1.18-2.24; P = 0.003). CONCLUSIONS:Radiographic ascites is a poor prognostic factor in PDAC. Our findings may aid physicians in considering systemic therapy prior to attempting local treatments.

Current evidence cannot support denying metastasectomy in otherwise resectable patients solely based on their overall KRAS or BRAF mutational status. The combination of KRAS or BRAF mutational status with certain clinicopathologic characteristics has defined groups of patients who may not derive benefit from metastasectomy, but external validation is needed. The effect of certain KRAS or BRAF variants on survival may be more pronounced and therefore future studies should consider them for surgical selection.

Background and objectives/UNASSIGNED:Sarcomas represent a heterogeneous group of tumors, and there is lack of data describing contemporary changes in patterns of care. We evaluated the epidemiology of sarcomas over 12 recent years. Methods/UNASSIGNED:The Surveillance, Epidemiology and End Results (SEER) database was queried for sarcoma cases from 2002-2014. Patient, tumor and treatment factors, and trends over time were studied overall and by subtype. Univariable and multivariable logistic regression models and 5-year survival and cause-specific mortality (CSM) were summarized. Results/UNASSIGNED:There were 78,527 cases of sarcomas with an overall incidence of 7.1 cases per 100,000 people, increasing from 6.8 in 2002 to 7.7 in 2014. Sarcoma NOS(14.8%) and soft tissue(43.4%) were the most common histology and primary site, respectively. A majority of tumors were high-grade(33.6%) and >5 cm(51.3%). CSM was 28.6% and 5-year survival was 71.4%. Many patients had unknown-grade(42.2%), which associated with 2.6 times increased odds of no surgical intervention. Conclusions/UNASSIGNED:This comprehensive national study highlights important trends including increasing incidence, changing histologic types, and underestimation of true incidence. A large proportion of sarcomas are inadequately staged (unknown-grade 42.2%) with lack of appropriate surgical treatment. Our study highlights need for standardization of care for sarcomas.

Intraductal papillary mucinous neoplasms (IPMNs) are precursors to pancreatic cancer; however, little is known about genetic heterogeneity in these lesions. The objective of this study was to characterize genetic heterogeneity in IPMNs at the single-cell level. We isolated single cells from fresh tissue from ten IPMNs, followed by whole genome amplification and targeted next-generation sequencing of pancreatic driver genes. We then determined single-cell genotypes using a novel multi-sample mutation calling algorithm. Our analyses revealed that different mutations in the same driver gene frequently occur in the same IPMN. Two IPMNs had multiple mutations in the initiating driver gene KRAS that occurred in unique tumor clones, suggesting the possibility of polyclonal origin or an unidentified initiating event preceding this critical mutation. Multiple mutations in later-occurring driver genes were also common and were frequently localized to unique tumor clones, raising the possibility of convergent evolution of these genetic events in pancreatic tumorigenesis. Single-cell sequencing of IPMNs demonstrated genetic heterogeneity with respect to early and late occurring driver gene mutations, suggesting a more complex pattern of tumor evolution than previously appreciated in these lesions. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

BACKGROUND:Intraductal papillary mucinous neoplasms (IPMNs) are precursor lesions to the development of pancreatic adenocarcinoma. We determined if non-O blood groups are more common in patients with IPMN and if blood group is a risk factor for progression to invasive pancreatic cancer among patients with IPMN. METHODS:The medical records were reviewed of all patients undergoing resection of an IPMN at Johns Hopkins Hospital from June 1997 to August 2016. Potential risk factors of high-grade dysplasia and associated adenocarcinoma were identified through a multivariate logistic regression model. RESULTS:Seven hundred and seventy-seven patients underwent surgical resection of an IPMN in which preoperative blood type was known. Sixty-two percent of IPMN patients had non-O blood groups (vs. 57% in two large US reference cohorts, P = 0.002). The association between non-O blood group was significant for patients with IPMN with low- or intermediate-grade dysplasia (P < 0.001), not for those with high-grade dysplasia (P = 0.68). Low- and intermediate-grade IPMNs were more likely to have non-type O blood compared to those with high-grade IPMN and/or associated invasive adenocarcinoma (P = 0.045). Blood type O was an independent predictor of having high-grade dysplasia without associated adenocarcinoma (P = 0.02), but not having associated invasive cancer (P = 0.72). The main risk factor for progression to invasive cancer after surgical resection was IPMN with high-grade dysplasia (P = 0.002). CONCLUSION:IPMN patients are more likely to have non-O blood groups than controls, but type O blood group carriers had higher odds of having high-grade dysplasia in their IPMN. These results indicate blood group status may have different effects on the risk and progression of IPMNs.