Faculty Bibliography

BACKGROUND:Outcomes for ampullary adenocarcinomas are heterogeneous, and numerous methods of categorisation exist. A histomolecular phenotype based on histology, caudal-type homeodomain transcription factor 2 (CDX2) staining and Mucin 1 (MUC1) staining has recently been tested and validated in two cohorts. We attempt to validate this classification in a large patient population. METHODS:Tissue samples from 163 patients with resected ampullary adenocarcinoma were classified based on histology and immunohistochemical expression of CDX2 and MUC1. A pancreaticobiliary histomolecular classification (PB) was defined as a sample with pancreaticobiliary histology, positive MUC1 and negative CDX2 expression. RESULTS:There were 82 deaths; median follow-up of 32.4 months; and median overall survival of 87.7 (95% CI 42.9-109.5) months. PB comprised 28.2% of the cases. Factors associated with overall survival were histological subtype (P=0.0340); T1/2 vs T3/4 (P=0.001); perineural (P<0.0001) and lymphovascular (P=0.0203) invasion; and histomolecular intestinal histomolecular phenotype (INT) vs PB phenotype (106.4 vs 21.2 months, P<0.0001). Neither MUC1 nor CDX2 was statistically significant, although MUC1 positivity defined as ⩾10% staining was significant (P=0.0023). In multivariate analysis, age (HR 1.03), PB phenotype (HR 2.26) and perineural invasion (PNI; HR 2.26) were associated with poor survival. CONCLUSIONS:The prognostic ability of histomolecular phenotype has been validated in an independent cohort of ampullary adenocarcinoma patients.

OBJECTIVES/OBJECTIVE:Lymphopenia is a common consequence of chemoradiation therapy yet is seldom addressed clinically. This study was conducted to determine if patients with locally advanced pancreatic cancer (LAPC) treated with definitive chemoradiation develop significant lymphopenia and if this affects clinical outcomes. METHODS:A retrospective analysis of patients with LAPC treated with chemoradiation at a single institution from 1997 to 2011 was performed. Total lymphocyte counts (TLCs) were recorded at baseline and then monthly during and after chemoradiation. The correlation between treatment-induced lymphopenia, established prognostic factors, and overall survival was analyzed using univariate Cox regression analysis. Important factors identified by univariate analysis were selected as covariates to construct a multivariate proportional hazards model for survival. RESULTS:A total of 101 patients met eligibility criteria. TLCs were normal in 86% before chemoradiation. The mean reduction in TLC per patient was 50.6% (SD, 40.6%) 2 months after starting chemoradiation (P<0.00001), and 46% had TLC<500 cells/mm. Patients with TLC<500 cells/mm 2 months after starting chemoradiation had inferior median survival (8.7 vs. 13.3 mo, P=0.03) and PFS (4.9 vs. 9.0 mo, P=0.15). Multivariate analysis revealed TLC<500 cells/mm to be an independent predictor of inferior survival (HR=2.879, P=0.001) along with baseline serum albumin (HR=3.584, P=0.0002), BUN (HR=1.060, P=0.02), platelet count (HR=1.004, P=0.005), and radiation planning target volume (HR=1.003, P=0.0006). CONCLUSIONS:Severe treatment-related lymphopenia occurs frequently after chemoradiation for LAPC and is an independent predictor of inferior survival.

BACKGROUND:Pancreatic ductal adenocarcinoma (PDA) is comprised of a prominent desmoplastic stromal compartment and only 10-40% of the tumour consists of PDA cells. However, how stromal components should be assessed and how the characteristics of the stromal compartment determine clinical outcomes in PDA patients remain unknown. METHOD/METHODS:A cohort of 66 consecutive patients who underwent pancreaticoduodenectomy and were primarily followed at Johns Hopkins Hospital between 1998 and 2004, and treated with adjuvant therapy, were included in a retrospective analysis. Resected PDA blocks with good tissue preservation were available for all patients. A new, computer-aided, quantitative method was developed to assess the density and activity of stroma in PDAs and the associations of these characteristics with clinical outcomes. RESULTS:High stromal density in resected PDA was found to be significantly associated with longer disease-free [adjusted hazard ratio (aHR) 0.39; P = 0.001] and overall (aHR 0.44; P = 0.004) survival after adjusting for the use of pancreatic cancer vaccine therapy, as well as gender and resection margin positivity. Stromal activity, representing activated pancreatic stellate cells in PDAs, was not significantly associated with the prognosis of resected PDAs. CONCLUSIONS:These results illustrate the complexity of the role of stroma in PDAs. Further exploration of the prognostic ability of the characteristics of stroma is warranted.

Pancreatic ductal adenocarcinoma (PDA) has a poor prognosis due to late detection and resistance to conventional therapies. Published studies show that the PDA tumor microenvironment is predominantly infiltrated with immune suppressive cells and signals that if altered, would allow effective immunotherapy. However, single-agent checkpoint inhibitors including agents that alter immune suppressive signals in other human cancers such as cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed death 1 (PD-1), and its ligand PD-L1, have failed to demonstrate objective responses when given as single agents to PDA patients. We recently reported that inhibition of the CTLA-4 pathway when given together with a T cell inducing vaccine gives objective responses in metastatic PDA patients. In this study, we evaluated blockade of the PD-1/PD-L1 pathway. We found that PD-L1 is weakly expressed at a low frequency in untreated human and murine PDAs but treatment with a granulocyte macrophage colony-stimulating factor secreting PDA vaccine (GVAX) significantly upregulates PD-L1 membranous expression after treatment of tumor-bearing mice. In addition, combination therapy with vaccine and PD-1 antibody blockade improved murine survival compared with PD-1 antibody monotherapy or GVAX therapy alone. Furthermore, PD-1 blockade increased effector CD8 T lymphocytes and tumor-specific interferon-γ production of CD8 T cells in the tumor microenvironment. Immunosuppressive pathways, including regulatory T cells and CTLA-4 expression on T cells were overcome by the addition of vaccine and low-dose cyclophosphamide to PD-1 blockade. Collectively, our study supports combining PD-1 or PD-L1 antibody therapy with a T cell inducing agent for PDA treatment.

INTRODUCTION/BACKGROUND:Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are precursor lesions that progress to invasive cancer through progressively worsening dysplasia. Although smoking is an established risk factor for pancreatic adenocarcinoma, potential associations with IPMN grade of dysplasia remain unclear. METHODS:Pancreatic resections for IPMN from 1995 to 2013 were retrospectively reviewed. A total of 446 patients in which the smoking status was documented were identified. RESULTS:Smoking history was positive in 47% of patients. Of smokers, 50% had branch-duct, 14% had main-duct, and 36% had mixed-type IPMN. Patients with main-duct IPMN were more commonly smokers (65%), compared to smoking history in 46% with mixed and 44% with branch-duct IPMN (p = 0.03). High-grade dysplasia occurred in 25% of smokers and 21% of nonsmokers (p = 0.32), and invasive carcinoma in 25% of smokers and 25% nonsmokers (p = 0.95). On multivariate analysis, duct size was independently associated with high-grade dysplasia (OR = 3.17, 95% CI = 1.79-5.64, p < 0.001). Presence of mural nodules (OR = 3.34, 95% CI = 1.82-6.12, p < 0.001), duct size (OR = 3.87, 95% CI = 2.21-6.75, p < 0.001), and symptoms (OR = 7.10, 95% CI = 3.80-13.08, p < 0.001), but not smoking history (OR = 1.10, 95% CI = 0.64-1.88, p = 0.73), were independent predictors of invasive carcinoma. Median overall survival was 70 months for smokers and 88 months for nonsmokers (p = 0.68). CONCLUSION/CONCLUSIONS:Positive smoking history correlated with duct type classification but does not appear to be a risk factor for harboring high-grade dysplasia or invasive carcinoma in IPMNs.