Longer Course of Induction Chemotherapy Followed by Chemoradiation Favors Better Survival Outcomes for Patients With Locally Advanced Pancreatic Cancer.

OBJECTIVES: At diagnosis, 30% of patients with pancreatic cancer are unresectable stage 3 locally advanced. The standard treatment for locally advanced pancreatic cancer (LAPC) is not defined. The current study was conducted to assess the roles of chemotherapy and chemoradiation for LAPC treatment. MATERIALS AND METHODS: Between June 2006 and March 2011, 100 patients with LAPC were treated at the Johns Hopkins Hospital. Retrospective analysis was performed to compare cumulative incidence of progression (CIP) and overall survival (OS) among different subgroups. RESULTS: For the 100 patients, the median OS was 15.8 months and the median CIP was 8.4 months. The combination of chemotherapy and chemoradiation before disease progression was significantly associated with improved CIP (P=0.001) and improved OS when compared with chemoradiation alone (median OS: 16.4 vs. 11.1 mo, P=0.03). Among patients receiving combination treatment, patients who received chemotherapy first followed by chemoradiation had a trend toward lower CIP (P=0.09) and improved OS (median OS: 18.1 vs. 11.0 mo, P=0.09). Patients who received >2 cycles of chemotherapy before chemoradiation had a significantly decreased CIP (P=0.008) and a trend toward better OS (median OS: 19.4 vs. 15.7 mo, P=0.10). On multivariate analysis, receiving >2 cycles of chemotherapy before chemoradiation was associated with improved CIP. CONCLUSIONS: Although combination chemotherapy and chemoradiation is favored in the treatment of LAPC, longer induction chemotherapy may play a more important role in sensitization of tumors to subsequent chemoradiation. Our results support treating patients with induction chemotherapy for at least 3 cycles followed by consolidative chemoradiation. These results merit further validation by a prospective study.

PD-1/PD-L1 blockade together with vaccine therapy facilitates effector T-cell infiltration into pancreatic tumors.

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.

A single institution's 26-year experience with nonfunctional pancreatic neuroendocrine tumors: a validation of current staging systems and a new prognostic nomogram.

OBJECTIVE: To validate the 2010 American Joint Committee on Cancer (AJCC) and 2006 European Neuroendocrine Tumor Society (ENETS) tumor staging systems for pancreatic neuroendocrine tumors (PanNETs) using the largest, single-institution series of surgically resected patients in the literature. BACKGROUND: The natural history and prognosis of PanNETs have been poorly defined because of the rarity and heterogeneity of these neoplasms. Currently, there are 2 main staging systems for PanNETs, which can complicate comparisons of reports in the literature and thereby hinder progress against this disease. METHODS: Univariate and multivariate analyses were conducted on the prognostic factors of survival using 326 sporadic, nonfunctional, surgically resected PanNET patients who were cared for at our institution between 1984 and 2011. Current and proposed models were tested for survival prognostication validity as measured by discrimination (Harrel's c-index, HCI) and calibration. RESULTS: Five-year overall-survival rates for AJCC stages I, II, and IV are 93% (88%-99%), 74% (65%-83%), and 56% (42%-73%), respectively, whereas ENETS stages I, II, III, and IV are 97% (92%-100%), 87% (80%-95%), 73% (63%-84%), and 56% (42%-73%), respectively. Each model has an HCI of 0.68, and they are no different in their ability to predict survival. We developed a simple prognostic tool just using grade, as measured by continuous Ki-67 labeling, sex, and binary age that has an HCI of 0.74. CONCLUSIONS: Both the AJCC and ENETS staging systems are valid and indistinguishable in their survival prognostication. A new, simpler prognostic tool can be used to predict survival and decrease interinstitutional mistakes and uncertainties regarding these neoplasms.