OverviewPancreatic cancer is one of the most common causes of cancer-related death among men and women in the United States. Abstract Ductal adenocarcinoma and its variants account for most pancreatic malignancies. High-quality multiphase imaging can help to preoperatively distinguish between patients eligible for resection with curative intent and those with unresectable disease. Systemic therapy is used in the neoadjuvant or adjuvant pancreatic cancer setting, as well as in the management of locally advanced unresectable and metastatic disease. Clinical trials are critical for making progress in treatment of pancreatic cancer. The NCCN Guidelines for Pancreatic Adenocarcinoma focus on diagnosis and treatment with systemic therapy, radiation therapy, and surgical resection. J Natl Compr Canc Netw 2017;15(8):1028-1061 doi: 10.6004/jnccn.2017 NCCN Categories of Evidence and Consensus Please NoteThe These guidelines are also available on the Internet. For the latest update, visit NCCN.org.
Single-agent immunotherapy has achieved limited clinical benefit to date in patients suffering from pancreatic ductal adenocarcinoma (PDAC). This may be due to the presence of a uniquely immunosuppressive tumor microenvironment (TME). Critical obstacles to immunotherapy in PDAC tumors include a high number of tumor-associated immunosuppressive cells and a uniquely desmoplastic stroma that acts as a barrier to T-cell infiltration. We have identified hyperactivated focal adhesion kinase (FAK) activity in neoplastic PDAC cells as a significant regulator of the fibrotic and immunosuppressive TME. We found that FAK activity was elevated in human PDAC tissues and correlates with high levels of fibrosis and poor CD8+ cytotoxic T-cell infiltration. Single-agent FAK inhibition using the selective FAK inhibitor VS-4718 significantly limited tumor progression, resulting in a doubling of survival in the p48-Cre/LSL-KrasG12D/p53Flox/+ (KPC) mouse model of human PDAC. This delay in tumor progression was associated with dramatically reduced tumor fibrosis, and decreased numbers of tumor-infiltrating immunosuppressive cells. We also found that FAK inhibition rendered the previously unresponsive KPC mouse model responsive to T cell immunotherapy and PD-1 antagonists. These data suggest that FAK inhibition increases immune surveillance by overcoming the fibrotic and immunosuppressive PDAC TME and renders tumors responsive to immunotherapy.
SUMMARY Tumor-associated macrophages (TAMs) are essential components of the cancer microenvironment and play critical roles in the regulation of tumor progression. Optimal therapeutic intervention requires in-depth understanding of the sources that sustain macrophages in malignant tissues. In this study, we investigated the ontogeny of TAMs in murine pancreatic ductal adenocarcinoma (PDAC) models. We identified both inflammatory monocytes and tissue-resident macrophages as sources of TAMs. Unexpectedly, significant portions of pancreas-resident macrophages originated from embryonic development and expanded through in situ proliferation during tumor progression. Whereas monocyte-derived TAMs played more potent roles in antigen presentation, embryonically derived TAMs exhibited a pro-fibrotic transcriptional profile, indicative of their role in producing and remodeling extracellular matrix molecules. Collectively, these findings uncover the heterogeneity of TAM origin and functions, and could provide therapeutic insight for PDAC treatment.
Pancreatic cancer is the fourth leading cause of cancer-related death among men and women in the United States. A major challenge in treatment remains patients’ advanced disease at diagnosis. The NCCN Guidelines for Pancreatic Adenocarcinoma provides recommendations for the diagnosis, evaluation, treatment, and follow-up for patients with pancreatic cancer. Although survival rates remain relatively unchanged, newer modalities of treatment, including targeted therapies, provide hope for improving patient outcomes. Sections of the manuscript have been updated to be concordant with the most recent update to the guidelines. This manuscript focuses on the available systemic therapy approaches, specifically the treatment options for locally advanced and metastatic disease.
Background Pancreatic ductal adenocarcinoma utilizes the CCL2/CCR2 chemokine axis to facilitate recruitment of tumor associated macrophages to sculpt an immunosuppressive tumor microenvironment. This pathway has prognostic implications in pancreas cancer, and blockade of CCR2 restores anti-tumor immunity in pre-clinical models. This provided the rationale for a clinical study in pancreatic adenocarcinoma to determine the safety and recommended phase 2 oral dosage of the CCR2 inhibitor PF-04136309 in combination with chemotherapy (FOLFIRINOX). Methods In this single-center, open label, phase Ib clinical trial patients age ≥ 18 years with treatment naïve borderline resectable or locally advanced, biopsy-proven pancreatic ductal adenocarcinoma, Eastern Cooperative Oncology Group performance status <2, measurable disease by Response Evaluation Criteria in Solid Tumors Version 1.1, and normal end organ function were eligible for enrollment. FOLFIRINOX (oxaliplatin, 85 mg/m2; irinotecan, 180 mg/m2; leucovorin, 400 mg/m2, and bolus fluorouracil 400 mg/m2 followed by 2,400 mg/m2 46 hour continuous infusion) was administered every 2 weeks for a total of six treatment cycles. To determine the recommended phase 2 dose, PF-04136309 was orally administered at a starting dose of 500 mg twice daily in a standard 3+3 dose de-escalation design with an expansion phase planned at the recommended phase 2 dose. Both FOLFIRINOX and PF-04136309 were simultaneously initiated with a total treatment duration of 3 months. The primary endpoints were to determine the recommended phase 2 dose and toxicity of PF-04136309 in combination with FOLFIRINOX. All patients in the dose de-escalation and expansion phase received the recommended phase 2 dose of PF-04136309 were combined for assessment of treatment toxicity by an intention to treat analysis. For tissue specimen comparison in corollary studies, a group of patients receiving FOLFIRINOX alone were enrolled and evaluated for treatment related toxicity. This study has been completed and is registered at ClinicalTrials.gov; number NCT01413022. Results From April 19th, 2012 through November 12th, 2014 a total of 47 patients were enrolled. The dose de-escalation group (n=6) received PF-04136309 at 500 mg administered orally twice daily. No dose-limiting toxicities were observed and this was established as the recommended phase 2 dose. The expansion phase cohort (n=33) and patients in the dose de-escalation arm receiving PF-04136309 at the recommended phase 2 dose (n=6) were combined for assessment of treatment related toxicity. No therapy related deaths occurring during the study interval. Early termination as the result of treatment related toxicity occurred in 2 of the 39 patients (5%) in the FOLFIRINOX plus PF-04136309 arm. Grade ≥3 adverse events reported in ≥10% of the patients receiving PF-04136309 included neutropenia in 27 patients (69%), febrile neutropenia in 7 patients (18%), lymphopenia in 4 patients (10%), diarrhea in 6 patients (15%), and hypokalemia in 7 patients (18%). Among...
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