Bilateral orchiectomy or luteinizing hormone-releasing hormone agonists are recommended initial androgen-deprivation treatments (ADTs). Nonsteroidal antiandrogen monotherapy merits discussion as an alternative; steroidal antiandrogen monotherapy should not be offered. Combined androgen blockade should be considered. In metastatic or progressive PCa, immediate versus symptom-onset institution of ADT results in a moderate decrease (17%) in relative risk (RR) for PCa-specific mortality, a moderate increase (15%) in RR for non-PCa-specific mortality, and no overall survival advantage. Therefore, the Panel cannot make a strong recommendation for early ADT initiation. Prostate-specific antigen (PSA) kinetics and other metrics allow identification of populations at high risk for PCa-specific and overall mortality. Further studies must be completed to assess whether patients with adverse prognostic factors gain a survival advantage from immediate ADT. For patients electing to wait until symptoms for ADT, regular monitoring visits are indicated. For patients with recurrence, clinical trials should be considered if available. Currently, data are insufficient to support use of intermittent androgen blockade outside clinical trials
High-dose hypofractionated proton therapy demonstrated high LC rates for HCC and ICC safely, supporting ongoing phase III trials of radiation in HCC and ICC.
Purpose
Local tumor growth is a major cause of morbidity and mortality in nearly 30% of patients with pancreatic ductal adenocarcinoma (PDAC). Radiotherapy (RT) is commonly used for local disease control in PDAC, but efficacy is limited. We studied the impact of selectively intervening on RT-induced inflammation as an approach to overcome resistance to RT in PDAC.
Experimental Design
PDAC cell lines derived from primary pancreatic tumors arising spontaneously in KrasLSL-G12D/+;Trp53LSL-R172H/+;Pdx-1 Cre (KPC) mice were implanted into syngeneic mice and tumors were focally irradiated using the Small Animal Radiation Research Platform (SARRP). We determined the impact of depleting T cells and Ly6C+ monocytes as well as inhibiting the chemokine CCL2 on RT efficacy. Tumors were analyzed by flow cytometry and immunohistochemistry to detect changes in leukocyte infiltration, tumor viability and vascularity. Assays were performed on tumor tissues to detect cytokines and gene expression.
Results
Ablative RT alone had minimal impact on PDAC growth but led to a significant increase in CCL2 production by tumor cells and recruitment of Ly6C+CCR2+ monocytes. A neutralizing anti-CCL2 antibody selectively inhibited RT-dependent recruitment of monocytes/macrophages and delayed tumor growth but only in combination with RT (p<0.001). This anti-tumor effect was associated with decreased tumor proliferation and vascularity. Genetic deletion of CCL2 in PDAC cells also improved RT efficacy.
Conclusions
PDAC responds to RT by producing CCL2, which recruits Ly6C+CCR2+ monocytes to support tumor proliferation and neovascularization after RT. Disrupting the CCL2-CCR2 axis in combination with RT holds promise for improving RT efficacy in PDAC.
The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Pancreatic Adenocarcinoma discuss the workup and management of tumors of the exocrine pancreas. These NCCN Guidelines Insights provide a summary and explanation of major changes to the 2012 NCCN Guidelines for Pancreatic Adenocarcinoma. The panel made 3 significant updates to the guidelines: 1) more detail was added regarding multiphase CT techniques for diagnosis and staging of pancreatic cancer, and pancreas protocol MRI was added as an emerging alternative to CT; 2) the use of a fluoropyrimidine plus oxaliplatin (e.g., 5-FU/leucovorin/oxaliplatin or capecitabine/oxaliplatin) was added as an acceptable chemotherapy combination for patients with advanced or metastatic disease and good performance status as a category 2B recommendation; and 3) the panel developed new recommendations concerning surgical technique and pathologic analysis and reporting.
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