ACR Appropriateness Criteria® Resectable Pancreatic Cancer

Fisetin inhibits proliferation of pancreatic adenocarcinoma by inducing DNA damage via RFXAP/KDM4A-dependent histone H3K36 demethylation

Pancreatic adenocarcinoma (PDAC) is an extremely malignant tumor that is associated with low survival rates. Fisetin is a natural flavonoid that shows diverse antitumor effects, including DNA damage, in various cancers. Increasing studies have demonstrated that epigenetic modifications play critical roles in DNA-damage response. However, the epigenetic regulation mechanism of fisetin in cancers is hardly studied. RFXAP is a critical transcription factor for MHC II molecules, however, its transcriptional role in PDAC is poorly understood. The anti-PDAC effect of fisetin was measured by CCK-8, flow cytometry, xenograft tumor nude mice model. DNA-damage levels were examined by immunofluorescence. Bioinformatics analysis was used to examine the expression of RFXAP and other genes involved in DNA-damage response. ChIP sequencing was used to explore the transcriptional role of RFXAP. The expression of target gene KDM4A was measured by qRT-PCR and western blots. KDM4A promoter activity was analyzed using dual-luciferase reporter assay. RFXAP overexpressing or silencing of PDAC cells was used to explore the effect of RFXAP in DNA damage induced by fisetin. We found that fisetin inhibited cell proliferation and induced DNA damage and S-phase arrest in PDAC. Expression of RFXAP and other DNA-damage response genes were upregulated by fisetin. We revealed that RFXAP expression was relatively low in PDAC and correlated with tumor stage and poor prognosis. Then we explored the transcriptional role of RFXAP and found that RFXAP targeted KDM4A, a special demethylase specific for tri- and dimethylated histone H3K36. We found that overexpression of RFXAP upregulated KDM4A and attenuated methylation of H3K36, thereby impairing DNA repair and enhancing the DNA damage induced by fisetin, while RFXAP silencing showed the opposite effect. We also found the function of fisetin in enhancing the effect of chemotherapy on pancreatic cancer cells. Our findings revealed that fisetin induced DNA damage via RFXAP/KDM4A-dependent histone H3K36 demethylation, thus causing inhibition of proliferation in PDAC.

Estimating Recurrence after Upfront Surgery in Patients with Resectable Pancreatic Ductal Adenocarcinoma by Using Pancreatic CT: Development and Validation of a Risk Score

Background No preoperative model is available for predicting postsurgical prognosis of patients with resectable pancreatic ductal adenocarcinoma (PDAC). Purpose To develop and validate a preoperative risk scoring system using clinical and CT variables to predict recurrence-free survival (RFS) after upfront surgery in patients with resectable PDAC. Materials and Methods In this retrospective study, consecutive patients with resectable PDAC underwent upfront surgery from January 2014 to December 2015 (development set) and from January 2016 to January 2017 (test set). In the development set, multivariable Cox proportional hazard modeling with bootstrapping was used to select clinical and CT variables associated with RFS and to construct a risk scoring system. The discrimination capability of the risk score was assessed by using the Harrell C-index and compared with that of pathologic American Joint Committee on Cancer tumor stage. The risk score was validated in the test set. Results A total of 395 patients were evaluated, including 262 patients (mean age ± standard deviation, 64 years ± 10; 155 men) in the development set and 133 (mean age, 64 years ± 9; 79 men) in the test set. Five independent variables predicted risk of recurrence or death: tumor size (hazard ratio [HR], 1.23; 95% confidence interval [CI]: 1.05, 1.44; P = .009), hypodense tumor in the portal venous phase (HR, 1.66; 95% CI: 1.01, 2.73; P = .04), tumor necrosis (HR, 2.04; 95% CI: 1.38, 3.03; P < .001), peripancreatic tumor infiltration (HR, 1.50; 95% CI: 1.07, 2.11; P = .02), and suspicious metastatic lymph nodes (HR, 1.94; 95% CI: 1.38, 2.72; P < .001). In the test set, the risk score showed good discrimination capability (C-index of 0.68; 95% CI: 0.63, 0.74) and outperformed the pathologic tumor stage (C-index of 0.60; 95% CI: 0.55, 0.66; P = .03). Patients were categorized into favorable, intermediate, and poor prognosis groups with 1-year RFS of 0.87, 0.58, and 0.26, respectively. Conclusion The presented preoperative risk score can predict recurrence-free survival after upfront surgery in patients with resectable pancreatic ductal adenocarcinoma. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Pandharipande and Anderson in this issue.

Host IDO2 Gene Status Influences Tumor Progression and Radiotherapy Response in KRAS-Driven Sporadic Pancreatic Cancers

PURPOSE

Heritable genetic variations can affect the inflammatory tumor microenvironment, which can ultimately affect cancer susceptibility and clinical outcomes. Recent evidence indicates that IDO2, a positive modifier in inflammatory disease models, is frequently upregulated in pancreatic ductal adenocarcinoma (PDAC). A unique feature of IDO2 in humans is the high prevalence of two inactivating single-nucleotide polymorphisms (SNP), which affords the opportunity to carry out loss-of-function studies directly in humans. In this study, we sought to address whether genetic loss of IDO2 may influence PDAC development and responsiveness to treatment.Experimental Design: Transgenic Ido2 ^+/+ and Ido2 ^-/- mice in which oncogenic KRAS is activated in pancreatic epithelial cells were evaluated for PDAC. Two patient data sets (N = 200) were evaluated for the two IDO2-inactivating SNPs together with histologic, RNA expression, and clinical survival data.

RESULTS

PDAC development was notably decreased in the Ido2 ^-/- mice (30% vs. 10%, P < 0.05), with a female predominance similar to the association observed for one of the human SNPs. In patients, the biallelic occurrence of either of the two IDO2-inactivating SNPs was significantly associated with markedly improved disease-free survival in response to adjuvant radiotherapy (P < 0.01), a treatment modality that has been highly debated due to its variable efficacy.

CONCLUSIONS

The results of this study provide genetic support for IDO2 as a contributing factor in PDAC development and argue that IDO2 genotype analysis has the immediate potential to influence the PDAC care decision-making process through stratification of those patients who stand to benefit from adjuvant radiotherapy.

Does adjuvant radiation provide any survival benefit after an R1 resections for pancreatic cancer?

BACKGROUND

The benefit of adding external beam radiation to adjuvant chemotherapy in patients that have undergone a margin positive resection for early stage, pancreatic ductal adenocarcinoma has not been determined definitively.

METHODS

The National Cancer Data Base was queried to evaluate the utility of adjuvant radiation in patients with pathologic stage I-II pancreatic ductal adenocarcinoma who underwent upfront pancreatoduodenectomy with a positive margin (margin positive resection) between 2004 and 2013.

RESULTS

In the study, 1,392 patients met inclusion criteria, of whom 263 (18.9%) were lymph node-negative (pathologic stages IA, IB, IIA) and 1,129 (81.1%) were node-positive (pathologic stage IIB); 938 (67.4%) patients received adjuvant radiation and chemotherapy, while 454 (32.6%) received adjuvant chemotherapy alone. Cox modeling stratified by nodal status demonstrated the benefit of radiation to be statistically significant only in node positive patients (hazard ratio 0.81, 95% confidence interval, 0.71-0.93). Node-positive patients receiving adjuvant radiation and chemotherapy had an adjusted median survival of 17.5 months vs 15.2 months for those receiving adjuvant chemotherapy alone (P=.003). In patients who had negative nodes, there was no difference in overall survival with radiation (22.5 vs 23.6 months, P=.511).

CONCLUSION

Addition of radiation to adjuvant chemotherapy after a margin positive resection confers a survival benefit albeit limited (about 2 months) in patients with node-positive pancreatic head cancer. (Surgery 2017;160:XXX-XXX.).