Jonathan L. Wong

Association of a functional IRF7 variant with systemic lupus erythematosus

OBJECTIVE A previous genome-wide association study conducted in a population of European ancestry identified rs4963128, a KIAA1542 single-nucleotide polymorphism (SNP) 23 kb telomeric to IRF7 (the gene for interferon regulatory factor 7 [IRF-7]), to be strongly associated with systemic lupus erythematosus (SLE). This study was undertaken to investigate whether genetic polymorphism within IRF7 is a risk factor for the development of SLE. METHODS We genotyped one KIAA1542 SNP (rs4963128) and one IRF7 SNP (rs1131665 [Q412R]) in an Asian population (1,302 cases, 1,479 controls), to assess their association with SLE. Subsequently, rs1131665 was further genotyped in independent panels of Chinese subjects (528 cases, 527 controls), European American subjects (446 cases, 461 controls), and African American subjects (159 cases, 115 controls) by TaqMan genotyping assay, to seek confirmation of association in various ethnic groups. A luciferase reporter assay was used to assess the effect of Q412R polymorphism on the activation of IRF-7. RESULTS Consistent association of rs1131665 (Q412R) with SLE was identified in Asian, European American, and African American populations (total 2,435 cases and 2,582 controls) (P(meta) = 6.18 × 10(-6) , odds ratio 1.42 [95% confidence interval 1.22-1.65]). Expression of the IRF7 412Q risk allele resulted in a 2-fold increase in interferon-stimulated response element transcriptional activity compared with expression of IRF7 412R (P = 0.0003), suggesting that IRF7 412Q confers elevated IRF-7 activity and may therefore affect a downstream interferon pathway. CONCLUSION These findings show that the major allele of a nonsynonymous SNP, rs1131665 (412Q) in IRF7, confers elevated activation of IRF-7 and predisposes to the development of SLE in multiple ethnic groups. This result provides direct genetic evidence that IRF7 may be a risk gene for human SLE.

Endoscopically Acquired Pancreatic Cyst Fluid MicroRNA 21 and 221 Are Associated With Invasive Cancer

OBJECTIVES:Pancreatic cysts are a group of lesions with heterogeneous malignant potential. Currently, there are no reliable biomarkers to aid in cyst diagnosis and classification. The objective of this study was to identify potential microRNA (miR) biomarkers in endoscopically acquired pancreatic cyst fluid that could be used to distinguish between benign, premalignant, and malignant cysts.METHODS:A list of candidate miRs was developed using a whole-genome expression array analysis of pancreatic cancer (pancreatic ductal adenocarcinoma) and nonmalignant samples overlapped with existing literature and predicted gene targets. Endoscopically acquired pancreatic cyst fluid samples were obtained from a group of 38 patients who underwent cyst fluid aspiration and surgical resection. Selected miR expression levels in cyst fluid samples were assessed by quantitative real-time-PCR. Additionally, in situ hybridization (ISH) on corresponding cyst tissue samples was performed to identify the source and validate the expression level of fluid miRs.RESULTS:Of the six miRs that were profiled in the study, two showed differential expression in malignant cysts. miR-221 was expressed at significantly higher levels in malignant cysts compared with benign or premalignant cysts (P=0.05). miR-21 was also expressed at significantly higher levels in malignant cysts (P<0.01). Additionally, the expression of miR-21 was significantly higher in premalignant cysts than benign cysts (P=0.03). The differential expression of miR-21 among cyst categories was confirmed by ISH.CONCLUSIONS:In this small single-center study, miRs are potential pancreatic cyst fluid diagnostic biomarkers. In particular, miR-21 is identified as a candidate biomarker to distinguish between benign, premalignant, and malignant cysts. Additionally miR-221 may be of use in the identification of more advanced malignant disease.

Age Disparity in Palliative Radiation Therapy Among Patients With Advanced Cancer

PURPOSE/OBJECTIVE Palliative radiation therapy represents an important treatment option among patients with advanced cancer, although research shows decreased use among older patients. This study evaluated age-related patterns of palliative radiation use among an elderly Medicare population. METHODS AND MATERIALS We identified 63,221 patients with metastatic lung, breast, prostate, or colorectal cancer diagnosed between 2000 and 2007 from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. Receipt of palliative radiation therapy was extracted from Medicare claims. Multivariate Poisson regression analysis determined residual age-related disparity in the receipt of palliative radiation therapy after controlling for confounding covariates including age-related differences in patient and demographic covariates, length of life, and patient preferences for aggressive cancer therapy. RESULTS The use of radiation decreased steadily with increasing patient age. Forty-two percent of patients aged 66 to 69 received palliative radiation therapy. Rates of palliative radiation decreased to 38%, 32%, 24%, and 14% among patients aged 70 to 74, 75 to 79, 80 to 84, and over 85, respectively. Multivariate analysis found that confounding covariates attenuated these findings, although the decreased relative rate of palliative radiation therapy among the elderly remained clinically and statistically significant. On multivariate analysis, compared to patients 66 to 69 years old, those aged 70 to 74, 75 to 79, 80 to 84, and over 85 had a 7%, 15%, 25%, and 44% decreased rate of receiving palliative radiation, respectively (all P<.0001). CONCLUSIONS Age disparity with palliative radiation therapy exists among older cancer patients. Further research should strive to identify barriers to palliative radiation among the elderly, and extra effort should be made to give older patients the opportunity to receive this quality of life-enhancing treatment at the end of life.

Cytidine deaminase single-nucleotide polymorphism is predictive of toxicity from gemcitabine in patients with pancreatic cancer: RTOG 9704

The aim of this study is to validate the prognostic and predictive value of the non-synonymous cytidine deaminase (CDA) Lys27Gln polymorphism for hematological toxicity and survival using a randomized phase III adjuvant trial (Radiation Therapy Oncology Group (RTOG) 9704) in pancreatic cancer in which one treatment arm received gemcitabine. CDA is involved in gemcitabine inactivation, and there is conflicting data on the role of the non-synonymous CDA Lys27Gln polymorphism in predicting toxicity and survival in cancer patients treated with gemcitabine. RTOG 9704 randomized 538 patients after pancreatic resection to receive radiotherapy with either 5-fluorouracil (5-FU) or gemcitabine. CDA Lys27Gln polymorphism genotype was analyzed. We tested an association between CDA single-nucleotide polymorphism genotype and the survival outcome by the Cox proportional hazard model adjusting for other covariates, as well as toxicity by the logistic regression model. There is statistically significant more severe hematological toxicity in patients treated with gemcitabine with either the homozygote wild-type genotype (Lys/Lys) alone (odds ratio (OR)=0.06, P=0.01), or in combination with the heterozygote (Lys/Gln; OR=0.14, P=0.03) when compared with homozygote variant genotype (Gln/Gln) when adjusted for other covariates. This was not seen in the non-gemcitabine treated arm. There are no genotype differences with respect to survival outcome. In conclusion, in this prospective randomized adjuvant study of patients with pancreatic cancer, the CDA Lys27Gln polymorphism is validated as a predictive marker of gemcitabine hematological toxicity, but not with treatment response or survival.

Precision Medicine and Pancreatic Cancer

Objectives There is a need for validated predictive markers of gemcitabine response to guide precision medicine treatment in pancreatic cancer. We previously validated human equilibrative nucleoside transporter 1 as a predictive marker of gemcitabine treatment response using Radiation Therapy Oncology Group 9704. Controversy exists about the predictive value of gemcitabine metabolism pathway biomarkers: deoxycytidine kinase (DCK), ribonucleotide reductase 1 (RRM1), RRM2, and p53R2. Methods Radiation Therapy Oncology Group 9704 prospectively randomized 538 patients after pancreatic resection to receive either 5-fluorouracil or gemcitabine. Tumor DCK, RRM1, RRM2, and p53R protein expressions were analyzed using a tissue microarray and immunohistochemistry and correlated with treatment outcome (overall survival and disease-free survival) by unconditional logistic regression analysis. Results There were 229 patients eligible for analysis from both the 5-fluorouracil and gemcitabine arms. Only RRM2 protein expression, and not DCK, RRM1, or p53R2 protein expression, was associated with survival in the gemcitabine treatment arm. Conclusions Despite limited data from other nonrandomized treatment data, our data do not support the predictive value of DCK, RRM1, or p53R2. Efforts should focus on human equilibrative nucleoside transporter 1 and possibly RRM2 as valid predictive markers of the treatment response of gemcitabine in pancreatic cancer.

Cardiovascular complications of severe acute respiratory syndrome

Background and Aims: Severe acute respiratory syndrome (SARS) is a virulent viral infection that affects a number of organs and systems. This study examined if SARS may result in cardiovascular complications. Methods and Results: 121 patients (37.5 (SD13.2) years, 36% male) diagnosed to have SARS were assessed continuously for blood pressure, pulse, and temperature during their stay in hopsital. Hypotension occurred in 61 (50.4%) patients in hospital, and was found in 28.1%, 21.5%, and 14.8% of patients during the first, second, and third week, respectively. Only one patient who had transient echocardiographic evidence of impaired left ventricular systolic function required temporary inotropic support. Tachycardia was present in 87 (71.9%) patients, and was found in 62.8%, 45.4%, and 35.5% of patients from the first to third week. It occurred independent of hypotension, and could not be explained by the presence of fever. Tachycardia was also present in 38.8% of patients at follow up. Bradycardia only occurred in 18 (14.9%) patients as a transient event. Reversible cardiomegaly was reported in 13 (10.7%) patients, but without clinical evidence of heart failure. Transient atrial fibrillation was present in one patient. Corticosteroid therapy was weakly associated with tachycardia during the second (χ2 = 3.99, p = 0.046) and third week (χ2 = 6.53, p = 0.01), although it could not explain tachycardia during follow up. Conclusions: In patients with SARS, cardiovascular complications including hypotension and tachycardia were common but usually self limiting. Bradycardia and cardiomegaly were less common, while cardiac arrhythmia was rare. However, only tachycardia persisted even when corticosteroid therapy was withdrawn.

Tu1468 Evaluation of International Consensus Diagnostic Criteria in the Diagnosis of Autoimmune Pancreatitis: A Single Center North American Cohort Study

Context In 2011, an international symposium on Autoimmune Pancreatitis produced the International Consensus Diagnostic Criteria, which can be used to stratify patients with autoimmune pancreatitis as having type 1, type 2, or autoimmune pancreatitis – not otherwise specified. There are few studies examining the application of International Consensus Diagnostic Criteria to a cohort of North American patients with autoimmune pancreatitis. Objectives To apply International Consensus Diagnostic Criteria to a cohort of 51 patients with autoimmune pancreatitis followed at a North American medical center. To compare International Consensus Diagnostic Criteria with other guidelines with emphasis on patients who were unclassifiable using International Consensus Diagnostic Criteria. Design We applied International Consensus Diagnostic Criteria using clinical-radiological-pathological features. We reevaluated patients who were unclassifiable per ICDC with Japanese Pancreatic Society-2006, HISORt, Korean, Asian, and JPS-2011 guidelines. We statistically compared type 1, type 2, and unclassifiable patients based on demographic and clinical presentation. T-test and chi-square analysis was used for statistical analysis. Results 37 patients were categorized as definitive type 1 or type 2 autoimmune pancreatitis, 1 patient as probable type 1 autoimmune pancreatitis, and 13 were unclassifiable. Unclassifiable patients had indeterminate/atypical parenchymal imaging or none at all, and 6 patients had elevated serology. Diagnostic endoscopic retrograde cholangio-pancreatography was performed on 6 patients and 1 patient had persistent waxing and waning of clinical and radiologic features. 6 patients could be diagnosed with autoimmune pancreatitis using JPS-2006, Korean, or Asian Criteria, and 4 patients using either HISORt or JPS-2011. There was no statistically significant difference between classifiable and unclassifiable patients based on demographics or clinical presentation. Conclusions The ICDC’s dependence on histology, diagnostic endoscopic retrograde cholangio-pancreatography, and lack of acknowledgment of waxing-waning features limits applicability. Our cohort evolved during routine practice and we identify discrepancies amongst guidelines.

Tu1514 Limited Application of New International Consensus Diagnostic Criteria for Autoimmune Pancreatitis in Clinical Practice

G A A b st ra ct s of patients with surgical pathology as the gold standard for outcome. Design: 137 patients underwent diagnostic analysis of EUS aspirated pancreatic cyst fluid. DNA was extracted from cyst fluid with quantity and quality (extent of degradation) measured by optical density and qPCR. Mutational analysis targeted KRAS point mutation and loss of heterogeneity (LOH) mutations of 16 markers at 1p, 3p, 5q, 9p, 10q, 17p, 17q, 18q, 21q, 22q. Molecular findings were integrated with results from EUS, chemistry and cytology. For each marker, presence or absence of mutation and clonality were determined, determined, with high clonality comprising 75% of more of cells affected by LOH and low clonality comprising 50-75% of cells. Interpretation of combined molecular, imaging, and chemistry results were classified and subsequently compared to surgical outcome or followup. Surgical pathology was classified into indolent biological behavior (benign or low grade disease), and aggressive biological behavior (high grade or malignant disease). Results: Surgical pathology was available on 81 of these patients. Outcomes included benign cystic neoplasms with low and high grade dysplasia, malignant ductal disease, endocrine neoplasms and pseudocysts. There were 32 aggressive outcomes and 49 indolent outcomes. Molecular findings, including elevated DNA level, and high numbers and clonality of mutations, correlated strongly with aggressive biological behavior. While KRAS mutation was highly specific for mucinous cyst formation, individual molecular parameters used in isolation showed limited sensitivity for detection of aggressive disease. Combining all molecular parameters together, sensitivity was 94%, and specificity was 100%, with overall accuracy of 97%. Conclusions: The molecular biology of pancreatic cystic disease involves multiple pathways that can each lead to cancer. The majority of pancreatic cysts do not progress to cancer and the diagnosis and biological potential of individual lesions can be effectively characterized by integrating broad panel molecular findings with information from first line testing. The presence or absence of aggressive molecular changes, taken in the context of overall findings provides an effective means to individualize patient management when first line results are unclear.

559 Predictive Markers of Gemcitabine Treatment Response in Pancreas Cancer: A Pharmacogenomic Pathway Approach

Background: The development of effective non-Gemcitabine based treatment options for pancreatic cancer (e.g. FOLFIRONOX) opens the door for the clinical need for predictive markers of Gemcitabine response to assist in treatment selection. Our group previously validated hENT1, a Gemcitabine membrane transporter, as a predictive marker of Gemcitabine treatment response using RTOG 9704. Controversy exists about the predictive value of other components of the Gemcitabine metabolism pathway: DCK, RRM1, RRM2 and p53R2. We used the RTOG 9704 data set to evaluate the potential predictive value for Gemcitabine response of these markers. Methods: RTOG 9704 prospectively randomized 538 patients after pancreatic resection to receive either 5-FU or Gemcitabine. Tumor DCK, RRM1, RRM2, and p53R2 protein expression was analyzed in patients from this study using a Tissue Microarray (TMA) and IHC. Overall survival (OS) and disease-free survival (DFS) were estimated univariately with the Kaplan-Meier method and multivariate Cox proportional hazards models were used to determine if deoxycytidine kinase (DCK), ribonucleotide reductase M1 (RRM1), ribonucleotide reductase M2 (RRM2), and p53R2 protein levels correlated with OS and DFS. Results: 203 patients were eligible for analysis from both the 5-FU and Gemcitabine arm. DCK, RRM1, RRM2 and p53R2 protein expression was not associated with OS or DFS in the Gemcitabine treatment arm (Table 1). RRM1 and DCK expression did appear to be associated with OS in the entire treatment group and the 5FU treatment group, but not the Gemcitabine treatment arm. Conclusion: Despite limited data from nonrandomized treatment data suggesting a possible predictive role for DCK or RRM1 for determining response to Gemcitabine, our data from this prospective randomized treatment trial, which included a Gemcitabine alone arm, does not support the predictive value of DCK, RRM1, RRM2 or p53R2 in determining response to Gemcitabine. Efforts should focus on hENT1 as a valid predictive marker of treatment response of Gemcitabine in pancreas cancer. This project was supported by RTOG grant U10 CA21661, RTOG BsR grant U24 CA114734, and CCOP grant U10 CA37422 from the National Cancer Institute (NCI) and by the RTOG Translational Research Program. Overall Survival for all patients, Gemcitabine Treatment Arm and 5-FU Treatment Arm. Univariate Hazard Ratios (p-value)