The Impact of Nutritional Support on Survival Outcomes in Patients with Advanced Gastric Adenocarcinoma Treated with Chemotherapy

Malnutrition and cachexia occur commonly in patients with advanced gastric cancer (AGC). This study elucidated the effect of nutritional support (NS) on survival outcomes among patients with AGC undergoing chemotherapy. We retrospectively evaluated new AGC cases at our institute between January 2015 and January 2021. Inclusion criteria were unresectable or recurrent chemotherapy-treated gastric adenocarcinoma, ECOG performance status (PS) 0-2, and adequate organ function. Time to treatment failure (TTF) and overall survival (OS) were evaluated, and univariate and multivariate analyses identified prognostic factors. A total of 103 eligible patients were separated into groups: 69 patients (67%) into NS and 34 (33%) into routine care (RC). The median follow-up time was 11.0 mo, (0.5-92). NS was offered to patients with poorer PS (p = 0.03), Glasgow prognostic score (GPS) positivity (p = 0.001), and high neutrophil-to-lymphocyte ratios (cut-off ≤ 3, p = 0.02). Median OS and TTF in the RC and NS groups were 11.6 and 10.4 mo, (p = 0.99) and 4.2 and 5.5 mo, (p = 0.07), respectively. Multivariate analyses identified NS (hazard ratio [HR] = 0.53, p = 0.01) and GPS positivity for TTF, and low body mass index (HR = 2.03, p = 0.007) and GPS positivity (HR = 2.25, p = 0.001) for OS as significant prognostic factors. Thus, NS with chemotherapy is a potentially effective intervention for AGC.

Impact of Preoperative Occult-Bacterial Translocation on Surgical Site Infection in Patients Undergoing Pancreatoduodenectomy

BACKGROUND

Occult-bacterial translocation (O-BT) has been reported as the condition in which microorganisms are detected in blood or lymph nodes by a highly sensitive method. However, the clinical impact of preoperative O-BT on postoperative complication is unclear.

STUDY DESIGN

A prospective observational study with patients undergoing pancreatoduodenectomy for periampullary diseases was conducted. Blood samples were collected immediately after induction of anesthesia. The status of O-BT was investigated using bacterium-specific ribosomal RNA-targeted reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR). The impact of O-BT on surgical site infection (SSI) was analyzed.

RESULTS

A total of 155 patients were included. The positive rate in preoperative blood samples detected by RT-qPCR was significantly higher than that obtained by the culture method (32 of 155 vs 4 of 155, p < 0.001). Preoperative blood samples were contaminated with 1.0 to 19.2 bacterial cells/mL in positive patients, and 30 of the 41 detected microorganisms were obligate anaerobes. No differences in preoperative factors were observed between patients with positive and negative RT-qPCR results. The incidence of any SSI was significantly higher in patients with contaminated preoperative blood (≥1.2 bacterial cells/mL) than in other patients (14 of 27 vs 35 of 128, p = 0.013). Multivariable analysis indicated that contaminated preoperative blood was identified as one of the independent risk factors for SSI (odds ratio 2.71, 95% CI 1.04 to 7.24, p = 0.041).

CONCLUSIONS

O-BT, predominantly with obligate anaerobes, was commonly observed in preoperative blood samples. In addition to the previously known risk factors, O-BT may be one of the risk factors for SSI after pancreatoduodenectomy.

Peritoneal Lavage Tumor DNA as a Novel Biomarker for Predicting Peritoneal Recurrence in Pancreatic Ductal Adenocarcinoma

BACKGROUND

The clinical role of peritoneal lavage cytology (CY) in pancreatic ductal adenocarcinoma (PDAC) remains controversial, partly due to its low sensitivity. This study aimed to develop a new biomarker, defined as peritoneal lavage tumor DNA (ptDNA), using DNAs extracted from peritoneal lavage samples from patients with PDAC.

METHODS

Samples were collected intraoperatively from 89 PDAC patients who underwent pancreatectomy between 2012 and 2017. Droplet digital polymerase chain reaction (PCR) was used to measure ptDNA for detection of KRAS mutations. The ptDNA status and clinical characteristics were retrospectively evaluated.

RESULTS

Positive ptDNA was found in 41 patients, including all 9 patients positive for CY (CY+) and 32 patients negative for CY (CY-). The mutant allele frequency was significantly higher in the CY+ patients than in the CY- patients. The disease-free survival (DFS) and overall survival (OS) were significantly poorer in the high-ptDNA group than in the low-ptDNA group (median DFS, 11.0 vs. 18.8 months; p = 0.007; median OS, 28.7 vs not reached; p = 0.001). The survival curves of DFS and OS in the CY+ group were almost equal to those in the CY- and high-ptDNA group. In a multivariable analysis, ptDNA was an independent predictive factor for DFS (p = 0.025) and OS (p = 0.047). The estimated cumulative incidence of peritoneal recurrence was 45.5% in the high-ptDNA group. The ptDNA biomarker had a much higher sensitivity for peritoneal recurrence than CY, whereas CY had higher specificity.

CONCLUSIONS

As a promising biomarker, ptDNA may predict poor prognosis and peritoneal recurrence in PDAC, resolving the controversy surrounding CY.

Impact of Qualitative and Quantitative Biliary Contamination Status on the Incidence of Postoperative Infection Complications in Patients Undergoing Pancreatoduodenectomy

BACKGROUND

Bacterial contamination status may differ under different biliary drainage conditions. The purpose of this study was to determine the impact of qualitative and quantitative biliary bacterial contamination on the incidence of infection complications in patients undergoing pancreatoduodenectomy.

METHODS

Patients undergoing pancreatoduodenectomy for periampullary diseases with different biliary drainage conditions, such as external drainage (ED), internal drainage (ID), and no drainage (ND), were included. Bile was collected intraoperatively, and biliary contamination status was qualified and quantified using bacterium-specific ribosomal RNA-targeted reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The impact of biliary contamination status on infection complications was analyzed.

RESULTS

A total of 152 patients were included (38 with ED, 40 with ID, and 74 with ND). The positive rate of microorganisms in bile was higher in the ID group (98%) compared with the ED group (82%, p = 0.021) and the ND group (65%, p < 0.001). The number of microorganisms detected in bile samples was higher in the ID group compared with the ED group (median 489,788 vs. 5375 bacteria/mL of bile, p < 0.001). With multivariate analysis, soft pancreas, intraoperative bleeding (> 600 mL), and biliary contamination by Atopobium cluster were identified as independent risk factors for infection complications. Biliary contamination by Atopobium cluster was significantly higher in the ID group compared with the other groups.

CONCLUSIONS

Biliary bacterial contamination is more frequently induced by ID than either ED or ND. In addition to the previously known risk factors, biliary contamination with Atopobium cluster may be one of the risk factors of infection complications following pancreatoduodenectomy.

Exploration of Exosomal Micro RNA Biomarkers Related to Epithelial-to-Mesenchymal Transition in Pancreatic Cancer

BACKGROUND/AIM

Epithelial-to-mesenchymal transition (EMT) plays important roles in cancer progression. This study aimed to identify the exosomal miRNA (exo-miRNA) profiles related to the EMT status in pancreatic cancer (PC).

MATERIALS AND METHODS

Comprehensive exo-miRNA-expression profiles in the culture media of PC cell lines were analyzed through microarray technology. The identified miRNAs were analyzed to investigate their clinical implication using The Cancer Genome Atlas (TCGA) dataset and clinical samples.

RESULTS

We prioritized 291 exo-miRNAs differentially expressed between epithelial and mesenchymal cell types. Among them, survival analysis based on the TCGA dataset revealed that mir-196b and mir-204 significantly stratify the prognosis of PC cases. In addition, analysis of cell lines indicated miR-196b-3p as a mesenchymal marker and miR-204-3p as an epithelial marker. Finally, we demonstrated that miR-196b-3p and miR-204-3p in serum exosomes were differentially expressed among intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, and PC.

CONCLUSION

Serum exo-miRNA biomarkers potentially identify the pancreatic tumor status through less-invasive methods.

Detection of Circulating Tumor DNA in Patients with Pancreatic Cancer Using Digital Next-Generation Sequencing

Circulating tumor DNA (ctDNA) measurements can be used to estimate tumor burden, but avoiding false-positive results is challenging. Herein, digital next-generation sequencing (NGS) is evaluated as a ctDNA detection method. Plasma KRAS and GNAS hotspot mutation levels were measured in 140 subjects, including 67 with pancreatic ductal adenocarcinoma and 73 healthy and disease controls. To limit chemical modifications of DNA that yield false-positive mutation calls, plasma DNA was enzymatically pretreated, after which DNA was aliquoted for digital detection of mutations (up to 384 aliquots/sample) by PCR and NGS. A digital NGS score of two SDs above the mean in controls was considered positive. Thirty-seven percent of patients with pancreatic cancer, including 31% of patients with stages I/II disease, had positive KRAS codon 12 ctDNA scores; only one patient had a positive GNAS mutation score. Two disease control patients had positive ctDNA scores. Low-normal-range digital NGS scores at mutation hotspots were found at similar levels in healthy and disease controls, usually at sites of cytosine deamination, and were likely the result of chemical modification of plasma DNA and NGS error rather than true mutations. Digital NGS detects mutated ctDNA in patients with pancreatic cancer with similar yield to other methods. Detection of low-level, true-positive ctDNA is limited by frequent low-level detection of false-positive mutation calls in plasma DNA from controls.

Phase II study of chemoradiotherapy combined with gemcitabine plus nab-paclitaxel for unresectable locally advanced pancreatic ductal adenocarcinoma (NUPAT 05 Trial): study protocol for a single arm phase II study

The efficacy of nab-paclitaxel combined with gemcitabine (GnP) and of chemoradiotherapy (CRT) for unresectable locally advanced pancreatic ductal adenocarcinoma (UR-LA PDAC) is still unclear. We previously conducted a phase I study of CRT using GnP and determined the recommended dose and have now designed a phase II trial to evaluate the efficacy of CRT incorporating GnP for UR-LA PDAC. Eligibility criteria are chemotherapy-naïve patients with UR-LA PDAC as defined by the NCCN guidelines version 2. 2016. Study patients will receive 100 mg/m² nab-paclitaxel and 800 mg/m² gemcitabine on Days 1, 8, and 15 per 4-week cycle with concurrent radiation therapy (total dose of 50.4 Gy in 28 fractions of 1.8 Gy per day, 5 days per week). Treatment will be continued until disease progression or surgery, which is to be performed only for patients in whom the disease is well-controlled at 8 months from beginning the protocol treatment. Primary endpoint is 2-year overall survival rate and co-primary endpoint is resection rate. Secondary endpoints are overall survival, progression free survival, time to treatment failure, response rate, disease control rate, early tumor shrinkage, depth of response, reduction of SUV-max on PET–CT, serum tumor markers, relative dose intensity, safety, and Quality of life. This study will show the efficacy and safety of chemoradiotherapy combined with GnP.

Homeobox C10 Influences on the Malignant Phenotype of Gastric Cancer Cell Lines and its Elevated Expression Positively Correlates with Recurrence and Poor Survival

BACKGROUND

The detection of molecules and mechanisms affecting the malignant phenotype of gastric cancer cells may contribute to the identification of biomarkers for metastasis and recurrence, and such molecules may serve as targets of therapy. For this purpose, in this study transcriptome analysis was performed using surgically resected specimens from patients with gastric cancer with synchronous metastasis. We identified homeobox C10 (HOXC10) as the most highly expressed gene in gastric cancer tissues compared with the adjacent noncancerous gastric mucosa.

METHODS

Polymerase chain reaction (PCR) array analysis was performed to identify genes coordinately expressed with HOXC10. The effects of inhibiting HOXC10 on malignant phenotype was evaluated using HOXC10 knockout gastric cancer cell lines, and antibody array analysis was performed to assess the effect of HOXC10 knockout on intracellular signaling. We used a mouse subcutaneous xenograft model to evaluate the tumorigenicity. HOXC10 expression was determined in gastric cancer tissues acquired from 300 patients with gastric cancer.

RESULTS

PCR array analysis revealed that the levels of HOXC10 messenger RNA positively correlated with those of FGFBP1 and SOX10. The phosphorylation of ERK1/2 was decreased in HOXC10 knockout cells. HOXC10 knockout significantly suppressed proliferation by increasing apoptosis and reducing the migration and invasiveness of gastric cancer cells. Mouse xenograft models revealed that the tumorigenicity of HOXC10 knockout cells was attenuated compared with the parental cells. The relatively high expression levels of HOXC10 in gastric cancer tissues were significantly associated with hepatic and peritoneal recurrence, as well as worse prognosis.

CONCLUSIONS

Our results indicated that HOXC10 enhances the malignant phenotype of gastric cancer cells. The expression levels of HOXC10 may therefore serve as a prognostic biomarker and the products of HOXC10 may provide targets of therapy.

Increased Expression of DNAJC12 is Associated with Aggressive Phenotype of Gastric Cancer

BACKGROUND

Identification of gastric cancer-related molecules is necessary to elucidate the pathological mechanisms of this heterogeneous disease. The purpose of this study was to identify novel genes associated with aggressive phenotypes of gastric cancer.

METHODS

Global expression profiling was conducted using tissues from four patients with metastatic gastric cancer to identify genes overexpressed in gastric cancer. Fifteen gastric cell lines and 262 pairs of surgically resected gastric tissues were subjected to mRNA expression analysis. The contribution of the candidate gene on gastric cancer cell proliferation, invasion, adhesion, and migration were evaluated using small interfering RNA.

RESULTS

DnaJ heat shock protein family (Hsp40) member C12 (DNAJC12) was identified as a candidate gene by transcriptome analysis. In clinical samples, DNAJC12 mRNA levels were higher in gastric cancer tissues compared with normal adjacent tissues. Patients with high DNAJC12 expression showed significantly shorter overall survival in our cohort and in the extra-validation cohort analyzed by a published microarray dataset. High DNAJC12 expression in gastric cancer tissues was significantly associated with lymphatic involvement, infiltrative growth type, lymph node metastasis, and advanced stage and was identified as an independent prognostic factor for overall survival in multivariable analysis. Increased expression of DNAJC12 was found in 12 of 14 examined gastric cancer cell lines. Knockdown of DNAJC12 expression significantly decreased the proliferation and invasion abilities of gastric cancer cells.

CONCLUSIONS

Our findings support DNAJC12 as a candidate gene associated with aggressive phenotypes of gastric cancer.

Perioperative and prognostic implication of albumin-bilirubin-TNM score in Child-Pugh class A hepatocellular carcinoma

BACKGROUND AND AIM

A reliable classification for predicting postoperative prognosis and perioperative risk of hepatocellular carcinoma (HCC) patients is required to make a precise decision for HCC treatment. In the present study, we assessed the perioperative and prognostic importance of indocyanine green (ICG) testing, tumor-node-metastasis (TNM) stage, albumin-bilirubin (ALBI) grade, and ALBI-TNM (ALBI-T) score using consecutive resected HCC cases.

METHODS

Between 1998 and 2011, 273 consecutive patients who underwent primary and curative hepatectomy for HCC were identified. Among these 273 cases, 235 Child-Pugh class A patients were enrolled in the present study.

RESULTS

Correlation analysis showed that the value of linear predictor for ALBI grade was significantly correlated with ICG 15-minute retention rates (r = 0.51, P < 0.0001). Survival analysis for both recurrence-free survival (RFS) and overall survival (OS) showed there were significant differences between the two groups stratified by stage or ALBI-T score (stage, RFS: P = 0.01, OS: P = 0.003; ALBI-T, RFS: P < 0.0001, OS: P < 0.0001). In addition, Cox proportional hazard model identified ALBI-T score was a significant predictor for both RFS and OS (RFS, P = 0.001; OS, P = 0.004). Furthermore, ALBI-T score could predict perioperative risk in hepatectomy such as longer operation time and excessive intraoperative blood loss.

CONCLUSIONS

This study showed a robust association of ALBI-T score with postoperative HCC patient survival and perioperative risk in hepatectomy. ALBI-T score can be used as a simple and powerful tool for assessing HCC patients with further study.

Copine 5 expression predicts prognosis following curative resection of esophageal squamous cell carcinoma

Patients with esophageal squamous cell carcinoma (ESCC) have a poor prognosis. Identification of biomarkers to accurately predict the risk of recurrence and survival following curative esophageal resection is required to improve patient outcomes. The copine 5 (CPNE5) gene encodes a calcium‑dependent lipid‑binding intracellular protein. Copine proteins interact with diverse target proteins that are components of pathways that aberrantly regulate the phenotypes of malignant cells. However, limited information is available on the role of CPNE5 in cancer. The present study investigated whether CPNE5 may serve as a predictive marker of the prognosis of patients with ESCC following curative resection. CPNE5 mRNA expression levels and the methylation status of the CPNE5 promotor region were measured in 11 ESCC cell lines. CPNE5 mRNA expression levels in 106 pairs of surgically resected specimens were measured, and their associations with clinicopathological characteristics were analyzed. The CPNE5 mRNA expression levels in 9 ESCC cell lines were decreased compared with those of the non-tumorigenic esophageal mucosa cell line Het‑1A. Bisulfite sequencing detected the methylation of the CPNE5 promotor region in all cell lines tested, including Het‑1A. Furthermore, analysis of tissues revealed that CPNE5 mRNA expression was significantly lower in ESCC cells compared with cognate non-cancerous adjacent mucosal cells. Kaplan‑Meier analysis revealed that patients with low CPNE5 expression experienced significantly shorter overall survival. Multivariable analysis identified low CPNE5 expression to be an independent prognostic factor of OS. Analysis of recurrence patterns revealed that significantly more patients with local recurrence expressed lower levels of CPNE5 mRNA. These findings indicated that CPNE5 expression in ESCC tissues may serve as an informative biomarker for predicting ESCC recurrence, particularly in patients with local recurrence, and may help to ensure that patients receive optimal treatment and follow‑up.

Expression of sushi domain containing two reflects the malignant potential of gastric cancer

Hepatic recurrence of gastric cancer (GC) is uncontrollable. Discovery of causative oncogenes and the development of sensitive biomarkers to predict hepatic recurrence are required to improve patients’ outcomes. In this study, recurrence pattern‐specific transcriptome analysis of 57 749 genes was conducted to identify mRNAs specifically associated with hepatic metastasis of patients with stage III GC who underwent curative resection. GC cell lines were subjected to mRNA expression analysis, PCR array analysis, and siRNA‐mediated knockdown. The expression levels of primary cancer tissues from 154 patients with resectable GC were determined and correlated with clinicopathological variables. Among 21 genes significantly overexpressed specifically in patients with hepatic recurrence, Sushi domain containing 2 (SUSD2) was selected as a promising target. PCR array analysis revealed that SUSD2 mRNA levels positively correlated with those of FZD7, CDH2, TGFB1, SPARC, ITGA5, and ZEB1. Functional analysis revealed that knockdown of SUSD2 significantly reduced the proliferation, migration, and invasiveness GC cell lines. Patients with high SUSD2 expression were more likely to experience shorter disease‐free and overall survival. Analysis of the relation between disease recurrence pattern and SUSD2 levels revealed that significantly more patients with hepatic metastases expressed higher levels of SUSD2 mRNA. The cumulative incidence of hepatic recurrence was greater in patients with high SUSD2 expression. In conclusion, SUSD2 likely contributes to the malignant potential of GC and may serve as a novel biomarker that predicts hepatic recurrence after curative resection.

Impact of the Controlling Nutritional Status Score on the Prognosis After Curative Resection of Pancreatic Ductal Adenocarcinoma

OBJECTIVES

The controlling nutritional status (CONUT) score is a useful tool to evaluate immune-nutritional status. This study aimed to investigate the impact of the CONUT score on short- and long-term outcomes after curative resection of pancreatic ductal adenocarcinoma (PDAC).

METHODS

Consecutive 344 PDAC patients receiving pancreatectomy without neoadjuvant therapy were examined retrospectively. After the best predictive value of the CONUT score for survival was identified, association between the CONUT score and long-term outcomes was evaluated using log-rank tests and a Cox regression model. Then correlations between the CONUT score and postoperative complications were analyzed.

RESULTS

The optimal cutoff value of the CONUT score was 4. The high CONUT score group showed significantly lower overall survival than the low CONUT score group (P = 0.002). In contrast, no significant difference in recurrence-free survival was found (P = 0.43). A multivariate analysis demonstrated that high CONUT score had an independent association with overall survival (hazard ratio, 1.64; P = 0.003). The CONUT score showed no association with postoperative pancreatic fistula, Clavien-Dindo grade, or postoperative hospital stay.

CONCLUSION

The CONUT score had an independent association with survival in patients with PDAC after pancreatectomy and was not associated with recurrence or postoperative complications.

Validation Strategy for Ultrasensitive Mutation Detection

BACKGROUND

Ultrasensitive detection of low-abundance DNA point mutations is a challenging molecular biology problem, because nearly identical mutant and wild-type molecules exhibit crosstalk. Reliable ultrasensitive point mutation detection will facilitate early detection of cancer and therapeutic monitoring of cancer patients.

OBJECTIVE

The objective of this study was to develop a method to correct errors in low-level cell line mixes.

MATERIALS AND METHODS

We tested sample mixes with digital-droplet PCR (ddPCR) and next-generation sequencing.

RESULTS

We introduced two corrections: baseline variant allele frequency (VAF) in the parental cell line was used to correct for copy number variation; and haplotype counting was used to correct errors in cell counting and pipetting. We found ddPCR to have better correlation for detecting low-level mutations without applying any correction (R² = 0.80) and be more linear after introducing both corrections (R² = 0.99).

CONCLUSIONS

The VAF correction was found to be more significant than haplotype correction. It is imperative that various technologies be evaluated against each other and laboratories be provided with defined quality control samples for proficiency testing.

Abstract 3330: Molecular surgical margin analysis of pancreatic cancers

Background: Pancreatic cancer is one of the incurable cancers among solid malignancies. Basically, R0 tumor resection could be one of the critical factors for their prognosis. However, pathological diagnosis of surgical margins is sometimes unreliable due to tissue shrinkage and skipped lesion like tumor budding. We applied our ‘molecular surgical margin analysis' using tissue imprinting procedure to evaluate the precise surgical margin status of the surgical specimens after pancreatoduodenectomy.

Methods: Quantitative methylation specific PCR (QMSP) assay for 3 representative tumor-specific methylation markers (CD1D, KCNK12, PAX5) were established and validated by paired normal and tumor tissues from pancreatic ductal carcinoma cases (n=48). Then, these markers were applied to prospectively collected peritoneal lavage samples (n=16), drainage fluid samples (n=18) and surgical margin imprinting samples (n=11).

Results: QMSP values of tumor tissues were significantly higher than adjacent normal tissues and relatively high specificity to cancer cells in all three markers with optimal cut-off values (CD1D: P&lt;0.001, 94%, KCNK12: P=0.001, 75%, PAX5: P&lt;0.001, 87%). These marker positive cases also showed marginally or significantly poor overall survival in univariate analysis (CD1D: HR=1.78, P=0.083, KCNK12: HR=2.57, P=0.005, PAX5: HR=2.64, P=0.003). Since these markers were revealed to be very cancer-specific, we tried to use them as cancer detection markers in clinical samples. 1) CD1D methylation was positive in 6 cases among 16 cases. Although 4 cases showed histopathologically positive, 2 cases were negative. These cases might have subclinically positive cancer cells in the fluid. Actually, one of them relapsed 5 months after the surgery. 2) CD1D methylation was positive in 4 cases among 18 postoperative cases. These cases were all treated with surgery first, while neoadjuvant cases showed no methylation in postoperative drainage fluid. 3) Molecular surgical margin analysis revealed 4 positive cases and 7 negative cases. To find the meaning of molecular margin positive, we still following-up these cases.

Conclusion: Very cancer-specific methylation detection assay was established. Although we still need to follow-up the cases for a year or more, invisible cancer cells in the fluid or on the surgical margin might have an association with tumor recurrence after the surgery.

Citation Format: Masamichi Hayashi, Suguru Yamada, Hiroshi Tanabe, Yoshiyasu Kato, Katsuhito Tanaka, MItsuru Tashiro, Haruyoshi Tanaka, Tomonari Asano, Hideki Takami, Masaya Suenaga, Yukiko Niwa, Yasuhiro Kodera. Molecular surgical margin analysis of pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3330.

Genome-Wide Somatic Copy Number Alterations and Mutations in High-Grade Pancreatic Intraepithelial Neoplasia

To obtain a better understanding of the genetic alterations of high-grade pancreatic intraepithelial neoplasia (HG-PanIN), we performed whole-genome copy number analysis by using single nucleotide polymorphism microarrays and targeted next-generation sequencing of 11 microdissected HG-PanIN and two low-grade PanIN lesions associated with HG-PanIN. HG-PanIN mutation profiles were compared with those of their associated invasive pancreatic ductal adenocarcinoma. All PanIN lesions harbored somatic KRAS mutations. The most common copy number losses in the HG-PanIN were at the CDKN2A (9p21), TP53 (17p13), and SMAD4 (18q21) loci. Chromosomal losses in HG-PanIN were also found at 6p25-p24, 6q11-q27, 12q24, and 17q23-q24. Biallelic inactivation of CDKN2A and TP53 was detected in five of eight and in three of eight evaluable PanIN lesions, respectively. None of the HG-PanIN lesions had SMAD4 mutations or homozygous deletion. Copy number gains were noted at the MYC (8q24) and CCNE1 (19q12) loci and at 1q25-q31. Four HG-PanINs and one low-grade PanIN harbored chromothripsis-like regions. Five of seven pancreatic ductal adenocarcinomas evaluated had additional mutations that were not found in their associated HG-PanIN. HG-PanIN harbors widespread copy number alterations and commonly shows evidence of biallelic inactivation of CDKN2A and TP53 but not SMAD4. Chromothripsis events contribute to the copy number alterations of HG-PanIN.

A novel dual-marker expression panel for easy and accurate risk stratification of patients with gastric cancer

Development of specific biomarkers is necessary for individualized management of patients with gastric cancer. The aim of this study was to design a simple expression panel comprising novel molecular markers for precise risk stratification. Patients (n = 200) who underwent gastrectomy for gastric cancer were randomly assigned into learning and validation sets. Tissue mRNA expression levels of 15 candidate molecular markers were determined using quantitative PCR analysis. A dual‐marker expression panel was created according to concordance index (C‐index) values of overall survival for all 105 combinations of two markers in the learning set. The reproducibility and clinical significance of the dual‐marker expression panel were evaluated in the validation set. The patient characteristics of the learning and validation sets were well balanced. The C‐index values of combinations were significantly higher compared with those of single markers. The panel with the highest C‐index (0.718) of the learning set comprised SYT8 and MAGED2, which clearly stratified patients into low‐, intermediate‐, and high‐risk groups. The reproducibility of the panel was demonstrated in the validation set. High expression scores were significantly associated with larger tumor size, vascular invasion, lymph node metastasis, peritoneal metastasis, and advanced disease. The dual‐marker expression panel provides a simple tool that clearly stratifies patients with gastric cancer into low‐, intermediate‐, and high risk after gastrectomy.

Troponin I2 as a Specific Biomarker for Prediction of Peritoneal Metastasis in Gastric Cancer

BACKGROUND

Although peritoneal metastasis is a serious concern in patients with gastric cancer, no acceptable and specific biomarker is available. We aimed to identify a candidate biomarker to predict peritoneal metastasis of gastric cancer.

METHODS

Metastatic pathway-specific transcriptome analysis was conducted by comparison of patient groups with no recurrence and with peritoneal, hepatic, and nodal recurrence. Fifteen cell lines and 262 pairs of surgically resected gastric tissues were subjected to messenger RNA (mRNA) expression analysis. Polymerase chain reaction array analysis was performed to explore coordinately expressed cancer-related genes. To evaluate the in situ protein localization and expression patterns, immunohistochemical staining was performed.

RESULTS

From transcriptome data, troponin I2 (TNNI2) was identified as a candidate molecule specifically overexpressed in gastric cancer prone to peritoneal metastasis. TNNI2 mRNA was expressed at differential levels, independent of differentiated phenotype of cell lines. Epithelial to mesenchymal transition-related genes, tumor inhibitor of metalloproteinase 1 (TIMP1), and vacuolar protein sorting 13 homolog A (VPS13A) were expressed with TNNI2 at correlation coefficient > 0.7. The optimal cutoff of TNNI2 expression was determined as 0.00017. High TNNI2 expression was significantly and specifically associated with peritoneal metastasis and served as an independent risk marker for peritoneal recurrence after curative gastrectomy. Prevalence of peritoneal recurrence increased in parallel with staining intensity of TNNI2.

CONCLUSIONS

TNNI2 expression in gastric tissues may serve as a specific biomarker for prediction of peritoneal metastasis of gastric cancer and contribute to improvement of patient management.

Significance of Lysyl oxidase‑like 2 gene expression on the epithelial‑mesenchymal status of hepatocellular carcinoma

In the present study, we investigated the role of lysyl oxidase‑like 2 (LOXL2), the correlation between LOXL2 and epithelial to mesenchymal transition (EMT) and the effects of using β‑aminopropionitrile (BAPN) to inhibit LOXL2 with the aim of reducing tumor progression in hepatocellular carcinoma (HCC). The expression level of LOXL2 was evaluated in HCC and adjacent non‑cancerous tissues using quantitative reverse transcription polymerase chain reaction and clinicopathological analyses. The effects of BAPN on cell proliferation, migration and invasion were investigated in vitro. Additionally, LOXL2 expression was assessed in the culture supernatants of HCC cell lines. Our results revealed that LOXL2 expression was higher in HCC cell lines and tissues. There was a significant correlation between EMT status and LOXL2 levels (P=0.004). BAPN reduced migration and invasion in HCC cells. HCC patients with high levels of LOXL2 expression had relatively shorter disease‑free survival (P=0.009) and overall survival (P=0.035). The expression level of LOXL2 was similar between cell supernatants and HCC cell lines. A multivariate analysis demonstrated that portal vein invasion (P=0.015), venous invasion (P=0.026), serum AFP (α‑fetoprotein) levels (P=0.019) and LOXL2 expression (P=0.009) were independent prognostic factors. Our results indicated that a higher level of LOXL2 may contribute to tumor progression, indicating that LOXL2 has clinical value as a therapeutic target in HCC.

Genetic variants of DNA repair-related genes predict efficacy of TAS-102 in patients with refractory metastatic colorectal cancer

Background

Tri-phosphorylated trifluridine (FTD) incorporation into DNA is TAS-102's main anti-tumor action. We tested whether genetic polymorphisms in homologous recombination (HR) and cell cycle checkpoint pathway for DNA repair is associated with outcomes in refractory metastatic colorectal cancer (mCRC) patients treated with TAS-102.

Patients and methods

We analyzed genomic DNA extracted from 233 samples of three cohorts: an evaluation cohort of 52 patients receiving TAS-102, a validation cohort of 129 patients receiving TAS-102 and a control cohort of 52 patients receiving regorafenib. Single nucleotide polymorphisms of genes involved in HR (ATM, BRCA1, BRCA2, XRCC3, FANCD2, H2AX, RAD51) and cell cycle checkpoint (ATR, CHEK1, CHEK2, CDKN1A, TP53, CHE1, PIN1, PCNA) were analyzed by PCR-based direct sequencing.

Results

In univariate analysis for the evaluation cohort, patients with any G allele in ATM rs609429 had longer overall survival (OS) than those with the C/C variant (8.7 vs. 4.4 months, HR 0.37, 95% CI: 0.14-0.99, P = 0.022). Patients carrying any A allele in XRCC3 rs861539 had significantly longer progression-free survival (PFS) (3.8 vs. 2.3 months, HR 0.44, 95% CI: 0.21-0.92, P = 0.024) and OS (15.6 vs. 6.3 months, HR 0.25, 95% CI: 0.08-0.79, P = 0.012) than those with the G/G variant. In multivariable analysis, ATM rs609429 remained significant for OS (P = 0.020). In the validation cohort, patients having ATM rs609429 with any G allele showed longer OS and PFS; the G/A variant in XRCC3 rs861539 showed longer OS, though without statistical significance.

Conclusion

Genetic variants in the HR pathway may predict clinical outcome in mCRC patients receiving TAS-102.

Evaluation of tuberculosis contact investigations in Japan

SETTING

Although monitoring and evaluation using standardised indicators is an important aspect of tuberculosis (TB) contact investigation, no attempts have been made to systematically evaluate contact investigations in Japan.

OBJECTIVE

To evaluate TB contact investigations conducted in public health centres (PHCs) by estimating the scores of selected indicators.

DESIGN

A cross-sectional study was conducted in 2012 to estimate six selected indicator scores for contact tracing, contact evaluation and contact treatment at 11 PHCs using the TB registry and relevant contact investigation records of all forms of newly notified active TB cases. Indicator scores were compared across PHCs using median and interquartile range (IQR).

RESULTS

A total of 2527 contacts of 313 index TB cases were identified; of these, 1874 were evaluated using the tuberculin skin test (TST) or interferon-gamma release assays (IGRAs). Of 187 contacts who were TST/IGRA-positive, 15 were diagnosed with active TB. Consistently higher medians and lower IQRs were obtained for indicators of contact tracing and contact evaluation than those of contact treatment.

CONCLUSION

Our study is the first to evaluate the performance of TB contact investigations in Japan using standardised indicators; the study indicated performance gaps, especially in the treatment for latent tuberculous infection among contacts.

Phase I study of chemoradiotherapy using gemcitabine plus nab-paclitaxel for unresectable locally advanced pancreatic cancer

523

Background: Gemcitabine plus nab-paclitaxel (GnP) treatment is recommended for metastatic pancreatic adenocarcinoma (PDAC), and has been widely spread in our clinics. However, the usefulness for the patients with locally advanced PDAC is still controversial. We designed the phase I study to assess the toxicity and decide the recommended dose based on dose-limiting toxicity (DLT) of concurrent chemoradiotherapy using GnP for unresectable locally advanced (UR-LA) PDAC. Methods: UR-LA PDAC patients were enrolled in this clinical trial. The patients received the GnP on days 1, 8 and 15 every 28 days, and the cycles were repeated until PD. The patients were scheduled to receive gemcitabine (mg/m2) and nab-paclitaxel (mg/m2) at 5 dose levels: 400/75 (level 0), 600/75 (level 1), 600/100 (level 2), 800/100 (level 3) and 800/125 (level 4). Radiation therapy was delivered as a total dose of 50.4 Gy in 28 fractions, 1.8Gy per day. DLT was defined as grade 4 leucopenia or neutropenia ≥ 3 days, grade 3 neutropenia with fever ≥ 38℃, grade 3 or 4 thrombopenia, grade 3 non-hematological toxicity and > 14 days delay of treatment. Response and disease control rate, safety, adverse events, PFS and OS were evaluated. Results: Twelve patients were enrolled in this study. Treatment was well tolerated, and every 12 patients completed radiotherapy of 50.4 Gy. Our recommended dose was level 3, gemcitabine 800 mg/m2 and nab-paclitaxel 100 mg/m2. One patient experienced the DLT. The response rate was 41.7% and disease control rate was 75% (PR: 5, SD: 4, PD: 3). Median OS was 9.0 months. Among 12 patients, 6 (50%) patients underwent conversion surgery, and the pathological CR was observed in 2 patients. Conclusions: The concurrent chemoradiotherapy using GnP for UR-LA PDAC can be delivered safely and the high rate of conversion surgery was observed in our clinical trial. Based on this results, we will proceed the phase-II study. Clinical trial information: UMIN000020475.

Clinical implication of nutrition for neoadjuvant therapy and impact of nutritional support in pancreatic cancer

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Background: Several studies have shown that nutritional support is important to reduce chemotherapy-related toxicities and improve tolerance to chemotherapy, but little is known about the nutritional influence of neoadjuvant therapy (NAT) for pancreatic cancer. The aim of this study was to assess the influence of NAT on nutritional status and the effectiveness of postoperative nutritional support in patients with NAT for pancreatic cancer. Methods: Between 2010 and 2017, 169 consecutive patients who underwent pancreatoduodenectomy of pancreatic cancer were enrolled, and divided into the neoadjuvant group (NAG, n = 70) and the control group (CG, n = 99). We assessed the change of nutritional index (body weight, albumin and rapid turnover proteins; retinol binding protein, prealbumin and transferrin), inflammatory index, and inflammation-based prognostic scores during NAT. Perioperative change of rapid turnover proteins at the point of pre-operation, postoperative day (POD) 5, POD12 and POD21, and perioperative and oncological outcomes between NAG and CG were evaluated. Finally, we divided NAG into nutrition group (n = 27) who received postoperative enteral immunonutrition from POD 1 to POD 21 and without nutrition group (n = 41), and compared perioperative change of rapid turnover proteins between two groups. Results: After NAT, the retinol binding protein, prealbumin, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio and prognostic nutrition index significantly got worse in NAG (P < 0.05). The recovery of rapid turnover proteins after POD5 was significantly worse in NAG compared to CG (P < 0.05). There was no significant difference in the incidence of postoperative complications and time to adjuvant therapy between two groups. The recovery of retinol binding protein and prealbumin after POD12 was significantly better in nutrition group compared to without nutrition group (P < 0.05). Conclusions: NAT for pancreatic cancer could decrease nutritional status and its postoperative recovery. Postoperative enteral nutrition could be effective in patients with NAT for pancreatic cancer. Based on these results, we plan to perform the nutritional support at earlier stage of therapy.

Pancreatic Juice Mutation Concentrations Can Help Predict the Grade of Dysplasia in Patients Undergoing Pancreatic Surveillance

Purpose: The measurement of mutations in pancreatic juice samples collected from the duodenum during endoscopic ultrasound (EUS) may improve the diagnostic evaluation of patients undergoing pancreatic surveillance. Our aim was to evaluate the accuracy of using pancreatic juice mutation concentrations to predict the presence and histologic grade of neoplasia in the pancreas.Experimental Design: Digital next-generation sequencing (NGS) of pancreatic juice DNA using a targeted 12-gene panel was performed on 67 patients undergoing pancreatic evaluation during EUS, including patients with pancreatic ductal adenocarcinoma, patients who subsequently underwent pancreatic resection for precursor lesions, patients undergoing surveillance for their familial/inherited susceptibility to pancreatic cancer, and normal pancreas disease controls.Results: Patients with pancreatic cancer or high-grade dysplasia as their highest grade lesion had significantly higher pancreatic juice mutation concentrations than all other subjects (mean/SD digital NGS score; 46.6 ± 69.7 vs. 6.2 ± 11.6, P = 0.02). Pancreatic juice mutation concentrations distinguished patients with pancreatic cancer or high-grade dysplasia in their resection specimen from all other subjects with 72.2% sensitivity and 89.4% specificity [area under the curve (AUC) = 0.872]. Mutant TP53/SMAD4 concentrations could distinguish patients with pancreatic cancer or high-grade dysplasia in their resection specimen from all other subjects with 61.1% sensitivity and 95.7% specificity (AUC = 0.819). Among 31 high-risk individuals under surveillance, 2 of the 3 individuals with most abnormal pancreatic juice mutation profiles also had the most abnormalities on pancreatic imaging.Conclusions: Pancreatic juice mutation analysis using digital NGS has potential diagnostic utility in the evaluation of patients undergoing pancreatic surveillance. Clin Cancer Res; 24(12); 2963-74. ©2018 AACRSee related commentary by Lipner and Yeh, p. 2713.

Using an endoscopic distal cap to collect pancreatic fluid from the ampulla (with video)

BACKGROUND AND AIMS

Duodenal collections of pancreatic fluid can be used as a source of mutations and other markers of pancreatic ductal neoplasia, but admixing pancreatic juice with duodenal contents lowers the concentrations of mutations. Collecting pancreatic fluid directly from the ampulla could yield a purer sample of pancreatic fluid.

METHODS

We used an endoscopic distal cap attachment to "cap" the ampulla and collect secretin-stimulated pancreatic fluid samples for 5 minutes from 81 patients undergoing pancreatic evaluation as part of the Cancer of the Pancreas Screening studies. We compared mutation concentrations (K-ras and GNAS) measured by droplet-digital PCR (ddPCR) in "cap-collected juice" samples to those found in juice samples obtained from 77 patients collected by aspiration from the duodenal lumen without capping the ampulla.

RESULTS

Among all subjects, mutation concentrations were higher in pancreatic juice samples collected using the endoscopic cap method (median, .028%; IQR, 0-.077) compared with the noncap-collected (median, .019%; IQR, 0-.044; P = .055). Among pancreatic juice samples with detectable mutations, mutation concentrations were higher in the cap-collected juice samples than in those collected without the cap (.055%; IQR, .026-.092 vs .032%; IQR, .020-.066; P = .031).

CONCLUSIONS

Collecting pancreatic juice directly from the ampulla using an endoscopic distal cap yields higher concentrations of pancreatic fluid mutations.

Impact of genetic variations in the MAPK signaling pathway on outcome in metastatic colorectal cancer patients treated with first-line FOLFIRI and bevacizumab: data from FIRE-3 and TRIBE trials

BACKGROUND

The MAPK-interacting kinase 1 (MKNK1) is localized downstream of the RAS/RAF/ERK and the MAP3K1/MKK/p38 signaling pathway. Through phosphorylation MKNK1 regulates the function of eukaryotic translation initiation factor 4E, a key player in translational control, whose expression is often upregulated in metastatic colorectal cancer patients (mCRC). Preclinical data suggest that MKNK1 increases angiogenesis by upregulating angiogenic factors. We therefore hypothesize that variations in the MKNK1 gene predict outcome in mCRC patients treated with first-line FOLFIRI and bevacizumab (bev).

PATIENTS AND METHODS

A total of 567 patients with KRAS wild-type mCRC in the randomized phase III FIRE-3 and TRIBE trials treated with first-line FOLFIRI/bev (discovery and validation cohorts) or FOLFIRI and cetuximab (cet) (control cohort) were included in this study. Five single-nucleotide polymorphisms in the MAPK signaling pathway were analyzed.

RESULTS

AA genotype carriers of the MKNK1 rs8602 single-nucleotide polymorphism treated with FOLFIRI/bev in the discovery cohort (FIRE-3) had a shorter progression-free survival (PFS) than those harboring any C (7.9 versus 10.3 months, Hazard ratio (HR) 1.73, P = 0.038). This association could be confirmed in the validation cohort (TRIBE) in multivariable analysis (PFS 9.0 versus 11.0 months, HR 3.04, P = 0.029). Furthermore, AA carriers in the validation cohort had a decreased overall response rate (25% versus 66%, P = 0.049). Conversely, AA genotype carriers in the control group receiving FOLFIRI/cet did not show a shorter PFS. By combining both FOLFIRI/bev cohorts the worse outcome among AA carriers became more significant (PFS 9.0 versus 10.5 months) in univariable (HR 1.74, P = 0.015) and multivariable analysis (HR 1.76, P = 0.022). Accordingly, AA carriers did also exhibit an inferior overall response rate compared with those harboring any C (36% versus 65%, P = 0.005).

CONCLUSION

MKNK1 polymorphism rs8602 might serve as a predictive marker in KRAS wild-type mCRC patients treated with FOLFIRI/bev in the first-line setting. Additionally, MKNK1 might be a promising target for drug development.

Digital next-generation sequencing identifies low-abundance mutations in pancreatic juice samples collected from the duodenum of patients with pancreatic cancer and intraductal papillary mucinous neoplasms

OBJECTIVE

Secretin-stimulated pancreatic juice contains DNA shed from cells lining the pancreatic ducts. Genetic analysis of this fluid may form a test to detect pancreatic ductal neoplasia.

DESIGN

We employed digital next-generation sequencing ('digital NGS') to detect low-abundance mutations in secretin-stimulated juice samples collected from the duodenum of subjects enrolled in Cancer of the Pancreas Screening studies at Johns Hopkins Hospital. For each juice sample, digital NGS necessitated 96 NGS reactions sequencing nine genes. The study population included 115 subjects (53 discovery, 62 validation) (1) with pancreatic ductal adenocarcinoma (PDAC), (2) intraductal papillary mucinous neoplasm (IPMN), (3) controls with non-suspicious pancreata.

RESULTS

Cases with PDAC and IPMN were more likely to have mutant DNA detected in pancreatic juice than controls (both p<0.0001); mutant DNA concentrations were higher in patients with PDAC than IPMN (p=0.003) or controls (p<0.001). TP53 and/or SMAD4 mutations were commonly detected in juice samples from patients with PDAC and were not detected in controls (p<0.0001); mutant TP53/SMAD4 concentrations could distinguish PDAC from IPMN cases with 32.4% sensitivity, 100% specificity (area under the curve, AUC 0.73, p=0.0002) and controls (AUC 0.82, p<0.0001). Two of four patients who developed pancreatic cancer despite close surveillance had SMAD4/TP53 mutations from their cancer detected in juice samples collected over 1 year prior to their pancreatic cancer diagnosis when no suspicious pancreatic lesions were detected by imaging.

CONCLUSIONS

The detection in pancreatic juice of mutations important for the progression of low-grade dysplasia to high-grade dysplasia and invasive pancreatic cancer may improve the management of patients undergoing pancreatic screening and surveillance.

Deleterious Germline Mutations in Patients With Apparently Sporadic Pancreatic Adenocarcinoma

Purpose Deleterious germline mutations contribute to pancreatic cancer susceptibility and are well documented in families in which multiple members have had pancreatic cancer. Methods To define the prevalence of these germline mutations in patients with apparently sporadic pancreatic cancer, we sequenced 32 genes, including known pancreatic cancer susceptibility genes, in DNA prepared from normal tissue obtained from 854 patients with pancreatic ductal adenocarcinoma, 288 patients with other pancreatic and periampullary neoplasms, and 51 patients with non-neoplastic diseases who underwent pancreatic resection at Johns Hopkins Hospital between 2000 and 2015. Results Thirty-three (3.9%; 95% CI, 3.0% to 5.8%) of 854 patients with pancreatic cancer had a deleterious germline mutation, 31 (3.5%) of which affected known familial pancreatic cancer susceptibility genes: BRCA2 (12 patients), ATM (10 patients), BRCA1 (3 patients), PALB2 (2 patients), MLH1 (2 patients), CDKN2A (1 patient), and TP53 (1 patient). Patients with these germline mutations were younger than those without (mean ± SD, 60.8 ± 10.6 v 65.1 ± 10.5 years; P = .03). Deleterious germline mutations were also found in BUB1B (1) and BUB3 (1). Only three of these 33 patients had reported a family history of pancreatic cancer, and most did not have a cancer family history to suggest an inherited cancer syndrome. Five (1.7%) of 288 patients with other periampullary neoplasms also had a deleterious germline mutation. Conclusion Germline mutations in pancreatic cancer susceptibility genes are commonly identified in patients with pancreatic cancer without a significant family history of cancer. These deleterious pancreatic cancer susceptibility gene mutations, some of which are therapeutically targetable, will be missed if current family history guidelines are the main criteria used to determine the appropriateness of gene testing.

Genetic analyses of isolated high-grade pancreatic intraepithelial neoplasia (HG-PanIN) reveal paucity of alterations in TP53 and SMAD4

High-grade pancreatic intraepithelial neoplasia (HG-PanIN) is the major precursor of pancreatic ductal adenocarcinoma (PDAC) and is an ideal target for early detection. To characterize pure HG-PanIN, we analysed 23 isolated HG-PanIN lesions occurring in the absence of PDAC. Whole-exome sequencing of five of these HG-PanIN lesions revealed a median of 33 somatic mutations per lesion, with a total of 318 mutated genes. Targeted next-generation sequencing of 17 HG-PanIN lesions identified KRAS mutations in 94% of the lesions. CDKN2A alterations occurred in six HG-PanIN lesions, and RNF43 alterations in five. Mutations in TP53, GNAS, ARID1A, PIK3CA, and TGFBR2 were limited to one or two HG-PanINs. No non-synonymous mutations in SMAD4 were detected. Immunohistochemistry for p53 and SMAD4 proteins in 18 HG-PanINs confirmed the paucity of alterations in these genes, with aberrant p53 labelling noted only in three lesions, two of which were found to be wild type in sequencing analyses. Sixteen adjacent LG-PanIN lesions from ten patients were also sequenced using targeted sequencing. LG-PanIN harboured KRAS mutations in 94% of the lesions; mutations in CDKN2A, TP53, and SMAD4 were not identified. These results suggest that inactivation of TP53 and SMAD4 are late genetic alterations, predominantly occurring in invasive PDAC. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Lack of association between the pancreatitis risk allele CEL-HYB and pancreatic cancer

CEL-HYB is a hybrid allele that arose from a crossover between the 3’ end of the Carboxyl ester lipase (CEL) gene and the nearby CEL pseudogene (CELP) and was recently identified as a risk factor for chronic pancreatitis. Since chronic pancreatitis is a risk factor for the development of pancreatic cancer, we compared the prevalence of the CEL-HYB allele in patients with pancreatic ductal adenocarcinoma to spousal controls and disease controls. The CEL-HYB allele was detected using Sanger and next generation sequencing. There was no significant difference in the prevalence of the CEL-HYB allele between cases with pancreatic ductal adenocarcinoma compared to controls; 2.6% (22/850) vs. 1.8% (18/976) (p=0.35). CEL-HYB carriers were not more likely to report a history of pancreatitis. Patients with pancreatic cancer are not more likely than controls to be carriers of the CEL-HYB allele.

Predicting the Grade of Dysplasia of Pancreatic Cystic Neoplasms Using Cyst Fluid DNA Methylation Markers

Purpose: Pancreatic cysts are common and pose diagnostic and management challenges. Pancreatic cyst fluid markers have the potential to aid in the management of cysts with concerning imaging findings. Our aim was to evaluate cyst fluid methylated DNA markers for their accuracy for predicting the histologic grade of neoplastic pancreatic cysts.Experimental Design: Pancreatic cyst fluid samples from 183 patients (29 discovery and 154 validation) aspirated after surgical resection were analyzed for methylated DNA at selected genes (SOX17, BNIP3, FOXE1, PTCHD2, SLIT2, EYA4, and SFRP1) using methylation-specific droplet-digital PCR (dd-QMSP). Methylated DNA levels were evaluated for their accuracy at predicting the grade of dysplasia of the pancreatic cyst.Results: All six markers evaluated in the validation set could accurately distinguish high-risk cystic neoplasms (with high-grade dysplasia and/or associated invasive cancer) from low-risk cysts (lower grades of dysplasia) with accuracies from 79.8% to 83.6%. Methylated SOX17 had the highest overall accuracy as a single marker (sensitivity, 78.4%; specificity, 85.6%; accuracy 83.6%, cutoff; 25 methylated DNA molecules/μL cyst fluid). The best four-gene combination had 84.3% sensitivity, 89.4% specificity, and 88.0% accuracy at distinguishing cysts with high-grade dysplasia and/or invasive cancer from those without. All six markers were independent predictors of having invasive cancer/high-grade dysplasia after adjusting for clinical/imaging factors known to be associated with grade of dysplasia. The combination of methylated SOX17 with cytology better predicted neoplastic grade than cytology alone.Conclusions: A panel of methylated gene markers quantified by dd-QMSP can be used to predict the grade of dysplasia of pancreatic cysts. Clin Cancer Res; 23(14); 3935-44. ©2017 AACR.

Clinical relevance of EMT and stem-like gene expression in circulating tumor cells of metastatic colorectal cancer patients

Using approved methods, circulating tumor cells (CTCs) are only isolated from blood in 30%-50% of metastatic colorectal cancer (mCRC) patients. We previously validated a technique to isolate circulating tumor cells (CTCs) in a cohort of mCRC patients by combining immunomagnetic enrichment of EpCAM⁺/CD45^- cells with qRT-PCR amplification of CK20 and survivin expression. Here, we examined the prognostic utility of CTC epithelial-mesenchymal transition (EMT) and stem cell gene expression. An 8 ml blood sample was collected from 78 consecutive mCRC patients before treatment with investigational and standard chemotherapeutics. The mRNA expression of EMT (PI3Kα, Akt-2, Twist1) and stem cell (ALDH1) markers was measured. Associations between CTC gene expression and progression-free survival (PFS) and overall survival (OS) were determined using Cox regression models. Among patients without CK20 or survivin-expressing CTCs (n=17), 55% had expression of ALDH1, PI3Kα and/or Akt-2. Patients with positive CTC Akt-2 expression had a significantly shorter median PFS (3.0 versus 4.0 months) compared with those without CTC Akt-2 expression in univariable (hazard ratio (HR)=1.61; log-rank P=0.034) and multivariable analyses (HR=1.70; adjusted P=0.041). In univariable analysis, CTC ALDH1 expression was associated with shorter OS (10.0 versus 38.6 months; HR=2.04, P=0.021). Patients with CTCs expressing ALDH1, PI3Kα and/or Akt-2 had a significantly inferior PFS (3.0 versus 7.7 months; HR=1.88, P=0.015) and OS (10.0 versus 26.8+ months; HR=2.25, P=0.050) in univariable, but not multivariable, analysis.

CONCLUSIONS

CTC Akt-2 expression may serve as a clinically useful prognostic marker in mCRC patients and warrants further evaluation in prospective trials.

Abstract 1378: Generating quality control reference standards to evaluate ultrasensitive variant detection

Introduction: Ultrasensitive point mutation detection can facilitate minimal residual disease detection, early detection of cancer, and therapeutic monitoring of cancer patients. However, nearly identical mutant and wildtype molecules exhibit crosstalk with most technologies, thus producing high background levels. To evaluate technologies against each other for accurate ultrasensitive point mutation detection it is crucial to supply laboratories with reference samples of various dilutions.

Methods: We tested a series of sample mixes with digital-droplet PCR and next generation sequencing. Using linearity and accuracy as the gold standard, we empirically introduced two corrections to generate improved quality control reagents. Baseline variant allele frequency (VAF) in the parental cell line was used to correct for copy number variation of variant, while haplotype counting was used to correct technical errors (cell counting and pipetting).

Results: Correlation between the level of dilution and the measured VAF was relatively good (R2 = 0.80) when measured using ddPCR. However, correcting for the parental VAFs substantially improved the correlation (R2 = 0.97). In contrast, correlation of the cell count dilution and the measured VAF, as determined by next generation sequencing (AmpliSeq), was initially relatively poor (R2 = 0.63). However, substantial improvement in correlation was achieved by correcting for the parental VAFs (R2 = 0.94). In addition, correcting by haplotype counting alone only slightly improved accuracy in both technologies (ddPCR, from R2 = 0.80 to R2 = 0.81; AmpliSeq, from R2 = 0.63 to R2 = 0.64). Furthermore, correcting for both factors resulted in the best correlation for ddPCR-generated data (R2 = 0.99); however, introducing both corrections for AmpliSeq data did not prove more beneficial than correcting for parental VAFs alone (both corrections, R2 = 0.94 compared to parental VAF correction only, R2 = 0.94).

Conclusions: Validation of ultrasensitive variant detection requires standardized reference samples. These will also permit assessing various ultrasensitive detection technologies against one another.

Citation Format: Marija Debeljak, Lisa Haley, Derek A. Anderson, Emily M. Adams, Masaya Suenaga, Katie Beierl, Ming-Tseh Lin, Michael Goggins, Christopher D. Gocke, James R. Eshleman. Generating quality control reference standards to evaluate ultrasensitive variant detection. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1378.

Cyst Fluid Telomerase Activity Predicts the Histologic Grade of Cystic Neoplasms of the Pancreas

PURPOSE

Pancreatic cysts frequently pose clinical dilemmas. On one hand, cysts with high-grade dysplasia offer opportunities for cure, on the other hand, those with low-grade dysplasia are easily over treated. Cyst fluid markers have the potential to improve the evaluation of these cysts. Because telomerase activity is commonly activated in malignant cells, we evaluated the diagnostic performance of cyst fluid telomerase activity measurements for predicting histologic grade.

EXPERIMENTAL DESIGN

Telomerase activity was measured using telomerase repeat amplification with digital-droplet PCR in surgically aspirated cyst fluid samples from 219 patients who underwent pancreatic resection for a cystic lesion (184 discovery, 35 validation) and 36 patients who underwent endoscopic ultrasound fine-needle aspiration. Methodologic and clinical factors associated with telomerase activity were examined.

RESULTS

Telomerase activity was reduced in samples that had undergone prior thawing. Among 119 samples not previously thawed, surgical cyst fluids from cystic neoplasms with high-grade dysplasia ± associated invasive cancer had higher telomerase activity [median (interquartile range), 1,158 (295.9-13,033)] copies/μL of cyst fluid than those without [19.74 (2.58-233.6) copies/μL; P < 0.001)]. Elevated cyst fluid telomerase activity had a diagnostic accuracy for invasive cancer/high-grade dysplasia of 88.1% (discovery), 88.6% (validation), and 88.2% (merged). Among cysts classified preoperatively as having "worrisome features," cyst fluid telomerase activity had high diagnostic performance (sensitivity 73.7%, specificity 90.6%, accuracy, 86.1%). In multivariate analysis, telomerase activity independently predicted the presence of invasive cancer/high-grade dysplasia.

CONCLUSIONS

Cyst fluid telomerase activity can be a useful predictor of the neoplastic grade of pancreatic cysts. Clin Cancer Res; 22(20); 5141-51. ©2016 AACRSee related commentary by Allen et al., p. 4966.

S-1 plus nab-paclitaxel is a promising regimen for pancreatic cancer in a preclinical model

OBJECTIVES

The aim of this study was to investigate the efficacy and mechanism of action of combined S-1 and nab-paclitaxel in pancreatic cancer.

METHODS

Three human pancreatic cancer cell lines were treated with S-1, nab-paclitaxel, alone or in combination. Mice bearing subcutaneous xenograft of the cell line, PANC-1, were treated with the same drugs.

RESULTS

The growth-inhibitory effect of combined S-1 and nab-paclitaxel was greater than that of the individual drugs, and the combination index value indicated that S-1 and nab-paclitaxel had a synergistic effect in vitro. The combination of S-1 and nab-paclitaxel showed greater efficacy in vivo than monotherapy, and the growth-inhibitory effect was significantly greater when compared with the controls (P = 0.009), although no significant reduction in body weight was observed. Fractional tumor volume analysis indicated that the combination had a synergistic effect. Tumor stroma staining with α-smooth muscle actin was significantly decreased by nab-paclitaxel (P < 0.001) while the number of CD31-stained microvessel lumina was significantly increased by the combination therapy when compared with the control (P = 0.046).

CONCLUSIONS

S-1 and nab-paclitaxel had a synergetic effect in preclinical studies with good tolerability, and may play a role in stromal depletion and tumor angiogenesis. J. Surg. Oncol. 2016;113:413-419. © 2016 Wiley Periodicals, Inc.