Citations

Abstract Background: Published evidence indicates that individual use of metformin and statin is associated with reduced cancer mortality. However, their differential and joint effects on pancreatic cancer survival are inconclusive. Methods: We identified a large population-based cohort of 12,572 patients ages 65 years or older with primary pancreatic ductal adenocarcinoma (PDAC) diagnosed between 2008 and 2011 from the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database. Exposure to metformin and statins was ascertained from Medicare Prescription Drug Event files. Cox proportional hazards models with time-varying covariates adjusted for propensity scores were used to assess the association while controlling for potential confounders. Results: Of 12,572 PDAC patients, 950 (7.56%) had used metformin alone, 4,506 (35.84%) had used statin alone, and 2,445 (19.45%) were dual users. Statin use was significantly associated with improved overall survival [HR, 0.94; 95% confidence interval (CI), 0.90–0.98], and survival was more pronounced in postdiagnosis statin users (HR, 0.69; 95% CI, 0.56–0.86). Metformin use was not significantly associated with overall survival (HR, 1.01; 95% CI, 0.94–1.09). No beneficial effect was observed for dual users (HR, 1.00; 95% CI, 0.95–1.05). Conclusions: Our findings suggest potential benefits of statins on improving survival among elderly PDAC patients; further prospective studies are warranted to corroborate the putative benefit of statin therapy in pancreatic cancer. Impact: Although more studies are needed to confirm our findings, our data add to the body of evidence on potential anticancer effects of statins. Cancer Epidemiol Biomarkers Prev; 26(8); 1225–32. ©2017 AACR.

Vascularized lymph node (VLN) transfer has been of high interest in the past decade for the treatment of lymphedema, since it has been shown to be effective in reducing limb volumes, decreasing infectious episodes and improving quality of life. Multiple donor sites have been described in the quest for the optimal one. Herein, we describe a novel lymph node flap option based on the ileocolic artery and vein. The ileocecal vascularized lymph node (IC‐VLN) flap was used in the management of a 33‐year‐old male patient with lower extremity lymphedema secondary to left inguinal trauma. The patient had previously underwent a pedicled omentum flap transposition with minimal improvement in limb size and persistent episodes of infection. At 15 month follow‐up, the IC‐VLN flap improved the lymphatic drainage in the affected limb with a mean limb circumference reduction rate of 26.3%. No donor site complications or further episodes of infection were noted. According to our findings, the IC‐VLN flap may be another option for VLN transfer in very selected cases. Nevertheless, larger series with a longer follow‐up are required to analyze the efficacy and long‐term results of this flap.

Abstract Purpose: Androgen receptor (AR) variant AR-V7 is a ligand-independent transcription factor that promotes prostate cancer resistance to AR-targeted therapies. Accordingly, efforts are under way to develop strategies for monitoring and inhibiting AR-V7 in castration-resistant prostate cancer (CRPC). The purpose of this study was to understand whether other AR variants may be coexpressed with AR-V7 and promote resistance to AR-targeted therapies. Experimental Design: We utilized complementary short- and long-read sequencing of intact AR mRNA isoforms to characterize AR expression in CRPC models. Coexpression of AR-V7 and AR-V9 mRNA in CRPC metastases and circulating tumor cells was assessed by RNA-seq and RT-PCR, respectively. Expression of AR-V9 protein in CRPC models was evaluated with polyclonal antisera. Multivariate analysis was performed to test whether AR variant mRNA expression in metastatic tissues was associated with a 12-week progression-free survival endpoint in a prospective clinical trial of 78 CRPC-stage patients initiating therapy with the androgen synthesis inhibitor, abiraterone acetate. Results: AR-V9 was frequently coexpressed with AR-V7. Both AR variant species were found to share a common 3′ terminal cryptic exon, which rendered AR-V9 susceptible to experimental manipulations that were previously thought to target AR-V7 uniquely. AR-V9 promoted ligand-independent growth of prostate cancer cells. High AR-V9 mRNA expression in CRPC metastases was predictive of primary resistance to abiraterone acetate (HR = 4.0; 95% confidence interval, 1.31–12.2; P = 0.02). Conclusions: AR-V9 may be an important component of therapeutic resistance in CRPC. Clin Cancer Res; 23(16); 4704–15. ©2017 AACR.

ABSTRACT Eighty Gram-negative bacilli (54 Enterobacteriaceae and 26 nonfermenting Gram-negative bacilli) obtained from multiple institutions in the United States were distributed in a blinded manner to seven testing laboratories to compare their performance of a test for detection of carbapenemase production, the Carba NP test. The Carba NP test was performed by all laboratories, following the Clinical and Laboratory Standards Institute (CLSI) procedure. Site-versus-site comparisons demonstrated a high level of consistency for the Carba NP assay, with just 3/21 site comparisons yielding a difference in sensitivity ( P < 0.05). Previously described limitations with bla OXA-48-like carbapenemases and bla OXA carbapenemases associated with Acinetobacter baumannii were noted. Based on these data, we demonstrate that the Carba NP test, when implemented with the standardized CLSI methodology, provides reproducible results across multiple sites for detection of carbapenemases.

175 Background: Genome and transcriptome aberrations associated with primary resistance to abiraterone acetate/prednisone (AA/P) in mCRPC are not known. In a prospective trial (NCT#01953640) we assessed whole-exome and RNA-seq based aberrations in metastases of CRPC stage patients (pts) for identifying markers associated with primary resistance to AA/P. Methods: Whole-exome and RNA-seq of biopsies from metastases was performed followed by analyses for association between genomic aberrations & primary resistance. Primary resistance was defined by progression on AA/P after 12-weeks of therapy(non-responders) using PSA, RECIST, bone scan and symptom criteria (per PCWG2). Gene network analysis was performed in genes mutated more frequently in non-responders, and also in genes that were differentially expressed between non-responders and responders and a “risk ratio” (RR) was calculated thereof. Results: Between 6/2013 & 8/2015, 92 pts were enrolled of which 82 had complete whole-exome, RNA-seq and 12-week outcome data available for analysis. Median age was 72.5 yrs (IQR: 68.5-78); median PSA-18 ng/ml (IQR: 8.1- 46.6). At 12-weeks 33/82 had progressed. Using the RR of 2 as threshold, we identified 113 and 292 genes that were more frequently mutated in non-responders & responders respectively. Among the 113 genes, OBSCN, ADAM21, LPHN3, DOCK10 ( P = 0.08, RR= inf) & USP42 ( P = 0.16, RR = 5.71) were the top candidates.Gene network analysis revealed that in non-responders, genes involved in the Wnt/β-catenin pathway were frequently mutated and negative regulators of Wnt pathway ( DKK4, SFRP2 & LRP6) were also frequently deleted. Gene expression analyses revealed the expression levels of Wnt/β-catenin pathway inhibitors were significantly reduced while expression levels of cell cycle regulatory genes were significantly increased in non-responders. Conclusions: In this study we observed Wnt/β-catenin pathway activation to be associated with primary AA/P resistance. This finding offers a potential for the development of predictive biomarkers and modulation of targeted pathways to overcome AA/P resistance. Clinical trial information: NCT# 01953640.

152 Background: Plasma cfDNA ARcopy number variations (CNV) have been suggested to have prognostic significance in mCRPC stage. We compared plasma AR amplification ( ARamp) with CTC counts (the only FDA approved prognostic marker in mCRPC stage) in a prospective trial of patients (pts) progressing on androgen deprivation therapy. Methods: Plasma and CTC counts were obtained concurrently as part of a prospective clinical trial in mCRPC stage pts initiating abiraterone acetate (NCT# 01953640). Plasma cfDNA was purified using DNA Blood Mini Kit (Qiagen, Valencia, CA) and AR CNVs were detected using QuantStudio3D digital PCR system (Life Technologies, Carlsbad, CA, USA). CTC enumeration was performed using the FDA cleared CellSearch platform. The distributions of overall survival (OS) time based on ARamp status and CTC counts ( < 5 vs ≥ 5 cells) were estimated using the Kaplan-Meier method. Log-rank tests were used to test association of ARamp status and CTC counts with overall survival (OS). Univariate and multivariate logistic regression models and ROC evaluated association of OS at 24 months by ARamp status and CTCs ≥ 5. Results: Between 05/2013 and 09/2015, 92 pts were enrolled of which complete CTC, plasma and outcome data was available for 70 pts. Median age of the cohort (range) was 72 yrs (39-91); Median PSA–16.2 ng/ml (range: 0.9-2026.0); Median CTC count was 2.0 (range: 0-372); 58/70 pts had bone metastases; 38/70 had high volume and 32/70 had low volume metastatic disease at the time of sample collection. The median (range) follow up time at the time of this analysis was: 26.5 (7.9-37.0) months at which time 28/70 patients had died. ARamp was present in 19/70 pts while 51/70 did not have amplification. 24/70 had CTCs ≥ 5. A significant association of increased ARamp status with OS (p < 0.0001, log-rank test; AUC: 0.66) as well as with CTC counts ≥ 5 (p = 0.001, log-rank test; AUC: 0.67) was observed. Combining CTC status and plasma ARamp status the AUC was 0.75. Conclusions: Plasma cfDNA ARamp status and CTC counts have comparable and clinically meaningful prognostic marker value in mCRPC stage patients.

260 Background: The purpose of this study was to evaluate cell free nucleic acid based biomarkers for prognosis in mCRPC stage. Methods: Uniformly collected blood from mCRPC patients was processed for plasma which was used for exosomal RNA extraction. RNA sequencing was applied to examine microRNA (miRNA) profiles initially in a discovery cohort of 23 mCRPC patients. The sequences from fastq files were mapped to human miRBase (release 19) for known miRNA read counts. A software package (miRDeep2) was used for novel miRNA prediction. Cox regression was used for association of candidate miRNAs with overall survival (OS), defined as time from development of mCRPC to death or last follow up after adjusting for Gleason Score (GS) and time on androgen deprivation (AD) for hormone sensitive disease. miRNAs significantly associated with OS (FDR<0.05) were then validated in an independent cohort of 100 mCRPC subjects using univariate Cox regression. Results: RNA sequencing generated >10 million mappable reads per specimen in the discovery cohort. Among these reads ~50% were known miRNAs which included 1237 unique RNA sequences. Due to low abundance of most RNA transcripts, only miRNAs (n=250) with >/= 32 reads (on average) were analyzed. Four mRNAs (miR-1290, -1246, -375 and a predicted miRNA on chr. 12) were associated with OS(FDR<0.05). These were evaluated as prognotic markers in the independent cohort (N=100) using real time RT-PCR. Median time on AD for this cohort prior to progression to mCRPC was 35.7 (range: 3.5-136) months; median GS was 7; median follow up after mCRPC development was 12.5 (1-41) months at which time 28 patients had died. Elevated expression for miR-1290 and -375 were associated with shorter OS after adjusting for GS and AD time with a Hazard Ratio (HR) for miR-375 of 1.19 (CI: 1.006-1.18); (p=0.04) and a HR for miR1290 of 1.58 (CI:1.01-2.4); (p=0.04). A stronger association with shorter OS was observed for elevated expression of both miRs-HR of 2.02 (CI: 1.1-3.6) (p=0.01). Conclusions: Blood-based nucleic acid assays are easily accessible for biomarker development in mCRPC. Results from this study suggest specific exosomal miRs are of prognostic value in mCRPC and should be validated in larger cohorts.