Yaskiv, Oksana

631 Background: For most clear cell renal cell carcinoma (ccRCC) patients with early stage disease, surgical resection offers definitive cure. However, for the small percentage of tumors that metastasize, analyzing gene expression profiles from the primary site at the time of nephrectomy can serve as a model to understand the molecular aberrations behind a metastatic phenotype. Differences in gene expression profiles between patients with Stage I and II ccRCC who experience metastasis versus patients who maintain cure after surgery may help elucidate significant molecular targets and stratify patients at higher risk for metastasis. Methods: Nineteen Stage I and twenty Stage II ccRCC tumors preserved in FFPE blocks after nephrectomy were included in this study. Patients were matched for age, gender, tumor size and grade. In both stages, approximately half the patients that experienced metastasis within 5 years of surgery were part of the experimental group, whereas the control group had > 5 years of follow-up without evidence of disease. Extracted RNA for Stage I patients was sequenced using Illumina TruSeq RNA Access Library. Gene counts were assessed by ht-seq counts and differential expression using DESeq2. Significant genes found were validated in the Stage II group using RT-qPCR. Results: In the Stage I experimental group, statistically significant upregulation of several genes associated with unfavorable prognosis in RCC were found: COL1A1, NUMBL, and STEAP3. Random forest classification accurately separated Stage I control versus experimental patients based on expression of COL1A1. Affected genes were consistent with molecular changes seen in TCGA analysis. In the Stage II group, a double-blinded analysis correctly identified the clinical outcome for the majority of the patients using qPCR expression of COL1A1, NUMBL, and STEAP3. Conclusions: Differences in gene expression profiles harbored in the primary site of early stage ccRCC may be employed to predict patients at high risk for developing metastasis. Validating these findings in a larger study carries the potential to better understand mechanisms of metastasis and identify an at risk cohort of patients with early stage disease.

Objectives To investigate the impact of implementing magnetic resonance imaging (MRI) and ultrasonography fusion technology on biopsy and prostate cancer (PCa) detection rates in men presenting with clinical suspicion for PCa in the clinical practice setting. Patients and Methods We performed a review of 1 808 consecutive men referred for elevated prostate‐specific antigen (PSA) level between 2011 and 2014. The study population was divided into two groups based on whether MRI was used as a risk stratification tool. Univariable and multivariable analyses of biopsy rates and overall and clinically significant PCa detection rates between groups were performed. Results The MRI and PSA‐only groups consisted of 1 020 and 788 patients, respectively. A total of 465 patients (45.6%) in the MRI group and 442 (56.1%) in the PSA‐only group underwent biopsy, corresponding to an 18.7% decrease in the proportion of patients receiving biopsy in the MRI group ( P < 0.001). Overall PCa (56.8% vs 40.7%; P < 0.001) and clinically significant PCa detection (47.3% vs 31.0%; P < 0.001) was significantly higher in the MRI vs the PSA‐only group. In logistic regression analyses, the odds of overall PCa detection (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.29–2.35; P < 0.001) and clinically significant PCa detection (OR 2.04, 95% CI 1.48–2.80; P < 0.001) were higher in the MRI than in the PSA‐only group after adjusting for clinically relevant PCa variables. Conclusion Among men presenting with clinical suspicion for PCa, addition of MRI increases detection of clinically significant cancers while reducing prostate biopsy rates when implemented in a clinical practice setting.