Increased level and fragmentation of plasma circulating cell-free DNA are diagnostic and prognostic markers for renal cell carcinoma

// Yoshiyuki Yamamoto 1 , Motohide Uemura 1, 2 , Kosuke Nakano 1 , Yujiro Hayashi 1 , Cong Wang 1 , Yu Ishizuya 1 , Toshiro Kinouchi 1 , Takuji Hayashi 1 , Kyosuke Matsuzaki 1 , Kentaro Jingushi 2 , Taigo Kato 1 , Atsunari Kawashima 1 , Takeshi Ujike 1 , Akira Nagahara 1 , Kazutoshi Fujita 1 , Ryoichi Imamura 1 and Norio Nonomura 1 1 Department of Urology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan 2 Department of Therapeutic Urologic Oncology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan Correspondence to: Motohide Uemura, email: uemura@uro.med.osaka-u.ac.jp Keywords: circulating cell-free DNA; renal cell carcinoma; plasma; level; fragment size Received: December 14, 2017      Accepted: March 11, 2018      Published: April 17, 2018 ABSTRACT Background: Reliable biomarkers for renal cell carcinoma (RCC) have yet to be found. Circulating cell-free DNA (cfDNA) is an emerging resource for the diagnosis and prognosis of various cancers. This study aims to identify novel blood biomarkers for RCC. Materials And Methods: Plasma cfDNA was extracted from RCC patients ( n = 92) and healthy controls ( n = 41). Levels of cfDNA were determined using quantitative real-time PCR of ACTB as the target gene, and cfDNA fragment size was measured using a microfluidics-based platform. Diagnostic potential was assessed using receiver operating characteristic (ROC) and logistic regression analysis, and prognostic potential was evaluated using log-rank test. Results: Median levels of cfDNA from RCC patients were significantly higher than those from healthy controls (3803 vs 2242 copies/ml, p < 0.001). Median fragment sizes of cfDNA in RCC patients were shorter than those in healthy controls (170 vs 171 bp, p = 0.052). To evaluate level of cfDNA as a diagnostic tool for RCC, ROC curve analysis revealed a sensitivity of 63.0% and a specificity of 78.1%. Multivariate analysis indicated that age, gender and the level of cfDNA were significantly associated with the presence of RCC ( p < 0.001, p = 0.013, p < 0.001, respectively). Additionally, shorter cfDNA fragment size was negatively associated with progression-free survival ( p = 0.006). Conclusions: Our study demonstrates the diagnostic and prognostic potential of plasma cfDNA as a biomarker for RCC.