Circulating Cell-Free DNA Levels in Patients with Metastatic Renal Cell Carcinoma.
BACKGROUND
Limited data about biomarkers are available to predict the outcomes of targeted therapy in metastatic renal cell carcinoma (mRCC). Circulating cell-free DNA (CFD) is elevated in various cancers.


PATIENTS AND METHODS
We performed a prospective study of patients with mRCC who received targeted therapy in the Soroka Medical Center between 2013 and 2015. CFD levels were measured using a simple fluorometric assay. Blood samples for CFD were collected before treatment and at weeks 1, 4, 12, 18, and 24 of treatment. The normal cut-off level of CFD was defined as 800 ng/ml. The association of CFD with objective response, progression-free survival (PFS), and overall survival was tested, with adjustment for known confounding risk factors.


RESULTS
A total of 23 patients were included; 18 were treated with first-line therapy and 5 with second- and third-line therapies. Patients with normal pretreatment CFD level had a better PFS versus patients with increased levels (p = 0.023). In multivariate analysis, factors associated with PFS were pretreatment CFD levels (p = 0.020) and Heng risk (p = 0.006).


CONCLUSIONS
Elevated pretreatment CFD levels measured using a simple fluorometric assay may be associated with a worse PFS in patients with mRCC. A larger prospective study is warranted in order to validate our observation.
['Rouvinov|Keren|K|', 'Mermershtain|Wilmosh|W|', 'Dresler|Hadas|H|', 'Ariad|Samuel|S|', 'Riff|Reut|R|', 'Shani-Shrem|Noa|N|', 'Keizman|Daniel|D|', 'Neulander|Endre Z|EZ|', 'Douvdevani|Amos|A|']
D000368:Aged D000369:Aged, 80 and over D000077784:Axitinib D002292:Carcinoma, Renal Cell D000073888:Cell-Free Nucleic Acids D003131:Combined Modality Therapy D018572:Disease-Free Survival D000068338:Everolimus D005260:Female D005500:Follow-Up Studies D006801:Humans D007093:Imidazoles D007191:Indazoles D007211:Indoles D007680:Kidney Neoplasms D008297:Male D008875:Middle Aged D009392:Nephrectomy D011237:Predictive Value of Tests D011446:Prospective Studies D011743:Pyrimidines D011758:Pyrroles D013449:Sulfonamides D000077210:Sunitinib
Circulating cell-free DNA Targeted therapy Treatment Response Marker Renal cell cancer