title: Liquid Biopsy Analysis of FGFR3 and PIK3CA Hotspot Mutations for Disease Surveillance in Bladder Cancer.
abstract: Disease surveillance in patients with bladder cancer is important for early diagnosis of progression and metastasis and for optimised treatment.
  
  
  
  To develop urine and plasma assays for disease surveillance for patients with FGFR3 and PIK3CA tumour mutations.
  
  
  
  Droplet digital polymerase chain reaction (ddPCR) assays were developed and tumour DNA from two patient cohorts was screened for FGFR3 and PIK3CA hotspot mutations. One cohort included 363 patients with non-muscle-invasive bladder cancer (NMIBC). The other cohort included 468 patients with bladder cancer undergoing radical cystectomy (Cx). Urine supernatants (NMIBC n=216, Cx n=27) and plasma samples (NMIBC n=39, Cx n=27) from patients harbouring mutations were subsequently screened using ddPCR assays.
  
  
  
  Progression-free survival, recurrence-free survival, and overall survival were measured. Fisher's exact test, the Wilcoxon rank-sum test and Cox regression analysis were applied.
  
  
  
  In total, 36% of the NMIBC patients (129/363) and 11% of the Cx patients (44/403) harboured at least one FGFR3 or PIK3CA mutation. Screening of DNA from serial urine supernatants from the NMIBC cohort revealed that high levels of tumour DNA (tDNA) were associated with later disease progression in NMIBC (p=0.003). Furthermore, high levels of tDNA in plasma samples were associated with recurrence in the Cx cohort (p=0.016). A positive correlation between tDNA levels in urine and plasma was observed (correlation coefficient 0.6). The retrospective study design and low volumes of plasma available for analysis were limitations of the study.
  
  
  
  Increased levels of FGFR3 and PIK3CA mutated DNA in urine and plasma are indicative of later progression and metastasis in bladder cancer.
  
  
  
  Urine and plasma from patients with bladder cancer may be monitored for diagnosis of progression and metastasis using mutation assays.
authors.affiliation: Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Emil
authors.initials: E
authors.lastname: Christensen
authors.affiliation: Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Karin
authors.initials: K
authors.lastname: Birkenkamp-Demtröder
authors.affiliation: Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Iver
authors.initials: I
authors.lastname: Nordentoft
authors.affiliation: Department of Pathology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Høyer
authors.affiliation: Department of Pathology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands.
authors.forename: Kirstin
authors.initials: K
authors.lastname: van der Keur
authors.affiliation: Department of Pathology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands.
authors.forename: Kim
authors.initials: K
authors.lastname: van Kessel
authors.affiliation: Department of Pathology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands.
authors.forename: Ellen
authors.initials: E
authors.lastname: Zwarthoff
authors.affiliation: Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Mads
authors.initials: M
authors.lastname: Agerbæk
authors.affiliation: Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Torben Falck
authors.initials: TF
authors.lastname: Ørntoft
authors.affiliation: Department of Urology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Jørgen Bjerggaard
authors.initials: JB
authors.lastname: Jensen
authors.affiliation: Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark. Electronic address: lars@clin.au.dk.
authors.forename: Lars
authors.initials: L
authors.lastname: Dyrskjøt
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics* / Q000652:urine; D000074141:Circulating Tumor DNA / Q000097:blood / Q000235:genetics* / Q000652:urine; D058534:Class I Phosphatidylinositol 3-Kinases / Q000097:blood / Q000235:genetics* / Q000652:urine; D015653:Cystectomy; D004252:DNA Mutational Analysis; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D053208:Kaplan-Meier Estimate; D000073890:Liquid Biopsy; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D051498:Receptor, Fibroblast Growth Factor, Type 3 / Q000097:blood / Q000235:genetics* / Q000652:urine; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000097:blood / Q000235:genetics* / Q000601:surgery / Q000652:urine
chemical_list: D014408:Biomarkers, Tumor; D000074141:Circulating Tumor DNA; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; C496365:FGFR3 protein, human; D051498:Receptor, Fibroblast Growth Factor, Type 3
keywords: Biomarker; Cell-free DNA; Droplet digital polymerase chain reaction; FGFR3; Liquid biopsy; PIK3CA; Personalised analysis