title: Transurethral bladder tumor resection can cause seeding of cancer cells into the bloodstream.
abstract: OBJECTIVE
  Transurethral bladder tumor resection is the initial diagnostic procedure for bladder cancer. Hypothetically tumor resection could induce seeding of cancer cells into the circulation and subsequent metastatic disease. In this study we ascertain whether transurethral bladder tumor resection induces measurable seeding of cancer cells into the vascular system.
  
  
  METHODS
  Patients newly diagnosed with suspected invasive bladder cancer and planned for transurethral resection of bladder tumor in 2012 to 2013 were enrolled in the study. Before transurethral bladder tumor resection a vascular surgeon placed a venous catheter in the inferior vena cava via the femoral vein. Blood samples were drawn before and during the resection from the inferior vena cava and a peripheral vein, and analyzed for circulating cancer cells using the CellSearch® system. The number of circulating tumor cells identified was compared in preoperative and intraoperative blood samples.
  
  
  RESULTS
  The circulating tumor cell data on 16 eligible patients were analyzed. In 6 of 7 positive inferior vena cava samples (86%) the number of circulating tumor cells was increased intraoperatively (28 vs 9, 28 vs 0, 28 vs 5, 3 vs 0, 4 vs 0, 1 vs 0), and results were similar, although less conclusive, for the corresponding peripheral vein samples.
  
  
  CONCLUSIONS
  Our study confirms that tumor cells can be released into the circulation during transurethral bladder tumor resection. It is currently unknown whether this will increase the risk of metastatic disease.
authors.affiliation: Department of Urology, Clinical Sciences, Lund University, Skåne University Hospital, Malmö, Sweden.
authors.forename: Helgi
authors.initials: H
authors.lastname: Engilbertsson
authors.affiliation: Department of Oncology, Clinical Sciences, Lund University, Skåne University Hospital, Malmö, Sweden.
authors.forename: Kristina E
authors.initials: KE
authors.lastname: Aaltonen
authors.affiliation: Department of Vascular Surgery, Clinical Sciences, Lund University, Skåne University Hospital, Malmö, Sweden.
authors.forename: Steinarr
authors.initials: S
authors.lastname: Björnsson
authors.affiliation: Department of Vascular Surgery, Clinical Sciences, Lund University, Skåne University Hospital, Malmö, Sweden.
authors.forename: Thorarinn
authors.initials: T
authors.lastname: Kristmundsson
authors.affiliation: Department of Urology, Clinical Sciences, Lund University, Skåne University Hospital, Malmö, Sweden.
authors.forename: Oliver
authors.initials: O
authors.lastname: Patschan
authors.affiliation: Department of Surgery, Clinical Sciences, Lund University, Skåne University Hospital, Malmö, Sweden.
authors.forename: Lisa
authors.initials: L
authors.lastname: Rydén
authors.affiliation: Department of Urology, Clinical Sciences, Lund University, Skåne University Hospital, Malmö, Sweden. Electronic address: sigurdur.gudjonsson@skane.se.
authors.forename: Sigurdur
authors.initials: S
authors.lastname: Gudjonsson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015653:Cystectomy / Q000009:adverse effects* / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009366:Neoplasm Seeding; D009360:Neoplastic Cells, Circulating; D014521:Urethra; D001749:Urinary Bladder Neoplasms / Q000097:blood / Q000473:pathology / Q000601:surgery*
keywords: circulating; neoplasm metastasis; neoplastic cells; urinary bladder neoplasms