Transurethral bladder tumor resection can cause seeding of cancer cells into the bloodstream.

PURPOSE: 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. MATERIALS AND 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.

Circulating tumor cells in patients with advanced urothelial carcinoma of the bladder: Association with tumor stage, lymph node metastases, FDG-PET findings, and survival.

BACKGROUND: There are currently no methods in clinical use that can detect early systemic dissemination of urothelial tumor cells. OBJECTIVE: To evaluate measurement of circulating tumor cells (CTCs) as a biomarker for disseminated disease in patients with advanced bladder cancer. DESIGN, SETTING, AND PARTICIPANTS: Between March 2013 and October 2015, 88 patients were prospectively included in the study: 78 were scheduled for radical cystectomy (RC) ± perioperative chemotherapy and 10 treated with palliative chemotherapy. The CellSearch CTC test was further assessed in this context by investigating expression of epithelial cell adhesion molecule (EpCAM) in primary tumors obtained at cystectomy from an independent cohort of 409 patients. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Presence of CTCs was tested for association with tumor stage, lymph node metastases, metastatic disease on [18 F]-fluorodeoxyglucose-positron emission tomography (FDG-PET), and cancer-specific and progression-free survival. RESULTS: CTCs were detected in 17/88 patients (19%). In 61 patients who underwent FDG-PET-computed tomography (CT), a statistically significant association with presence of CTCs was found for radiological metastatic disease but not for normal PET-CT results (12/35 [34%] vs. 2/26 [8%], P = 0.014). After a median follow-up time of 16.5 months (95% CI: 9.6-21.4), presence of CTCs was associated with an increased risk of progression among patients treated with RC with or without perioperative chemotherapy (n = 75, P = 0.049). A multivariate analysis adjusted for clinical tumor stage, clinical lymph node status, and age showed that CTCs were an independent marker of progression (n = 75; hazard ratio = 2.78; 95% CI: 1.005-7.69; P = 0.049) but not of cancer-specific death (P = 0.596). In 409 cystectomised patients, more than 392 (96%) of the bladder tumors expressed EpCAM. CONCLUSIONS: CTCs were present in 19% of patients with advanced urothelial tumors and were associated with metastatic disease on FDG-PET-CT and with increased risk of disease progression after RC. A significant portion of urothelial cancer cells do express EpCAM and can thus be identified using EpCAM-antigen-based CTC detection methods.