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

Abstract

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. 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. 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. 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.