Determination of circulating tumor cells by flow cytometry in the bladder cancer patients

Bladder cancer is one of the most common malignancies of the urinary system and causes to 15,500 deaths every year. The worldwide age standardized rate (ASR) is 10.1 per 100 000 for men and 2.5 per 100 000 for women. Non-muscle invasive disease is usually treated with transurethral resection of bladder tumor (TUR-BT), depending on the depth of invasion and tumor grade. Radical cystectomy (RC) with or without perioperative chemotherapy is the gold standard treatment in muscle invasive and recurrent high-grade non-muscle invasive urothelial carcinoma of the bladder (UCB). The deaths in most cancer are dependent on metastasis to distant organs due to disease dissemination by Circulating Tumor Cells (CTCs) spread out from the primary tumor. Metastasis is related to the presence and number of CTCs in the vasculature. The presence of CTCs preoperatively was an independent adverse prognostic factor for cancer-free survival in patients undergoing cystectomy. Highly sensitive, real-time monitoring of CTCs can be carried out with flow cytometry using diverse detection systems without the need of extracting blood samples. The current study aimed to detect of CTCs in 7.5 mL blood sample in bladder cancer patients treated with TUR or RC. CTCs were detected in peripheral blood of 10 bladder cancer patients with flow cytometry using biomarkers EpCAM, CK 14, 15, 16, 19 and CK 7, 8 for positive selection and CD45 for negative selection. The blood samples obtained before and after operation were studied in 5 out of 10 patients. The number of CTCs decreased significantly on patients (Z=2.032; p=0.042) after the operation. No CTCs were detected in control group.