Systemic dissemination of tumor cells during transurethral resection in patients with bladder tumor and its clinical relevance: A follow up study.

OBJECTIVE: Tumor cells are shed during transurethral resection of bladder tumor (TURBT) and form the basis for use of single dose immediate chemotherapy instillation to reduce recurrences. Systemic dissemination of these cells along with the irrigation fluid is also possible but not consistently proven. In this study, we evaluated such dissemination of tumor cells into the circulation during TURBT and its clinical impact.

METHODS: Patients with primary presentation of bladder tumor who underwent TURBT were included. Peripheral venous blood samples before and after TURBT were analyzed for circulating tumor cells (CTCs) using flow-cytometry. A CD45 negative cell with positive expression of cytokeratin 18, 19, and EpCam was defined as CTC. The CTC counts, pre and post TURBT, were compared and correlated with final histopathology. The patients were also followed up for any local and/or systemic recurrences.

RESULTS: Nine (16.98%) out of 53 patients developed a measurable rise in CTCs after TURBT. All of these patients had high grade and muscle invasive disease. Overall, a measurable rise in CTCs was seen in 9 out of 17 (52.94%) patients with muscle invasive disease. There was no difference in the clinico-pathological stage or the status of cystectomy and/or chemotherapy between those who did or did not show a rise in CTCs. On follow up, 7 patients with muscle invasive disease developed local and/or systemic recurrences and the rise in CTCs was not found to be associated with adverse oncological outcomes.

CONCLUSIONS: This study confirms the hypothesis of inadvertent dissemination of tumor cells into the circulation during TURBT, especially in patients with high grade and muscle invasive disease. The long-term oncological impact of such dissemination remains to be confirmed.