Background: Bladder cancer recurrence following cystectomy remains a significant cause of bladder cancer-specific mortality. Residual cancer cells (RCCs) contribute to cancer recurrence due either to tumor spillage or undetectable pre-existing micrometastatic tumor clones. We sought to detect and quantify RCCs in pelvic washing using ultra-deep targeted sequencing (UTS) and compare the levels of RCCs with clinical variables and cancer recurrence. Methods: 17 patients underwent robotic-assisted radical cystectomy (RARC) with primary tumor specimen available. All tumors had negative surgical margins. Pelvic washes and blood were collected intra-operatively: before RARC, after RARC, after pelvic lymph node dissection (PLND), and in the suction fluid collected during the procedure. A two-step sequencing, including whole-exome sequencing (WES) followed by UTS (>50,000X), was used to quantify RCCs in each sample. Eight patients were excluded due to sample quality issues. The final analysis cohort included nine patients. RCC level was quantified for each sample as the relative cancer cell fraction (RCCF), and compared between different time points. The peak RCCF (pRCCF) of each patient was correlated with clinical and pathological variables. Results: RCCs were detected in approximately half of the pelvic washing specimens during or after RARC, but not before it. Higher levels of RCCs were associated with aggressive variant histology and cancer recurrence. Verifying the feasibility of using RCCs as a novel biomarker for recurrence requires larger cohorts. Conclusions: Detection of RCCs in intra-operative peritoneal washes of bladder cancer patients undergoing radical cystectomy may represent a robust biomarker of tumor aggressiveness and metastatic potential.

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mortality. By using the conditions independently associated with competing mortality in both samples a combined mortality index was created which stratified the patients into risk groups with 0% 10-year competing mortality in the lowest and approximately 50% in the highest risk classes.CONCLUSIONS: This easily applicable mortality index based on age, ASA class, smoking status and the presence of the conditions angina pectoris, chronic lung disease and diabetes mellitus may be used to predict competing mortality in candidates for radical cystectomy or radical prostatectomy.

High LASP1 expression correlated with metastatic recurrence rate between patients. The LASP1 expression is higher in UC1 and T24 cells than in UC13 and UC6 cells. Knockdown of LASP1 using siRNA inhibited cell growth, and was accompanied by an increase in p21 and p27, and a decreased of cyclin D1. Flow cytometry revealed that LASP1 knockdown induced G1 arrest. Conversely, stable LASP1 overexpression drove cell growth with an increase of cyclin D1 in UC6 and UC3 cells. The treatment of CDDP and GEM induced LASP1 expression in Western Blotting. Furthermore, compared with parental cell line, LASP1 is higher in T24 CDDP-R and RT112 CDDP-R cells than in parental cells. LASP1 ASO inhibited cell growth in RT112 CDDP-R and T24 CDDP-R cells. In the orthotopic bladder cancer model, systemic LASP1 ASO administration to athymic nude mice delayed tumor progression in T24 CDDP-R cells.CONCLUSIONS: These data revealed that LASP1 inhibition might be as a promising novel therapeutics modality in the treatment of chemoresistant bladder cancer.