Relationship Between Methods of Bladder Tumor Extraction and Local Recurrence Rate

According to clinical guidelines, endoscopic surgery (mono- or bipolar TURBT, laser resection, en bloc resection) is a standard treatment option for patients with primary non-muscle invasive bladder cancer (NMIBC) (excluding carcinoma in-situ). However, more than half of patients will experience local recurrence after surgery. It is believed that one of the main causes for this local recurrence is the reimplantation of tumor cells during endoscopic surgery. It is crucial to limit contact between the resected tumor and the bladder wall during the operation and to extract the specimen as quickly as possible. In the case of a small tumor, the surgeon can immediately remove it using an endoscopic instrument. There are a number of methods available for removing large tumors, but it is not yet clear which one is most optimal. Therefore, comparing the oncological results from evacuating bladder tumors using various methods is very timely. Based on the previously mentioned studies, the investigators assume that the rate of bladder cancer relapse out site of the resection area would be lower in the morcellation group compared with piecemeal resection of the tumor. In order to prove this, the investigators plan to conduct a randomized study comparing the relapse rate in these two groups.

Patients scheduled for laser en bloc tumor resection with subsequent morcellation of exophytic part of the tumor

Patients scheduled for piecemeal bladder tumor TUR with subsequent removing of tissue using the instrument loop or Janet's syringe.

Laser en bloc resection with subsequent tumor morcellation will be performed. This tissue will be sent for histology in order to estimate the histological subtype and differentiation grade. Next stage laser resection of the tumor basis will be performed with subsequent histology to determine the depth of invasion and the status of surgical margin.

Tumor piecemeal resection will be performed with electric loop. Then fragments of the tumor will be removed by the loop or Janet's syringe. Fragments from the base of the tumor will be sent separately in order to assess which stage the tumor is at and its surgical margin status.

Absence of the tumor out of the place of resection of the bladder wall during the follow-up cystoscopy

Inclusion Criteria: Patients scheduled for endoscopic bladder tumor removal Non-muscle invasive bladder cancer on contrast-enhanced MRI or CT (stage cT1N0M0 and lower) Diameter of tumor >3cm Exclusion Criteria: Patient refused to participate in the trial Multiple (more than 2) bladder tumors Previous cold-cup biopsy or any other surgery for bladder tumor Muscle-invasive bladder cancer on postoperative histological evaluation Other malignant/benign tumors of the bladder (non-urothelial cancer)