Bladder urothelial cancer is the second most common urologic tumor and represents a worldwide public health problem. Most cases are diagnosed as non-muscle invasive tumors, and can be treated with transurethral resection of bladder tumor (TURBT). However, the electrical energy-based TURBT fragments the tumor, burning it to its own muscular layer leading to artifacts that may spoil the histopathological analysis, resulting in understaging after the first TURBT ranging from 30-64%, depending on the presence of detrusor muscle. Modern laser technologies have been emerging as an alternative to classical TURB using en bloc tumor resection technique (ERBT). Therefore, the laser is applied on tumor's pedicle to resect the whole and intact tumor without fragmentation or fulguration as occurs in TURBT. The purpose of using laser if to improve the resection quality, decrease intra and perioperative complications, avoid re-TURBT and reduce recurrence rates at the resection site and in distant sites. Thus, the purpose of this study is to evaluate Laser Holmium use for large tumors resection (>3cm), reducing complications, costs, and the need for new approaches, and improving the muscle layers samples.

This is a single-institution, randomized, single-blinded, prospective, controlled study, with 2 groups - 50 patients in Holmium Laser En-bloc Resection of Bladder Tumors (HoLERBT) arm and 50 patients in TURBT arm. All the patients will undergo a new procedure between 30-60 days after the first one (monopolar re-TURBT). The laser group will be operated by an experienced surgeon with more than 50 cases of prostate resection. The monopolar TURBT group will be operated by institutions´s surgeons assistants, urologists with more than 2 years of experience in the area and more than 50 surgeries performed. Pathological samples will be analyzed in the FMUSP Urology Laboratory by a pathologist with huge experience in analysis of bladder tumors.

Inclusion Criteria:

• Patients aged between 18 and 80 years old;
• Presence of bladder tumor > 3cm without signals of MIBC or advanced disease (US, CT scan or MRI 3 months before surgery)
• Able to understand and willing to sign a written informed consent document
• Satisfactory clinical pre operatory conditions for surgery with regional or general anesthesia.

Exclusion Criteria:

• Previous diagnosis of muscle-invasive bladder cancer;
• Tumor's Invasive aspect (T2 or more) on image (US, TC or RNM);
• Previous TURBT in the last 5 years;
• Urethral stenosis;
• Previous intra-vesical os systemic chemotherapy or radiotherapy;
• Previous treatment with intravesical BCG
• No clinical conditions for regional or general anesthesia;
• Any other significant disease or disorder which, in the opinion of the investigator may either put the participant at risk because of trial participation or may influence the trial result, or the participant's ability ti participate in the trial.