Transurethral En Bloc Versus Standard Resection of Bladder Tumour

Bladder cancer is the 9th most commonly diagnosed cancer in men worldwide, with a standardized incidence rate of 9.0 per 100,000 person-years for men and 2.2 per 100,000 person-years for women. In Hong Kong, more than 400 new cases of bladder cancer are diagnosed every year. It is a common and important disease which carries a significant burden to the health medical system.

For patients who are diagnosed to have bladder tumours upon flexible cystoscopy, transurethral resection of bladder tumour (TURBT) should be offered. Being a minimally invasive procedure, it has become the standard for the initial management of bladder cancer. This operation aims to ascertain the diagnosis, to correctly stage the tumour (T-stage) and to cure the disease in the case of non-muscle-invasive bladder cancer (NMIBC). However, in a combined analysis of 2,596 patents from 7 randomised controlled trials in patients with NMIBC, it was shown that 1-year recurrence rate ranged from 15-61%, and 5-year recurrence rate ranged from 31-78%. Despite possible complete tumour resection during TURBT, the oncological control of NMIBC is far from satisfactory.

There are two main problems with the conventional standard resection (SR) procedure. First, the bladder tumour is resected in a piecemeal manner. This results in tumour fragmentation and floating tumour cells inside the bladder. The tumour cells may re-implant on to the bladder wall and lead to early disease recurrence. Second, 'complete tumour resection' is often determined by endoscopic vision only. Due to the inherited nature of piecemeal resection, it is not possible to assess the resection margin by histological means. The charring effect to the resection bed may also hinder the judgement of a 'complete tumour resection'. Routine second-look TURBT has been advocated for selected patients (Any presence of T1 disease, G3 disease, or any absence of detrusor muscle in the first TURBT specimen) even after a 'complete tumour resection' during the first TURBT. Second-look TURBT has been shown to detect residual disease in 33-55% of the patients and upstaging of disease in 4-45% of the patients. These results highlighted the limitations of TURBT in ascertaining complete tumour resection.

Transurethral en bloc resection (EBR) has been described as an alternate surgical technique in bladder tumour resection. By preventing tumour fragmentation and ascertaining complete tumour resection by histological assessment of the EBR specimen, we hypothesized that EBR could reduce disease recurrence as compared to SR.