The TaHG bladder cancer – the devil is as black as he is painted

We have read with great interest the article entitled “Is there a role for second transurethral resection in pTa high-grade urothelial bladder cancer?”, published recently in the Central European Journal of Urology [1].

In their retrospective analysis of 112 patients with pTa high-grade (TaHG) tumours, the authors analysed the role of second TURBT (reTURBT). They have shown that after complete first TURBT, residual tumours were still found in 19.4% (7/36) of patients at the time of reTURBT. Despite this fact, reTURBT was found to have no statistically significant effect on recurrence free survival. While this finding is surprising, in our opinion it can be attributed to certain flaws of the study. Firstly, the population was small, (only 43/112 TaHG patients underwent reTURBT) and therefore the number of events was low. As only a minority of TaHG patients underwent reTURBT, this raises questions about the indications for the procedure in selected cases. Secondly, only a minor percentage of patients were given BCG maintenance, and some received only MMC. One of the advantages of reTURBT is its positive effect on BCG efficacy. However, as widely proved, in high-risk patients BCG maintenance is obligatory to substantially reduce the risk of recurrence and progression. Finally, the follow-up period was short.

The TaHG cancer is a rare entity among other NMIBCs. According to the current EAU clinical guidelines, TaHG tumours are not a subject for reTURBT. This recommendation was changed in 2017, because there was no clear clinical evidence supporting the role of reTURBT in such setting. Despite the fact that some reports prove profits from reTURBT in TaHG patients, it is believed that benefits may be lower than procedure morbidity and costs [2]. However, this statement may be true only in the situation of complete primary resection, high-quality histopathological assessment and fully compliant patients. This is not always the case in everyday practice. It should be remembered that besides the non-advanced stage, those poorly differentiated tumours (often associated with CIS concomitants) are loaded with a relatively low, but still significant risk of progression.

Recently, we have independently addressed similar questions in patients from Central Europe [3, 4]. In our studies, the residual tumour was found in 36–40% of cases at reTURBT, with the highest rate in TaHG cases (57%). Additionally, we have found statistically significant differences between cases with and without reTURBT in terms of recurrence-free and progression-free survival.

It has to be disclosed that all the studies mentioned above are burdened with limitations that impede the clinical relevance. Due to this, further prospective validation in bigger populations of patients with TaHG tumours is needed to fully understand the procedure which is controversial even in T1HG cancers [5].