Abstract: The search identified two studies (a multicenter study from Japan and the United Kingdom) with 361 participants. Primary outcomes Our results indicate that single-dose intravesical chemotherapy instillation may reduce the risk of bladder cancer recurrence over time compared to no instillation (hazard ratio [HR]: 0.51, 95% confidence interval [CI]: 0.32 to 0.82, low-certainty evidence). After 12 months follow-up, this would result in 127 fewer bladder cancer recurrences (95% CI: 182 to 44 fewer bladder cancer recurrences) per 1000 participants. We downgraded the certainty of evidence by two levels due to study limitations and imprecision. We found no trials that reported on the outcomes of time to death from upper tract urothelial carcinoma. The effect of single-dose intravesical chemotherapy instillation on serious adverse events is uncertain (risk ratio [RR]: not estimable, 95% CI: not estimable, there were no events, very low-certainty evidence). We downgraded the certainty of evidence by one level due to study limitations and by two levels due to imprecision. Secondary outcomes We found no trials that reported on the outcomes of time to death from any cause and participants’ disease-specific quality of life. The effect of single-dose intravesical chemotherapy instillation on minor adverse events is uncertain (risk ratio [RR]: not estimable, 95% CI: not estimable, there were no events, very low-certainty evidence). We downgraded the certainty of evidence by one level due to study limitations and by two levels due to imprecision. For patients who have undergone nephroureterectomy for upper tract urothelial carcinoma, single-dose intravesical chemotherapy instillation may reduce bladder cancer recurrence after nephroureterectomy. However, we are uncertain as to the risk of serious (and minor) adverse events. We found no evidence for the outcome of time to death from upper tract urothelial carcinoma. We were unable to conduct any of the preplanned subgroup analyses, particularly those based on operative approach, pathologic stage, and method of bladder cuff excision.

Plain-language summary: We found two randomised controlled studies (RCTs), with a total of 361 participants that compared a single-dose chemotherapy placed in the bladder to no chemotherapy in people having their kidney and ureter removed for cancer of the inner lining of the kidney or ureter, or both. These findings are based on a literature search up to April 15, 2019. We found that a one-time dose of chemotherapy put into the bladder after surgery may reduce the risk of this type of tumor coming back in the bladder over time compared to no chemotherapy. We found no evidence whether this affects the time to death from this type of cancer. Serious unwanted effects appear to be rare and not increased with chemotherapy, but we are uncertain of this finding. Our confidence in the evidence for the effect on the risk of recurrence within the bladder is low. This means that the true effect may be very different from what this review shows. The certainty of evidence for the effects of one-time chemotherapy put into the bladder on serious unwanted effects was very low. This means that we are very uncertain about this result.