Adjuvant chemotherapy after radical nephroureterectomy for upper tract urothelial carcinoma with variant histology: A systematic review and meta-analysis of survival outcomes.

INTRODUCTION:To determine effects of adjuvant chemotherapy (AC) on survival outcomes compared to surgery alone without AC for upper tract urothelial carcinoma (UTUC) patients with variant histology (VH). METHODS:We conducted a systematic review and meta-analysis of studies investigating AC for UTUC in Medline, Embase, the Cochrane library up to January 2023. Population, intervention, comparator, and outcome were UTUC patients with VH, radical nephroureterectomy with AC, radical nephroureterectomy only, and oncological survival, respectively. RESULTS:Four retrospective studies were included. Regarding overall survival (OS), the pooled hazard ratio was 0.61 (95% confidence interval: 0.42-0.87; p = 0.007) across two studies. Regarding cancer specific survival (CSS), the pooled hazard ratio was 0.46 (95% confidence interval: 0.25-0.84; p = 0.01) across three studies. All included studies had a high quality based on the Newcastle-Ottawa Scale. Certainty of evidence for OS was low. Certainty of evidence for CSS was moderate due to a strong association (hazard ratio < 0.5). Publication bias was not significant for any studies. CONCLUSION:In UTUC patients with VH, administration of AC after surgery might have better survival outcomes than surgery alone. Our study provides evidence for decision-making of clinicians who treat UTUC patients with VH.