ASCO GU 2023: Radical Nephroureterectomy Followed by Adjuvant Chemotherapy Versus Observation in Early-Stage Upper Urinary Tract Cancers with Variant Histology

( The 2023 American Society of Clinical Oncology Genitourinary (ASCO GU) cancers symposium held in San Francisco, CA between February 16th and 18th was host to a prostate cancer and urothelial carcinoma poster session. Dr. Karan Jatwani presented his group’s study evaluating the role of adjuvant chemotherapy, versus observation, in patients with upper urinary tracts with variant histology undergoing a radical nephroureterectomy (RNU).

Upper tract urothelial carcinoma (UTUC) occurs less commonly and is associated with a worse stage-for-stage prognosis compared to urothelial carcinoma of the bladder, with variant histology being an independent predictor of worse outcomes. The POUT trial disproportionately included patients with urothelial predominant tumors.1 As such, the objective of this study was to evaluate outcomes of patients with UTUC variant histology who underwent adjuvant chemotherapy versus observation following an RNU.

The investigators queried the National Cancer Database (NCDB) for adult patients with UTUC variant histology diagnosed between 2004 and 2018. The cohort was restricted to patients who underwent an RNU and had pathologic node negative disease (i.e. pT2-4N0M0). Patients were divided into two groups based on the postoperative treatment strategy: RNU-AC and RNU-O. Patients who received neoadjuvant chemotherapy were excluded from analyses. Fisher’s exact and Mann Whiney U tests were used to compare frequency distributions. Multivariable Cox Proportional Hazards regression analysis was employed to evaluate predictors of overall survival. The multivariable model was adjusted for the following confounders: age, sex, race, income, educational level, clinical T stage, insurance status, and the Charlson Comorbidity Index.

A total of 522 patients were identified:

  • 133 (25.5%) received RNU-AC
  • 389 (74.5%) underwent RNU-O.

Patients in the RNU-AC group were younger (median 69 vs. 76 years, P <0.001). Patients with small cell (15.8% vs 4.9%), micropapillary (9.8% vs 5.9%) and adenocarcinoma (9% vs 6.7%) histologies were more likely to receive adjuvant chemotherapy, while those with squamous histology were less likely to receive AC (38.3% vs 50.6%) (p < 0.001 for all comparisons).

On univariable analysis, overall survival in the RNU-AC and RNU-O groups were non-significantly different (median of 27 versus 24.1 months, log rank-p= 0.63). On multivariable analysis, neither adjuvant chemotherapy use nor histological subtype was significantly associated with the hazard of overall survival (HR for AC = 0.96, 95% CI: 0.74 to 1.24, p = 0.75).

Presented by: Karan Jatwani, MD, Clinical Fellow, Medical Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY

Written by: Rashid Sayyid, MD, MSc – Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @rksayyid on Twitter during the 2023 Genitourinary (GU) American Society of Clinical Oncology (ASCO) Annual Meeting, San Francisco, Thurs, Feb 16 – Sat, Feb 18, 2023.