SUO 2017: Differences Between De Novo vs Secondary Upper Tract Urothelial Carcinoma

Washington, DC ( Upper tract urothelial carcinoma (UTUC) accounts for <5% of all urothelial cancers (UC). While traditionally considered a part of the spectrum of UC, it was often considered to be a secondary malignancy of bladder cancer (BC). However, as sporadic UTUC independent of BC was increasingly identified, while still rare, there was more interest in understanding the difference between de novo UTUC (dnUTUC) and UTUC secondary to BC (SUTUC). 

The authors of this study utilized their institutional experience to compare these entities to better delineate differences between the cohorts. They identified all patients treated for UTUC between 2002-2016. Retrospective chart review of these patients resulted in clinical, pathological and follow-up parameters. Patients were stratified according to whether their disease was DnUTUC or SUTUC, determined by prior BC history. 

They identified a total of 128 UTUC patients, of which 98 had DnUTUC (76.5%) and 30 with SUTUC (23.5%), which in itself is surprising. Mean age and gender differences were similar (mean age: 70.5 vs 69.1, p=0.548; % male: 83.3% vs 70.4%, p=0.161 for DnUTUC vs. SUTUC, respectively). However, DnUTUC patients had a lower age adjusted Charlson score (6.4 vs 7.5, p=0.039). In both groups 70% of patients had high grade (HG) disease, more than 43% had Ta disease and more than 37% had T2 and above disease. Interestingly, the presence of CIS and recurrence rates were much higher in SUTUC than in DnUTUC (56.7% vs. 25.5%, p=0.001, and 70.4% vs. 39.8%, p=0.005, respectively). 

Treatment strategy was similar with more than 80% undergoing nephroureterectomy in both groups. Cancer specific mortality (CSM) was better in DnUTUC with only 11.5% (vs. 32.1% for SUTUC) dying of their disease, p=0.058. Multivariable logistic regression analysis demonstrated that male gender and SUTUC disease significantly predicted higher recurrence rates.

Based on this single center experience spanning more than a decade, patients with DnUTUC appear to be more common than SUTUC, and most have high-grade disease. Compared to patients with a history of BC, there is a much lower CIS incidence and recurrence rates. This may be due to the selection of BC who progressed to UTUC having worse disease than those who never progressed to UTUC. 

These findings raise the question whether follow-up strategies for recurrence should differ between DnUTUC and SUTUC – specifically, with lower rates of recurrence, perhaps lower tract surveillance in dnUTUC may not be as essential?

These results are intriguing and warrant further follow-up.

Limitations / Discussion Points:

1. There is no comparison to BC patients who don’t develop UTUC – they may be more comparable to dnUTUC patients in terms of outcomes.

2. UTUC is notoriously difficult to accurately stage pre-operatively. While the authors use pathologic staging, it would be interesting to note differences in clinical staging.

Presented by: Hanan Goldberg, MD

Co-Authors: Douglas Cheung, Zachary Klaassen, Thenappan Chandrasekar, Rashid Sayyid, Girish Kulkarni, Robert Hamilton, Andrew Evans, Bharati Bapat, Theodorus van der Kwast, Neil Fleshner

Institution: Princess Margaret Cancer Center, UHN, Toronto, Ontario, Canada

Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, twitter: @tchandra_uromd at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC