ASCO 2017: Incidence of T3a upstaging and survival after partial nephrectomy: Size-stratified rates and implications for prognosis

Chicago, IL ( At the genitourinary cancer poster session at the 2017 ASCO annual meeting Dr. Srivastava and colleagues presented their population-level analysis of pT3a upstaging among patients undergoing partial nephrectomy. With increased experience and technology, the number of partial nephrectomies being performed for larger and more complex tumors is increasing. However, performing partial nephrectomy for larger tumors may increase the number of patients up-staged to pT3a who may have undergone a radical nephrectomy if pathologic stage were better delineated preoperatively. The objective of this study was to assess the number of patients upstaged to T3a disease after partial nephrectomy stratified by tumor size.

For this study the authors utilized the Surveillance Epidemiology and End Results (SEER) database from 1998-2013 to assess patients undergoing partial or radical nephrectomy. There were 28,854 patients that underwent partial nephrectomy and the proportion of upstaging to pT3a disease stratified by clinical stage was 4.2% for T1a, 9.5% for T1b, and 19.5% for T2. Among those receiving partial nephrectomy, survival analysis showed worse cancer specific survival (CSS) for patients up-staged pT3a patients versus pT1a (HR=1.87, p=0.02), pT1b (HR=1.91, p=0.01), and pT2 (HR=2.33, p=0.01) patients. When comparing partial nephrectomy and radical nephrectomy for pT3a disease, size-adjusted analysis revealed no difference in CSS or OS. Among pT3a patients undergoing partial nephrectomy, patients with larger tumors, measuring 4–7cm (OS: HR=1.44, p=0.04) or 7–16cm (OS: HR=2.64, p < 0.01), had worse survival than those with tumors < 4cm. The strength of the current study is the large sample size allowing long term survival analysis of pT3a patients stratified by clinical stage. A possible limitation for this study is that the SEER database lacks comorbidity data, which may affect OS outcomes

In conclusion, a greater proportion of patients experience T3a up-staging after partial nephrectomy with increasing clinical T-stage. Patients with pT3a disease after partial nephrectomy showed similar survival to pT3a patients after radical nephrectomy. However, pT3a patients undergoing partial nephrectomy had worse survival with increasing tumor size, reinforcing the need for improvements in identifying patients at risk of up-staging.

Presented By: Arnav Srivastava, Johns Hopkins University Medical Center, Baltimore, MD, USA

Co-Authors: Hiten Patel, Max Kates, Zeyad Schwen, Gregory Joice, Alice Semerjian, Phillip M. Pierorazio, Michael A. Gorin, Mohamad Allaf

Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre
Twitter: @zklaassen_md

at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 – Chicago, Illinois, USA