EAU 2018: Risk-based Surveillance After Surgical Treatment of Renal Cell Carcinoma

Copenhagen, Denmark (UroToday.com) Post-operative surveillance for renal cell carcinoma is to some degree risk stratified, primarily on pathologic staging. Current EAU guidelines utilize the University of California Los Angeles Integrated Staging System (UISS) to help risk stratify patients. In this abstract, the authors externally validate that staging system using their own institutional data encompassing 1,630 patients treated with either partial (PN) or radical nephrectomy (RN), and then followed with a standard post-surgery surveillance protocol regardless of recurrence risk. Specifically, they assessed the staging system’s ability to predict early (≤12 months) and late (>60 months) recurrence after surgery, and then compared it to a new model that includes patient age and disease histology (not currently included).

Of the cohort of 1630 patients, 854 patients (52%) were treated with RN and 776 (48%) were treated with PN. As expected, the most common histology was clear cell [1273(78%)]; in contrast, papillary type 1, papillary type 2, and chromophobe tumors were found in 137 (8.4%), 113 (6.9%), and 107 (6.6%) patients, respectively. Most were ECOG 0-1 (85%), Fuhrman grade 1-2 (72%), node-negative (96%), and pT1-2 (78%). In terms of recurrence, 221 (15.4%) patients recurred within the first year after surgery.

Both investigated models (UISS and modified UISS+age+histology) showed high accuracy in predicting early recurrence after surgery, with an AUC of 0.84 (95% CI: 0.81, 0.88) for the new model and 0.83 (95% CI: 0.80, 0.87) for the UISS model. Both models showed a good net benefit in predicting early recurrence at decision curve analysis.

Of note, patients diagnosed with low-risk tumor types (e.g., papillary type 1 and chromophobe), the average risk of early recurrence significantly dropped within each UISS risk category when tumor histology was added to the predictive model (1.6% vs. 0.6% in the low-risk category; 5.5% vs. 1.9% for intermediate-risk; 45% vs. 22% for high-risk).

In contrast, Kaplan-Meier analyses showed no difference in the risk of late recurrence among UISS risk categories.

As such, the authors note that the UISS model should be applied, as recommended by the EAU Guidelines, to tailor the follow-up protocol in the early period after surgical treatment of RCC (within the first 12 months). Patients with low-risk histology, specifically papillary type 1 and chromophobe, deserve a less stringent follow-up, regardless of their UISS risk category.

As for late recurrence, their results do not support the use of a risk-stratification model to design a surveillance protocol after five years post-surgery, as the recurrence risk is the same across risk categories.

Speaker: P. Capogrosso

Co-Author(s): Muttin F., Larcher A, Sjoberg D., Vertosick E., Cianflone F., Dell'Oglio P., Carenzi C., Salonia A., Vickers A., Montorsi F., Bertini R., Capitanio U.

Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, Twitter: @tchandra_uromd at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark