Observation After Cytoreductive Nephrectomy in Patients With Synchronous Not Completely Resected Metastases of Renal Cell Carcinoma.

To determine the time-to-targeted therapy (TTT) in patients with not completely resected low-volume oligometastatic disease who were observed following debulking cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC).

Patients with synchronous mRCC with not completely resected low-volume metastases and in whom observation after CN was a multidisciplinary tumor board recommendation were identified from an approved institutional database. Patient data, International Metastatic Renal Cell Cancer Database Consortium (IMDC) risk, Fuhrman grade, site, and number of sites, time-to-progression (TTP), TTT, and overall survival (OS) were retrospectively analyzed.

From 251 synchronous mRCC patients treated since 2006, 40 (15.9 %) were identified who underwent CN with observation as a result of low-volume multiple metastasis considered not completely resectable (19 single site and 21 with ≥2 sites). IMDC risk was favorable in 7, intermediate in 24, and poor in 9 patients. Median TTP was 6 (range 2-30) months and TTT was 16 (range 2-43) months. In 11 patients targeted therapy was further deferred by observation beyond Response Evaluation Criteria in Solid Tumors progression and in 10 patients by additional local therapy of the most rapidly progressing lesion. Median OS was 30 (range 2-71) months.

In patients with synchronous mRCC and not completely resected low-volume metastasis, the TTT following CN was substantial. Local therapy to control the most rapidly progressing lesion or observation beyond progression was an additional means to defer systemic therapy.

Urology. 2017 Aug 02 [Epub]

Roderick E de Bruijn, Teele Kuusk, Allard P Noe, Christian U Blank, John B A G Haanen, Kees Hendricksen, Simon Horenblas, Axel Bex

Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands. Electronic address: ., Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands., Department of Medical Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.