Liver-directed therapy (LDT) for metastatic renal cell carcinoma (mRCC): Single center experience.

Abstract

681 Background: Liver metastases arising from RCC are common and signify a poor prognosis. Given the negative impact of liver metastases on overall survival (OS) and quality of life, it is reasonable to to consider therapies directly targeting these lesions in select patients. Little is known about how minimally invasive LDT affects outcomes in patients with mRCC. Methods: Nine patients with mRCC underwent LDT for liver-dominant or liver-only metastatic disease between 2005 and 2015. Retrospective chart review was performed under an IRB protocol to identify patient and disease characteristics, imaging response, and time to next systemic treatment, OS and toxicities. Patients were seen in clinic at one month post-LDT to monitor for toxicities. Imaging was obtained within 2 months prior to treatment and at 3 and 6 months following LDT. Results: Each patient underwent a median of 2.3 procedures. A total of 18 transarterial chemoembolizations (TACE) and 5 yttrium-90 radioembolizations were performed. 2 patients had metastatic disease confined to the liver, and 7 had liver-dominant disease. 7 had multifocal disease involving < 25% of the liver, and 2 had multifocal disease involving > 25% of the liver. 8/9 patients received prior systemic therapies, receiving a median of 3 (0-4) distinct treatments. 4/9 patients were undergoing systemic therapy at the time of LDT, 1 patient declined further treatment, and the median time to initiation of the next systemic therapy in the remaining patients was 3 months (range 2-4 months). Median OS from first line systemic therapy was 39 months, 95% CI [25.9-53.3], and the median OS from the first LDT was 22 months (from 5-45 months). Follow-up imaging post-LDT showed PR or SD in 88% of cases at 3 months and 44% of cases at 6 months. At one month post-procedure, 8/9 patients maintained performance status, and only one patient experienced CTCAE grade 3-4 toxicity. Conclusions: The median OS in RCC patients with liver disease and systemic therapy alone is 14.3 months. The improved median OS of 39 months with LDT in our unmatched and heavily pretreated cohort suggests a role for LDT. LDT is generally well tolerated and should be considered for patients with liver-dominant mRCC with good performance status.