In patients with unresectable hepatic metastases from metastatic melanoma and neuroendocrine tumors, radioembolization led to good outcomes in studies from Emory University School of Medicine reported at the 38th Society of Interventional Radiology Annual Scientific Meeting, held recently in New Orleans.
Metastatic Melanoma Study
“Systemic chemotherapy for metastatic melanoma to the liver is largely ineffective, and median survival after diagnosis generally ranges from 2 to 7 months,” according to Hasmukh J. Prajapati, MD, a Senior Associate in Radiology at Emory. The extent of metastases generally renders surgery or ablation ineffective, but a survival advantage has been reported after yttrium-90 radioembolization therapy in this patient population, he said.
The study included 24 consecutive patients who received a total of 42 yttrium-90 procedures over a 9-year period at Emory.1 Bilobar disease was present in 92%; index lesion size was 3–7 cm in 42% and > 7 cm in 42%; 29% had > 8 liver lesions, 8% had portal vein thrombosis, and 75% had additional extrahepatic metastases. The primary tumor was ocular in 60%, cutaneous in 40%.
The median survival from the time of first yttrium-90 procedure was 13.4 months (range, 1 month to 7 years). Median survival from initial melanoma diagnosis was 121.4 months, and from a diagnosis of liver metastases was 19.9 months.
Tumor response was significantly associated with progression-free survival, which was 19.6 months for the 12.5% of patients with a partial response, 10.3 months for the 62.5% with stable disease, but only 1.3 months for the 25% of nonresponders, Dr. Prajapati reported. For patients who received one cycle of treatment (92%), median survival was 12.9 months, while those with repeat cycles (8%) had a median survival of 21.3 months (P = .06).
The investigators evaluated factors that were significantly related to improved survival after yttrium-90 radioembolization, and found survival to be highest in patients with Child Pugh class A (15.1 months), < 8 liver lesions (17.7 months), and an absence of extrahepatic metastases (21.4 months).
Neuroendocrine Tumors
Emily B. McIntosh, a medical student at Emory, reported the results of a retrospective analysis that compared patients with neuroendocrine tumors and hepatic metastases treated with (n = 46) and without (n = 113) yttrium-90 radioembolization.2 The 159 patients were identified from the Emory Cancer Registry and were treated between 2003 and 2012.
A few baseline differences were noted between the two groups. Patients treated with yttrium-90 had a longer time to the development of hepatic metastases, were more likely to have at least 10 hepatic lesions, had lower bilirubin levels, and were more likely to have received octreotide acetate (Sandostatin) as a previous treatment.
“The median overall survival after treatment with yttrium-90 was 1.3 years,” Ms. McIntosh reported. Interestingly, patients treated with yttrium-90 had a greater number of liver lesions than patients not receiving this treatment. They also had a longer interval between the primary diagnosis and hepatic metastasis as well as lower bilirubin levels.
From the time of the initial diagnosis, median survival time was essentially doubled among patients treated with yttrium-90: 4.2 years compared with 2.0 years in the untreated group (P = .005). From the time of diagnosis of hepatic metastases, median survival was significantly improved: 2.8 years compared with 1.7 years, respectively (P = .02).
“Independent prognostic factors for survival from hepatic metastases were treatment with yttrium-90, treatment with [octreotide], tumor burden, and bilirubin,” she said.
The Cox proportional hazards model, controlled for time from primary diagnosis to hepatic metastases, identified the following hazard ratios: number of hepatic lesions > 10 (2.51), treatment with yttrium-90 (0.53), treatment with octreotide (0.43), elevated bilirubin (1.17), and size of largest hepatic lesions (1.07).
She added that while octreotide was independently associated with a survival benefit, previous studies have not shown this. ■
Disclosure: Dr. Prajapati and Ms. McIntosh reported no potential conflicts of interest.
References
1. Prajapati HJ, Dawson DH, Kim HS: Selective internal yttrium-90 radioembolization therapy in patients with unresectable metastatic melanoma to liver, refractory to systemic therapy: Analysis of imaging findings, survival and factors associated with prolonged survival. Society of Interventional Radiology Annual Scientific Meeting. Abstract 64. Presented April 15, 2013.
2. McIntosh EB, El-Rayes B, Kauh J, et al: Resin-based yttrium-90 radioembolization for metastatic neuroendocrine tumors in a single-center cancer registry. Society of Interventional Radiology Annual Scientific Meeting. Abstract 65. Presented April 15, 2013.
