Efficacy and prognostic factors for y-90 radioembolization (Y-90) in metastatic neuroendocrine tumors with liver metastases.

Abstract

Background. Yttrium-90 (Y-90) can be an effective liver-directed therapy for patients with metastatic neuroendocrine tumors (NETs), but population-based data are limited. We characterized the use of Y-90 in NET patients and identified factors associated with response. Methods. We identified 49 patients with metastatic liver-dominant NETs across BC Cancer's six regional centres who received Y-90 between June 2011 and January 2017 in British Columbia, Canada. Baseline characteristics, radiographic responses, and outcomes were summarized. Results. Of the 49 patients who received Y-90, the median age was 56 years (range 21-78), 49% were male, and 94% had an ECOG performance status of 0-1. e primary location of the NET included pancreas (31%), small bowel (41%), large bowel (6%), unknown (14%), and others (12%). 69% of these patients had liver metastases alone, and tumors were graded as G1 (61%), G2 (25%), G3 (2%), and unknown (12%). Prior therapies included surgery (63%), local ablative therapy (25%), somatostatin analogue (69%), and systemic therapy (35%). e median Y-90 dose was 2.2 GBq (range 0.8-3.6), as SIR-spheres (69%) or eraSpheres (29%). Median time to Y-90 from diagnosis of metastases measured 1.54 years. 88% received segmental Y-90, with 1 (69%), 2 (29%), and 3 (2%) treatments. Y-90 resulted in partial response (53%), stable disease (33%), and progressive disease (12%). Y-90 was well-tolerated, with infrequent grade 3-4 biochemical toxicities (2%) and grade 3 abdominal pain (6%). Longer overall survival (OS) was associated with resection of primary tumor, well-differentiated histology, and low Ki-67. Median OS was 27.2 months (95% CI 8.0-46.5).Conclusions. In our population-based cohort, Y-90 was welltolerated in patients with metastatic liver-dominant NETs. Prior surgical resection was an important predictor of OS.

Radioembolization for Metastatic Neuroendocrine Tumors

“…Factors that are commonly found to be predictive of better OS after TARE are female gender, well-differentiated tumor, low K i -67, good performance status, low hepatic tumor burden, and absence of extrahepatic metastases. 48,[53][54][55] A recent two-institution retrospective analysis showed no difference on long-term PFS or OS between TACE and TARE, despite TACE showing a greater DCR. 64 Toxicity Short-term toxicities following TARE have been described as minor, and in 2015 a multidisciplinary group of experts convened to form the NET-Liver-Metastases Conference that reviewed 11 reports on TAE or TACE and 7 on TARE.…”

“…13 Most cohort studies included data on NETLMs within a mixed population of non-NET tumor types, and the ones that focused on NETLMs comprised mostly a small number of patients, heterogeneous tumor types, with lack of details on primary tumor site and/or grading. 49,51 Most data from cohort studies on TARE and NETLMs come from 90 Y resin rather than glass microspheres, 48,49,[51][52][53][54][55][56] with no standardized follow-up, and inconsistency in reporting both objective response rates (ORRs) and survival. 49 Therefore, the systematic review and meta-analyses that resulted from these publications were also limited, as they included multi-institutional studies which resulted in inclusion of overlapping patients.…”

“…However, interestingly there was a trend toward worsened prognosis with TARE versus TACE, 54 which was seen in a previous study comparing these two treatment modalities. 63 Tsang el al 55 reported on 49 patients treated mostly with 90 Y resin TARE (SIR-Spheres 69%, TheraSphere 29%, 2% unknown; between June 2011 and January 2017 across six regional centers in British Columbia, Canada). The median OS of this group was 27.2 months (95% CI: 8.0-46.5), which is comparable to previously reported outcomes that measured from 22 to 70 months.…”