Abstract P1-14-06: Selective internal radiation therapy (SIRT) with Yttrium-90 resin microspheres and FOLFOX/5FU chemotherapy in pre-treated breast cancer patients with liver metastases: A retrospective analysis of response rates, times to progression and survival of patients treated in Manchester UK between 2010 and 2016

Abstract

Abstract Background: SIRT is a globally licensed technique of Radio-Embolization (RE) of hepatic tumors via intra-arterial infusion of β-particle emitting Yttrium-90 (Y-90) radio-labelled microspheres. It increases response rates and hepatic time to progression in metastatic colorectal cancer when used in combination with 5FU/Oxaliplatin (FOLFOX) chemotherapy with acceptable toxicity profile. FOLFOX gives a radio-sensitizing effect and also controls disease outside the liver. Breast cancer liver metastases (BCLM) patients often have extra-hepatic disease and respond to multiple lines of systemic therapy and SIRT is infrequently used. Methods and patients Between 2010 and 2016 we treated 25 BCLM patients with Y-90 SIRT. Receptor status: 20 ER+ve/HER-2 -ve, 3 ER-ve/HER-2 +ve, 2 triple -ve. Eleven patients had liver only disease with 14 also having known extra-hepatic disease. Average number of previous lines of therapy in metastatic setting: chemotherapy = 2.4; endocrine = 1. Sixty-four % patients had prior Capecitabine (n=16); 12% platinum (n=3, all Carboplatin). Twenty patients received chemotherapy with SIRT: 17 had modified FOLFOX6 (Oxaliplatin/bolus 5FU day1, infusional 5FU day 1-3 (46 hrs); 3 patients had Modified de Gramont style 5FU alone. Five patients had no chemotherapy. Sir-spheres were inserted on day 2 of FOLFOX with the 5FU infusion pump continuing to day 3. Further 2-weekly FOLFOX chemo cycles were at clinician's discretion: average number delivered 3.8. Four patients had the liver treated in two halves, approximately 6 weeks apart. One patient received SIRT only to half the liver. Patients were imaged with PET-CT/CT before and 2-3 months after SIRT. Retrospective case note review was performed and data correlated to evaluate tumor response (RR); hepatic and extra hepatic progression free survival (HPFS and EHPFS) and overall survival (OS). Accurate toxicity data was not recorded. Results Hepatic CT response rates: PR 56% (n=14), SD 28% (n=7) and PD 16% (n=4). Hepatic PET response rates: CR 32% (n=8), PR 40% (n=10), SD 12% (n=3), PD 16%(n=4). (Overall PET liver disease control rate = 84%). Eight patients (32%) had extra-hepatic PD at first assessment. Of them, 4 had PR, 2 SD and 2 PD in the liver at that assessment. Two HER-2 +ve patients had brain metastases as first sign of PD within 75 days, an area not previously screened. Of 16 pre-treated with Capecitabine, liver CT response rates: 62.5% PR, 18.75% SD (n=10,3). Post SIRT/FOLFOX, average number of therapy lines: 2 for chemo and 0.75 for endocrine, with 8 patients still alive at time of censoring. Median OS: 766 HPFS: 210 days (CI 140-286). Median EHPFS in patients with extra-hepatic disease: 152 days (CI 96-636). Conclusions SIRT with FOLFOX in previously treated BCLM patients produces high response rates, excellent tumor control and time to progression in the liver with good overall survival. It does not seem to decrease the ability to give further lines of chemotherapy and can be considered as an option for breast cancer patients with liver metastases. Citation Format: Wilson G, Mullamitha S, Bentley D, Bell J, Mullan D, Carter L, Chittalia A, Howell S, Laasch H-U, Westwood T, Jeans S, Tipping J, Ryder D, Farquharson F, Arumugam P, Sheen A, Rajashanker B, Armstrong A, Misra V, Manoharan P, Lawrance J. Selective internal radiation therapy (SIRT) with Yttrium-90 resin microspheres and FOLFOX/5FU chemotherapy in pre-treated breast cancer patients with liver metastases: A retrospective analysis of response rates, times to progression and survival of patients treated in Manchester UK between 2010 and 2016 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-14-06.