Sequential intra-arterial infusion of 90Y-resin microspheres and mitomycin C in chemo refractory liver metastatic breast cancer patients: a single centre pilot study.

Background The aim of the study was to evaluate the safety and feasibility of intra-arterial mitomycin C (MMC) infusion after selective internal radiation therapy (SIRT) using Yttrium-90 (90Y) resin microspheres in liver metastatic breast cancer (LMBC) patients. Patients and methods The prospective pilot study included LMBC patients from 2012-2018. Patients first received infusion of 90Y resin microspheres, after 6-8 weeks response to treatment was assessed by MRI, 18F-FDG PET/CT and laboratory tests. After exclusion of progressive disease, MMC infusion was administrated 8 weeks later in different dose cohorts; A: 6 mg in 1 cycle, B: 12 mg in 2 cycles, C: 24 mg in 2 cycles and D: maximum of 72 mg in 6 cycles. In cohort D the response was evaluated after every 2 cycles and continued after exclusion of progressive disease. Adverse events (AE) were reported according to CTCAE version 5.0. Results Sixteen patients received 90Y treatment. Four patients were excluded for MMC infusion, because of extra hepatic disease progression (n = 3) and clinical and biochemical instability (n = 1). That resulted in the following number of patient per cohort; A: 2, B: 1, C: 3 and D: 6. In 4 of the 12 patients (all cohort D) the maximum dose of MMC was adjusted due biochemical toxicities (n = 2) and progressive disease (n = 2). One grade 3 AE occurred after 90Y treatment consisting of a gastrointestinal ulcer whereby prolonged hospitalization was needed. Conclusions Sequential treatment of intra-arterial infusion of MMC after 90Y SIRT was feasible in 75% of the patients when MMC was administrated in different escalating dose cohorts. However, caution is needed to prevent reflux after 90Y SIRT in LMBC patients.

Intra-arterial Mitomycin C infusion in a large cohort of advanced liver metastatic breast cancer patients: safety, efficacy and factors influencing survival.

PURPOSE: The aim of this study was to determine the safety and efficacy of Mitomycin C (MMC) infusion in a large cohort of advanced liver metastatic breast cancer patients (LMBC) and to determine factors influencing overall survival (OS). METHODS: We retrospectively analysed LMBC patients, treated with MMC infusion between 2000 and 2017. Hepatic response was measured with baseline CT scans and first available CT scan after MMC infusion by RECIST 1.1 criteria. Adverse events were registered by the CTCAE version 5.0. OS and hepatic progression free survival (hPFS) were evaluated using Kaplan-Meier estimates. After univariable analysis, a stepwise forward multivariable (MV) prediction analysis was developed to select independent pre-treatment factors associated with OS. RESULTS: We included 176 patients with a total of 599 MMC infusions, mostly heavily pre-treated patients with a median time from diagnosis of MBC to MMC infusion of 36.9 months. RECIST evaluation of liver lesions (n = 132) showed a partial response rate of 15%, stable disease of 43% and progressive disease in 17%. Adverse events grade 3 and 4 were reported in 17.5%. Median PFS was 5.5 months and median OS was 7.8 months. Significant independent baseline predictors of worse OS included number of prior systemic chemotherapy lines, prior liver ablation, higher liver tumour burden and elevated levels of bilirubin and ALT. CONCLUSION: MMC infusion is safe and effective in advanced LMBC patients. An increased number of prior therapies, a higher liver tumour burden and elevated levels of bilirubin and ALT were associated with a worse OS.