Safety, efficacy, and prognostic factors after radioembolization of hepatic metastases from breast cancer: A large single-center experience in 81 patients

The present study evaluated safety, efficacy, and prognostic factors for ⁹⁰Y-yttrium microsphere radioembolization of unresectable liver metastases from breast cancer. Methods: Eighty-one patients were treated with radioembolization. Acute toxicity was monitored through daily physical examination and serum tests until 3 d after radioembolization; late toxicity was evaluated until 12 wk after radioembolization. Overall survival and response according to ¹⁸F-FDG PET (>30% decrease of tracer uptake) and CA15-3 serum level (any decline) were recorded. Pretherapeutic characteristics, including pretreatment history, liver function tests, and PET/CT parameters, were assessed by univariate and subsequent multivariate Cox regression for predicting patient survival. Results: A toxicity grade of 3 or more based on clinical symptoms, bilirubin, ulcer, pancreatitis, ascites, or radioembolization-induced liver disease occurred in 10% or less of patients. Two patients eventually died from radioembolization-induced liver disease. Sequential lobar treatment and absence of prior angiosuppressive therapy were both associated with a lower rate of serious adverse events. On the basis of PET/CA15-3 criteria, 52/61% of patients responded to treatment. Median overall survival after radioembolization was 35 wk (interquartile range, 41 wk). Pretherapeutic tumor burden of the liver greater than 50% or more (P < 0.001; hazard ratio, 5.67; 95% confidence interval, 2.41-13.34) and a transaminase toxicity grade of 2 or more (P = 0.009; hazard ratio, 2.15; 95% confidence interval, 1.21-3.80) independently predicted short survival. Conclusion: Radioembolization for breast cancer liver metastases shows encouraging local response rates with low incidence of serious adverse events, especially in those patients with sequential lobar treatment or without prior angiosuppressive therapy. High hepatic tumor burden and liver transaminase levels at baseline indicate poor outcome.