Impact of visceral metastasis on efficacy of fulvestrant in patients with hormone receptor-positive recurrent breast cancer

Background: Previous studies have suggested that the presence of visceral metastasis is a parameter useful in predicting the treatment efficacy of fulvestrant in patients with advanced breast cancer. Patients and Methods: We retrospectively examined the association between treatment efficacy and presence of visceral metastasis in 75 patients with hormone receptor-positive recurrent breast cancer who were treated with fulvestrant or no more than five lines of other endocrine monotherapy after recurrence. Results: Nineteen patients received fulvestrant, 10 of whom had visceral metastasis. The median time to progression was 4 months for the overall study population; it was significantly longer for patients with non-visceral metastasis (5.4 months; 95% confidence interval=3.7-11.2 months) than for those with visceral metastasis (3.3 months; 95% confidence interval, 0.4-5.3 months; p=0.01). No differences in time to progression were found between the groups of patients with visceral metastasis and non-visceral metastasis who underwent other endocrine therapies. Conclusion: Fulvestrant is more effective for patients with non-visceral metastasis of recurrent breast cancer with than for those with visceral metastasis.