Metastatic breast cancer patients with lung or liver metastases should be distinguished before being treated with fulvestrant.

Background: Endocrine therapy is the preferred treatment for patients with hormone receptor -positive metastatic breast cancer (MBC). While visceral metastasis is a negative prognostic factor, few studies have distinguished between the prognoses of patients with metastases at different visceral sites.

Patients And Methods: In total, 398 patients receiving fulvestrant 500 mg at a single center over a 6-year period were analyzed. Logistic regression models were used to identify the prognostic factors associated with progression-free survival (PFS). Kaplan-Meier analysis was used to compare the PFS of patients with lung and liver metastases.

Results: Baseline visceral metastases were present in 233 patients, including 138 with lung metastases (lung metastases without liver involvement), 51 with liver metastases (liver metastases without lung involvement) and 41 with lung and liver metastases. The median PFS was 6.8 months (5.6 and 9.2 months for visceral and nonvisceral metastases, respectively, P = .028). PFS was longer in patients with lung metastases than in those with liver metastases or lung and liver metastases (9.6, 3.7 and 3.2 months, respectively, P < .001; liver vs. lung hazard ratio (HR) 1.70; lung and liver vs. lung HR 2.85). Patients with liver metastases experienced significantly worse PFS than those without liver involvement (3.7 vs. 9.2 months, P < .001). PFS benefits were observed in patients with longer disease-free intervals, no liver metastases, and no previous chemotherapy.

Conclusion: Fulvestrant treatment benefited patients with lung or nonvisceral metastases. When treating hormone receptor-positive/HER2-negative MBC patients with endocrine therapy, it is important to differentiate patients with lung metastases from those with liver metastases.