What is the best treatment option in postmenopausal, hormone responsive breast cancer patients with isolated bone metastases?

Bone is the most common metastatic site for breast cancer.

To determine the effectiveness of addition of chemotherapy to hormonal therapy in postmenopausal hormone receptor-positive breast cancer patients with isolated bone metastases.

Between June 2001 and January 2007, 101 patients were classified into two groups according to initial treatment modalities; patients who received hormonotherapy only (group I) and chemotherapy followed by hormonotherapy (group II). The effect of treatment choice on clinical course, time to progression, and overall survival were evaluated.

There were 70 patients in group I and 31 patients in group II. Bone metastases in 27 patients (26.7%) were synchronous and the remainder were metachronous. The median follow-up time was 41 months. The two groups showed similar results when patients' tumor characteristics were compared. However, 81% of synchronous cases had upfront chemotherapy following hormonotherapy, whereas this ratio was only 12% in the metachronous group. All patients received systemic antiresorptive bisphosphonates whereas only 24 patients required palliative radiotherapy at some time during the course of their disease. In groups I and II, the median time to progression was 12 and 16 months (P: 0.96) and median overall survival was 41 and 40 months (P: 0.79), respectively. In HER-2-positive patients, a trend of prolongation of overall survival was observed in group II, but it was not statistically significant (P: 0.12).

Anti-hormonal therapy still seems to be considered as the ideal treatment of choice for postmenapousal breast cancer patients with isolated bone metastases.