To investigate the clinical characteristics and prognosis of luminal B subtype breast cancer patients with bone metastases.

The data of one hundred and twenty-eight cases of luminal B subtype breast cancer with bone metastases were collected from January 2004 to January 2012, 75 of whom were HER-2 negative and 53 were HER-2 positive. The clinical characteristics and prognosis were analyzed retrospectively.

There were statistically significant differences in the confirmed age of bone metastases, the size of the primary tumor, the number of axillary lymph node metastases, and the time of postoperative bone metastasis between the two groups (χ²=4.477, 6.927, 12.209, 11.222, P=0.034, 0.023, 0.002, 0.004). The median survival time and 5-year survival rate of luminal B HER-2 negative type breast cancer patients after bone metastases were 29.8 months and 22.7%, and 27.1 months and 20.7% respectively for luminal B HER-2 positive type breast cancer patients. There was no significant difference in survival time after bone metastasis between the two groups (χ²=0.398, P=0.528).

Luminal B HER-2 positive type is more common than luminal B HER-2 negative breast cancer patients with bone metastasis in older age, larger diameter of primary tumor, more axillary lymph node metastasis, and earlier bone metastasis after surgery. There is no significant difference in the prognosis of two type patients.