Systemic failure after intial treatment of breast cancer is the most troublesome issue. To investigate the factors influencing on the outcome of metastatic breast cancer, this study was designed.

Two hundred sixty-seven breast cancer patients with distant metastasis after initial treatment were included for this study. The patients showing confined metastasis to the ipsilateral supraclavicular lymph node, were excluded. Preferred sites of metastasis, intervals to distant metastasis, survival rates after systemic failure were investigated in association with clinico-pathological parameters. Student ttest, chi-square test and log-rank test were used for statistical analysis.

Patient age ranges from 20 to 71 years of age (mean 44.9). Forty-eight patients (18%) were initially included in stage 0 or I, 137 (51%) in stage II, and 82 (31%) in stage III. The preferred sites of metastasis were bone (47%), lung (29%), liver (9%), brain (8%) and multiple organs (4%) in descending order. Initial pathologic stage (P<0.001) and lymph node metastasis (P=0.016) were associated with the interval to distant metastasis, but not the tumor size (P=0.246). Poor survival after systemic failure was associated with metastasis to the multiple organs or to liver (P<0.001), with no treatment after failure (P<0.001), and with failure within 3 years after initial treatment (P=0.056).

Bone is the most prevalent metastatic site of breast cancer. Axillary lymph node status, especially the number of involved nodes, was associated with shorter disease free survival after initial treatment, which suggests that it might be a predictor of micrometastasis and a marker for an aggressive systemic treatment. Hepatic metastasis and metastasis to multiple organs was a poor prognostic marker of metastatic breast cancer. An aggressive systemic treatment after systemic failure might improve the survival.