Prognostic factors for survival in breast cancer patients who developed distant metastasis subsequent to definitive surgery.

INTRODUCTION: The present study was undertaken to define the prognostic factors for overall survival subsequent to definitive surgery, and for survival after the development of distant metastasis in breast cancer patients who developed distant metastasis subsequent to definitive surgery.
METHODS: The records of 470 breast cancer patients with T1-3 tumours and distant metastasis following surgery were reviewed. Prognostic factors were compared to the first metastatic sites as solitary skeletal, multiple skeletal, and visceral metastases, and were analysed for overall survival following surgery and survival after metastasis. Survival curves were generated by the Kaplan-Meier method, and multivariate analysis was performed by the Cox proportional hazard model.
RESULTS: 79 patients (17 percent) had a solitary skeletal metastasis, 105 (22 percent) had multiple skeletal metastases, and 286 (61 percent) had a visceral metastasis. The five-year overall survival was significantly better for patients with a solitary bone metastasis (73 percent) compared to patients who had multiple bone metastases (46 percent), or a visceral metastasis (22 percent) (p-value is less than 0.0001). Pathological lymph node status 3, stage IIIC, grade 3, oestrogen receptor negativity, and visceral metastases were found to have independent detrimental influence on overall survival following surgery and survival after metastasis. A long-term metastasis-free interval affected post-metastatic outcome favourably. Radiotherapy improved overall survival.
CONCLUSION: Pathological lymph node status, stage, grade, and oestrogen receptor status predicted survival after surgery as well as after the development of metastasis. Solitary bone metastasis has a more favourable prognosis than multiple bone metastases, and compared to visceral metastasis, skeletal metastasis has a more favourable prognosis.