Predictors of early distant metastasis in women with breast cancer

Breast cancer is a clinically heterogeneous disease. Approximately 10-15 % of breast cancer patients develop distant metastases within 2 years of diagnosis with a poor 5-year survival rate of 21 %. Little data have been gathered about how some breast cancer metastasizes earlier than expected. The study aimed to identify predictors of distant metastases among breast cancer patients in relation to their clinical and tumour characteristics. The results of the study may have important implications in our understanding of the disease process allowing more aggressive treatment and monitoring of certain subgroups of patients.

Retrospective review of 215 patients (54 % early stage and 46 % locally advanced stage) who fulfilled the specified criteria was performed. Twelve variables were considered. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of developing distant metastasis within 24 months after surgery and adjuvant therapy.

Of the 215 patients, 27.9 and 17.7 % developed bone and visceral metastasis, respectively. Bone metastasis was significantly dependent on stage, tumour size, lymph node involvement, lymphovascular invasion, estrogen receptor, progesterone receptor and Her/2-neu pattern (p < 0.05). Visceral metastasis was significantly dependent on age, menopausal status, stage, tumour size, lymph node involvement, estrogen receptor, progesterone receptor and Her-2/neu pattern (p < 0.05). Among patients with bone and visceral metastases, 67 and 43 % have triple negative pattern, respectively. Logistic regression provided an accurate model for predicting bone but not visceral metastasis.

A significant fraction of breast cancer patients experienced early metastasis. Our data suggest that tumour stage, size and lymph node involvement are major predictors of metastasis. Her-2/neu over-expression alone is not a strong predictor of early metastasis but triple negative breast cancers belong to an aggressive subgroup with early metastatic capacity. Young, premenopausal patients may benefit from aggressive surveillance and treatment since they tend to present with early visceral spread.