Clinico-pathologic factors associated with the occurrence of early and late metastatic spread in a cohort of breast cancer patients.

BACKGROUND AND OBJECTIVE Distant metastatic spread in breast cancer patients is a complex phenomenon involving several prognostic factors. We focused our analysis on early metastatic breast cancer (EMBC) (occurring during the first 36 months) versus late metastatic breast cancer (LMBC) (occurring beyond 3 years) in order to ascertain their possible differential predictive factors. METHODS diagnostic, surgical, and follow-up data were assessed for consecutive patients with breast cancer undergoing surgery between 1997 and 2019. We analysed the predictive factors for distant metastasis using both univariate and multivariate analysis. RESULTS The median follow-up for this cohort of 2708 patients was 89 months. The median metastasis-free interval (FMI) for metastasis patients was 38 months (17 months for EMBC group and 76 months for LMBC group). Distant metastases developed in 12.9% (350/2708); 48% (168/350) of them as EMBC and 52% (182/350) as LMBC. Loco-regional recurrence and nodal extracapsular extension were the only common predictors for both. CONCLUSIONS EMBC and LMBC appeared as two separate conditions, with a different outcome. In the EMBC group, tumour proliferation related factors were significant (histological grade, tumour size, body mass index), whereas for LMBC, other slow-acting factors seemed to be involved (screening program, tumour burden, bilateral tumour).