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).