Introduction:

triple-negative breast cancer has a more aggressive biological behaviour and is associated with an unfavourable prognosis.

Objective:

to determine the incidence of triple- negative breast cancer molecular subtypes and its relationship with other clinical and pathological variables of prognostic value.

Methods:

a descriptive and retrospective study was carried out at "Celestino Hernández Robau" University Teaching Hospital from Villa Clara between January 2017 and June 2019 in order to determine the incidence of triple- negative tumors and its relationship with the variables: age, tumor size, histological type and grade as well as proliferative index.

Results:

the incidence of triple- negative breast cancer molecular subtype and its relationship with moderate and poorly differentiated histological forms were determined.

Conclusions:

triple- negative breast cancer molecular subtype is frequently associated with postmenopausal age, ductal histological type, high histological grade, high Ki-67 indices and tumor size greater than 2 cm.