Breast cancer (BC) is a heterogeneous malignancy and it’s possible to identify by inmmunohistochemistry, four subtypes with different clinical and biological behavior. Our aim was to evaluate the prevalence, disease free survival (DFS) and overall survival (OS) influence of these subtypes on the Guatemalam population.
Data of 954 patients Instituto Guatemalteco de Seguridad Social treated from 2008-2014. BC subtypes were categorized in Luminal A (RE+ and/or RP+, HER2-), Luminal B (RE+ and/or RP+, HER2+ o Ki-67> 14%); HER2 (RE-, RP-, HER2+) and triple negative tumors (TNT) (RE-, RP-, HER2-).
Median age was 52 years (23-95), 55% were premenopausal. We found that 522 (56%) of the cases were luminal A, 190 (20%) were triple negative tumors (TNT), luminal B were 73 (8%) and HER2-positive in 152 (20%) of cases. Nine patients (3%) had other breast cancer contralateral. In 438 (70%) of all the cases were found in locally advanced stages (IIB–IIIC); 773 (81%) patients underwent radical mastectomy and 181 (19%) undergoing conservative surgery. We have found in the univariate analysis the following statistically significant variables for DFS: clinical stage (I – IIa vs IIb – IIIC; 88% vs 70%; p = 0.001), nuclear grade (grade 1, 2 vs 3; 83% vs 62%; p = 0.001) and pathologic response to neoadjuvant chemotherapy (total vs other response; 76% vs 54%; p = 0.001), and status Her-2 subtype was borderline (positive vs negative; p = 0.079). Clinical stage (p = 0.05), histologic grade (P = 0.45), response to neoadjuvant (p = 0.01) as significant factors of prognosis for the OS. The OS by molecular subtype were Luminal A (94%), Luminal B (75%), HER2 (79%) and TNT (68%), (p = 0.001).
The prevalence of molecular subtypes of BC is similar to reported internationally. In Guatemala the majority of patients with BC are diagnosed in advanced stage.
Hugo Castro.
Has not received any funding.
All authors have declared no conflicts of interest.