Molecular sub types of breast cancer in a developing country. Classification immunohistochemical: Clinicopathologic feature and survival analysis

Date 03 May 2019
Event ESMO Breast Cancer 2019
Session Poster lunch
Topics Cancer Care Delivery in Low Resource Environments
Breast Cancer
Pathology/Molecular Biology
Presenter Hugo Castro
Citation Annals of Oncology (2019) 30 (suppl_3): iii27-iii33. 10.1093/annonc/mdz096
Authors H.R. Castro1, L. Salazar2, L. Garcia2, N. Castro Sanchez1, P. Ramos1, K. Cruz1
  • 1Medical Oncology, Instituto Guatemalteco de Seguridad Social (IGSS), 1015 - Guatemala/GT
  • 2Medicina Legal, Instituto Guatemalteco de Seguridad Social, 01015 - Guatemala/GT

Abstract

Background

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.

Methods

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-).

Results

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).

Conclusions

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.

Editorial acknowledgement

Clinical trial identification

Legal entity responsible for the study

Hugo Castro.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.