Morphological and molecular characterization of the breast carcinoma

Objective: Morphological and molecularly characterize breast carcinomas diagnosed at the
Hospital Regional de Occidente, Quetzaltenango during the years 2020 to 2024. Materials
and methods: Quantitative, descriptive and cross-sectional study, with a total sample of 86
cases that met the inclusion and exclusion criteria. Results: The age range with the highest
frequency of cases was between 50 to 59 years with 30.2% of cases. Invasive carcinoma of
non-special type presented the highest frequency with 91.9% of cases. Histological grade III
presented the highest frequency with 69.6% of cases. ER presented a positive frequency in
64.0% of cases, PR presented a positive frequency in 53.5% of cases, HER2 presented a
positive frequency in 26.7% of cases and the Ki-67 antigen presented a high frequency of
positivity in 84.9% of cases. The luminal A subtype was found to be 13.4%, the luminal B
subtype (HER2-negative) was 40.2%, the luminal B subtype (HER2-positive) was 4.9%, the
HER2-overexpressed subtype was 23.2%, and the triple-negative subtype was 18.3%.
Conclusions: Breast carcinoma in Quetzaltenango presents some peculiarities with respect
to the national average. A higher frequency of aggressive tumors with histological grade III,
high Ki-67, and high frequency of more complex molecular subtypes was observed compared
to other studies conducted in Guatemala City.