Association between Molecular Subtype of Invasive Breast Carcinoma with grade, lymphovascular invasion and lymph node metastasis in the Department of Anatomic Pathology FKUI/RSCM 2019

Abstract

Background
Breast cancer is classified into molecular subtypes: luminal A, luminal B, HER2 enriched and triple negative breast cancer based on
its immunohistochemical profile. This study aims to assess the relationship between histologic grade, lymphovascular invasion and
lymph node metastasis with molecular subtypes in invasive breast carcinoma at Cipto Mangunkusumo Hospital from January 1,
2019 to December 31, 2019.
Methods
A descriptive, cross-sectional study was conducted in Anatomical Pathology Department, FKUI/RSCM over a period of January to
December 2019. A total of 652 histologic specimens with a diagnosis of invasive breast carcinoma which were immunostained with
ER, PR, HER2, and Ki67 were reviewed, then grouped into the appropriate molecular subtypes. A Chi-square test was performed to
assess the association between histologic grade, lymphovascular invasion and regional lymph node metastases with molecular
subtypes.The p-value <0.05 was statistically significant.
Results
The molecular subtypes of breast cancer, from the highest to the least number, were luminal A (40.2%), luminal B (37.7%), TNBC
(13.6%), and HER2 enriched (8.6%). There was a significant association between grade and molecular subtypes of breast cancer.
(p=<0.001). There was a significant association between lymph node metastasis and molecular subtypes of breast cancer
(p=0.038).
Conclusion
The most common molecular subtype of invasive breast cancer found was Luminal A. There was a significant association between
lymph node grade and metastasis and the molecular subtype of breast cancer.