LUMINAL B IS THE MOST COMMON BREAST CANCER SUBTYPE IN PATIENTS OF ALMATY ONCOLOGY CENTER

Abstract

Introduction: Breast cancer is a heterogenous group of disease that is most prevalent malignant disease of female
population of Kazakhstan.
Aim of study: to find most common pathologic type and molecular subtype of breast cancer cases in the Almaty
oncology center and evaluate association among molecular subtype with different pathological type, tumor characteristics
and Participant’s criteria
Materials and methods: A cross sectional study was conducted at Almaty oncology center, Kazakhstan between
January and December 2020. We studied medical records of 818 breast cancer cases and included data of 622 cases in this
study. Data about pathologic type, grade, stage, estrogen (ER), progesterone (PR) HER2 overexpression and ki67 were
analyzed. Molecular subtype determination in this center was done by using immunohistochemistry and this Criteria
(‘Luminal A-like’ ER/PR +, HER2-, Ki67 low) (‘Luminal B-like' ER/PR +, HER2 ± and Ki67 high) (‘HER2-positive’ HER2+ ER
and PR -) (Triple-negative ER and PR absent HER2-). The association were evaluated among molecular subtype with
different pathological type, tumor characteristics and Participant’s criteria using Chi square test
Results: Most common pathologic type of tumor in this study was NST (85.3%), ILC (3.8%) and DCIS (2.1%)
respectively. Most prevalent molecular subtype of tumors: Luminal B (57.6%), luminal A (22.2%), triple negative (12%) and
HER/2 enriched (8.3%). There was statistically significant association (p-value <0.05) between Molecular subtype and
pathologic type of tumor, grade, stage, size, hormone receptors, HER/2 over expression and mitotic rate.
Conclusion: luminal B was the most prevalent subtype and HER2 positive was the least prevalent and it is better to
work more for finding better treatment for luminal B. A significant association among molecular subtype of tumor and
pathologic subtype, grade, stage, size, hormone receptors, HER/2 over expression and mitotic rate were found.