Date of Award
2023
Document Type
Dissertation
Degree Name
Master of Medicine (MMed)
First Supervisor/Advisor
Dr Mustapha Abubakar
Second Supervisor/Advisor
Dr Jonathan Wawire
Department
AKU-East Africa
Abstract
Introduction: Breast cancer (BC) is the most common malignancy in women worldwide, including Kenya. Globally, increasing incidences of BC have paralleled those of obesity. The mechanism by which obesity contributes to BC is still an active area of research but white adipose tissue inflammation characterized by crown-like structures (CLS), which are macrophages surrounding dying adipocytes, is considered an important contributor.
Objectives: The primary objective was to determine the association between CLS and body mass index (BMI) in BC patients. The secondary objectives were to determine the association of CLS with BC risk factors specifically, age, menopausal status, subtypes of BC, and overall survival among BC patients.
Methodology: Surrounding non-tumor breast tissue from 180 BC surgical specimens was selected and stained immunohistochemically with CD68 to detect CLS. Demographic and clinical data was collected from medical records. Comparison between CLS presence and BMI categories with the other variables was determined based on the Fisher Exact test and Kruskal Wallis test. Multivariable logistic regression modeling was used to test the association between CLS presence and BMI categories. Models were adjusted for age, ER status, and menopause as potential confounders. A p-value of less than 0.05 was considered statistically significant.
Results: In multivariable models, obese patients were approximately two-fold more likely to have CLS in their tissues than normal-weight patients (Odds ratio (95% CI) = 2.03 (0.68-6.02)) but differences were not statistically significant (p = 0.204). BC risk factors specifically, age, menopausal status, subtypes of BC, and overall survival among BC patients were also not associated with CLS presence.
Conclusion: The findings were suggestive of higher CLS prevalence in surrounding non-tumor breast adipose tissue of obese than normal-weight women. Observed differences were, however, not statistically significant, which could be due to the low prevalence of CLS in this population, the relatively small sample size, or due to inherent tumor characteristics within this population.
Recommendations: Due to its low prevalence, CLS may not be the most ideal marker for white adipose tissue inflammation, and further studies looking into macrophage density and different types of macrophages within surrounding breast tissue are recommended.
Recommended Citation
Irungu, S. W. (2023). Relationship between crown like structures and body mass index in breast cancer (Unpublished master's dissertation). Aga Khan University, East Africa.