Breast Cancer Characteristics and Immunohistochemical Profiles in Women Aged 41–69 Years.

Abstract

Background:

Breast cancer remains a major global public health challenge, with a disproportionately high mortality burden in sub-Saharan Africa due to late-stage diagnosis and limited access to screening and treatment services. Understanding the biological heterogeneity of breast cancer in this region is essential to improve early detection and personalized management strategies. To describe the sociodemographic, clinical, radiological, and pathological characteristics of women aged 41–69 years with breast cancer and to identify factors associated with immunohistochemical marker expression (ER, PR, HER2/Neu, and Ki67).

Methodology:

A retrospective analytical multicenter study was conducted among 185 women with histologically confirmed breast cancer across five referral centers in Kinshasa and Matadi, Democratic Republic of the Congo, from January 2015 to December 2023. Data on sociodemographic, clinical, imaging, and pathological variables were collected. Associations with immunohistochemical markers were assessed using univariate and multivariate logistic regression analyses, and results were expressed as adjusted odds ratios (aOR) with 95% confidence intervals (CI).

Results:

The mean age was 51.9 ± 7.9 years, with a predominance of women aged 41–55 years (67%). Most tumors were invasive (90.3%) and predominantly invasive ductal carcinoma (64.9%). High Ki67 expression was observed in 70.3% of cases. Menopause, elevated BMI, advanced clinical stage, alcohol consumption, BI-RADS 5 lesions, and calcifications were significantly associated with aggressive immunohistochemical profiles. Multivariate analysis identified menopause and advanced stage as independent predictors of ER-negative expression, while BMI and alcohol consumption were strongly associated with HER2/Neu positivity.

Conclusion:

Breast cancer in this population is characterized by early onset and biologically aggressive tumor profiles. Clinical, radiological, and metabolic factors significantly influence immunohistochemical expression, underscoring the need for integrated screening strategies and individualized management approaches in resource-limited settings.