Association of Reproductive Factors with Breast Cancer Biological Characteristics in Older Women in the Democratic Republic of the Congo

Gertrude Luyeye Mvila; Tacite Kpanya Mazoba; Guy Kusakana Walisiya; Antoine Molua Aundu

doi:10.31557/RRO.2026.12.1.69

Authors

Gertrude Luyeye Mvila Department of Medical Imaging and Radiology, University of Kinshasa, Kinshasa, DR Congo. Interdisciplinary Center for Research in Medical Imaging (CIRIMED), University of Kinshasa, Kinshasa, DR Congo. Centre d’imagerie du Congo (CEIMEC), University of Kinshasa, Kinshasa, DR Congo. Centre Pilote d’imagerie Médicale Kokolo (CEPIM).
Tacite Kpanya Mazoba Department of Medical Imaging and Radiology, University of Kinshasa, Kinshasa, DR Congo. Interdisciplinary Center for Research in Medical Imaging (CIRIMED), University of Kinshasa, Kinshasa, DR Congo.
Guy Kusakana Walisiya Department of Medical Imaging and Radiology, University of Kinshasa, Kinshasa, DR Congo.
Antoine Molua Aundu Department of Medical Imaging and Radiology, University of Kinshasa, Kinshasa, DR Congo. Interdisciplinary Center for Research in Medical Imaging (CIRIMED), University of Kinshasa, Kinshasa, DR Congo.

DOI:

https://doi.org/10.31557/RRO.2026.12.1.69

Abstract

Introduction: Reproductive factors, including age at menarche, age at menopause, and parity, are established determinants of breast cancer risk. However, their relationships with tumor biological characteristics remain insufficiently characterized in older women, particularly in sub-Saharan Africa. This study investigated the associations of age at menarche, age at menopause, and parity with breast cancer characteristics and the Ki-67 proliferation index among women aged ≥60 years in the Democratic Republic of the Congo (DRC).

Methods: A prospective, multicenter analytical study was conducted from 2015 to 2023 at four medical centers in Kinshasa, DRC. Women aged ≥60 years with histologically confirmed breast cancer who underwent mammographic, ultrasonographic, histopathological, and immunohistochemical evaluation and had available reproductive history were included. Patients with nonmalignant breast diseases and male patients were excluded. Clinical, imaging, histopathological, and immunohistochemical data were collected and analyzed using IBM SPSS Statistics version 21.0. Associations between categorical variables were assessed using the Pearson chi-square test. Correlations between reproductive factors and Ki-67 expression were also evaluated.

Results: The study included 91 women with a mean age of 68.6 ± 5.4 years. The mean ages at menarche and menopause were 13.4 ± 1.6 and 50.5 ± 4.6 years, respectively. Most lesions were classified as BI-RADS 4 (58/91, 63.7%), followed by BI-RADS 5 (19/91, 20.9%) and BI-RADS 3 (15/91, 16.5%). Age at menopause was higher among women with BI-RADS 4 and BI-RADS 5 lesions than among those with BI-RADS 3 lesions. Age at menarche differed significantly across tumor biological subgroups, including estrogen receptor-positive tumors (13.1 ± 1.3 years; p = 0.047), HER2-overexpressing tumors (13.8 ± 1.3 years; p = 0.044), triple-negative tumors (12.9 ± 2.1 years; p = 0.004), and triple-positive tumors (13.6 ± 0.9 years; p = 0.002). Significant differences in age at menarche were also observed according to histological type (p = 0.039) and histological grade (p = 0.023). Age at menopause showed a moderate inverse correlation with Ki-67 expression, whereas age at menarche showed a strong linear correlation that did not reach statistical significance.

Conclusion: Among older women with breast cancer in the DRC, age at menarche was associated with several histopathological and tumor biological characteristics, while age at menopause showed an inverse relationship with Ki-67 expression. These findings suggest that reproductive timing may be associated with tumor biology in older women. Larger, well-designed prospective studies with comprehensive and standardized assessment of reproductive history are needed to validate these findings.