Abstract:
Objective: This study was conducted to determine the immunohistochemical expression of cyclin D1 in invasive breast
carcinoma and its association with already established prognostic parameters like estrogen receptor (ER), progesterone
receptor (PR), HER2/Neu, and Ki67 status.
Study Design & Setting: Cross sectional Observational. Department of Pathology, Armed Forces Institute of Pathology,
Rawalpindi
Methodology: The study included 350 cases of invasive breast cancer diagnosed between January 2023 and December
2023. Data collected included patient age, histological subtype, molecular subtypes, tumor size, and the presence of estrogen
(ER) and progesterone (PR) receptors, as well as HER2/Neu and Ki67 status. Patients who had undergone chemotherapy,
received radiation to the breasts, or experienced relapse were excluded from the study. Immunohistochemistry was conducted
using a Cyclin D1 antibody to assess Cyclin D1 expression in tissue samples. The expression levels were categorized as
negative, weak, moderate, strong staining in tumor cells. Data analysis was performed using SPSS 29.0, and statistical
comparisons were made between Cyclin D1 staining and ER, PR, HER2/Neu, and Ki67 status.
Results: Cyclin D1 moderate to strong staining was seen in 173/352 (49.14%) cases of invasive BC. Cyclin D1 expression
was slightly statistically significantly associated with ER (x2 = 7.78, P value <0.051) and Ki67 positivity (÷2 = 7.27, P
value <0.064).
Conclusion: Cyclin D1 has the potential to serve as a prognostic marker. Incorporating it into the routine IHC workup for
breast cancer could enhance patient management, especially with the development of new targeted therapies that inhibit
the Cyclin D-CDK4/6 axis.
