Immunohistochemical p21 expression in Breast Cancer: Association with patient and tumour characteristics
Date of Award
Master of Medicine (MMed)
Prof. Ronald Wasike
Prof. Hassan Saidi
Dr. Shahin Sayed
General Surgery (East Africa)
Introduction: Molecular characterisation of the breast cancer has allowed for targeted therapies that are improving outcomes. The gains achieved by these treatments have fuelled the search for other targets, including cyclin-dependent kinase inhibitors such as p21. p21 expression in breast cancer has been shown to be variably associated with clinical and pathological parameters in different populations. It is possible that either methodological or biological differences underlie these variations.
Objective: The current study sought to determine the association of p21 expression and clinico-pathological parameters in breast cancer patients at the Aga Khan University Hospital in Nairobi, Kenya.
Methods: Clinically annotated tissue samples were obtained in a consecutive fashion. Specimen were immunohistochemically stained for p21 expression with clinicopathological data extracted for corresponding cases. p21 expression was assessed against age, parity, menopausal status, body mass index, hormonal receptor status, tumour size and grade. Distribution of mean p21 score was assessed for normality and data were analysed using Kruskall-Wallis test, chi-square and Fisher's exact test at an alpha level of 0.05. They were presented in form of tables, charts and photomicrographs.
Results: Ninety-eight cases were included in the study. Mean age was 47.55 years with mean parity 2.96 live births. A slight majority of patients were pre-menopausal (56.3% versus 42.5%). Average body-mass index was 29.69 kilograms per square metre. Majority of patients had invasive ductal carcinoma (87.6%) that was moderate-to-high grade (92.7%), 2 centimetres or larger (95%), with lymphovascular invasion (70.4%), and vi hormone-receptor positive. Mean expression of p21 at 1:100 dilution was approximately 20% was statistically significant with tumour size.
Conclusion: The findings of the current study demonstrate a possible association of p21 expression with tumour size. The demonstration of a trend towards p21 loss with increasing body mass index may benefit from exploration with a larger dataset.
Njihia, B. N. (2017). Immunohistochemical p21 expression in Breast Cancer: Association with patient and tumour characteristics (Unpublished master's dissertation). Aga Khan University, East Africa.