Immunohistochemical Detection of Mutated P53 in Breast Cancer

Abstract

This is a retrospective descriptive study aimed to detect p53 mutation in breast cancer patients using immunohistochemical staining. The study was conducted in Radiation and Isotopes Center Khartoum (RICK) during the period from January to June 2013. Fifty paraffin embedded tissue blocks previously diagnosed as breast cancer were selected randomly, sectioned and stained immunohistochemically for detection of p53 mutation. The obtained data and results were analyzed using SPSS computer program. The patients information was collected from the archived files of patients. The patients ages ranged between 18-75 years with mean age of 55 years, the most of patients were older than 40 years representing 42 (84%) and the remaining 8 (16%) were younger than 40 years old. Out of 50 samples, histopathological diagnosis revealed invasive ductal carcinoma in 41 (82%) samples, mucinous carcinoma in 3 (6%) samples, invasive mammary carcinoma in 2 (4%) samples, papillary carcinoma in 2 (4%) samples, and only one sample (2%) with both tubulo lobular carcinoma and malignant stromal tumor. The majority of samples were demonstrated at late stage (grade 3) representing 25 samples (50%), grade 2 were 14 (24%) samples, grade 1 only one sample (2%), and the not graded were 10 (20%) samples. The study revealed that there is no association between the age and histopathological diagnosis (P.value>0.05). Positive expression of mutated p53 among study subjects represented 30 (60.0%) samples and the remaining 20 (40.0%) were negative with no statistical association between p53 mutation and histopathological diagnosis and grade (P.value>0.05). ER status showed positive expression in 24 (48.0%) samples and negative in 26 (52.0%) samples, PR showed positive expression in 18 (36.0%) samples and negative in 32 (64.0%) samples, and HER2 showed negative expression in 30 (60.0%) samples and positive expression in 20 (40.0%) samples. The relation showed insignificant statistical association between p53 mutation and ER, HER2 (P value > 0.05) and statistically significant association between p53 mutation and PR status (P.value <0.05). This study concluded that the positive expression of mutated p53 is more than negative expression with no relation with histopathological diagnosis, grade, ER, and HER2 expression, and statistically significant association between mutated p53 and PR status.