PCA-Index: The combination of serum levels of p53 and CA125 for breast cancer early detection

Abstract Introduction Early-stage diagnosis is crucial for the best prognosis in breast cancer. Here, our objective was to compare serum tumor protein p53 (TP53) levels in an Egyptian population with benign breast disease vs breast cancer to investigate the protein’s utility in early detection and intervention, alongside existing tumor-related markers, including carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), and CA15.3. Methods We enrolled 231 patients in this study: 146 with breast cancer, 50 with benign conditions, and 35 without breast pathology (healthy control individuals). The serum level of TP53, CEA, CA125, and CA15.3 was quantitated using an enzyme-linked immunosorbent assay. Data were examined using the t test, Spearman correlation, and receiver operating characteristic curve analysis. Results Patients with breast cancer showed clinically significant higher serum levels of TP53 than did individuals with benign conditions and healthy control individuals. Elevated TP53 levels were correlated with advanced tumor stage (P <.001) and high-tumor grade (P <.001). TP53 effectively distinguished between benign disease and early-stage breast cancer, with an area under the curve of 0.88, 73.6% sensitivity, and 78.0% specificity. Multinomial logistic regression analysis showed that combining TP53 with other tumor-related markers improved early breast cancer detection. Both TP53 and CA125 remained significant predictors in this analysis. A new function, the PCA-Index, which combines concentrations of TP53 and CA125, was developed to enhance early detection in early stages (T1-T2) and low grades (1-2) with notable results: areas under the curve of 0.96 and 0.98, a specificity of 90.0%, and sensitivities of 85.7% and 91.7%, respectively. Discussion The combined detection of TP53 and CA125, the PCA-Index, has important clinical value for early detection of breast cancer with a high degree of sensitivity and specificity.