Carcinoembryonic antigen (CEA) is an oncofoetal cell-surface glycoprotein that serves as an important tumor marker for different types of carcinoma. Combining of gold nanoparticle (Au-NP) and antibody-antigen specific molecular recognition was developed for CEA detection specifically as tumor biomarker in human urine. Our test was based on sandwich type immunoreaction principle on the lateral flow test strip as immunochromatographic strip tests (ISTs). We hypothesized that serum CEA level elevation in different cancer types patients reflected in high urine CEA levels also. Urine and serum CEA levels were determined by electrochemiluminescence (ECLIA) sandwich immunoassay test in 308 cancer patients (28 individual for each cancer type group; which subdivided into 4 tumor stages, each stage n=7). Studied Cancer types included: urinary bladder carcinoma, breast cancer, colorectal cancer, lung cancer, hepatome, prostate cancer, uterus cancer, spleen cancer, pancreatic cancer, gastrointestinal carcinoma, ovarian carcinoma and 100 normal control cases (50 male and 50 female). All urinary patients samples were applied by ISTs to detect ISTs ability in different cancer types early diagnosis. A significant difference was detected in serum and urine CEA levels respectively in all patients of the first and second stage compared to control cases, but a high significant difference was detected in serum and urine CEA levels respectively in all patients of the third and fourth stage compared to control cases. There was a definite relationship between serum CEA, urine CEA and patients malignancy stage; the higher stage, the higher serum and urine CEA levels and vice versa. ISTs showed red band test zone which its color intensity was proportionally to the patients malignancy stage, and agreed with patient urinary CEA level. In conclusion, urinary CEA is more useful in early different cancers types detection and its level is also correlated with tumor stage. ISTs thus provides a rapid, sensitive, low cost, individually usage clinical diagnosis tool for the detection of cancer by protein biomarkers (CEA) in human biological samples.
