Shima Habibi - Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
Hassan Jamshidian - Department of Urology, Medical School, Tehran University of Medical Sciences, Tehran, Iran.
Mahdi Kadivar - Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran.
Mohammad Reza Eshraghian - Department of Epidemiology & Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Mohammad Hassan Javanbakht - Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
Hoda Derakhshanian - Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
Mahmoud Djalali - Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran

Background: The gold standard for detection of bladder cancer is cystoscopy, which is an invasive and complicated procedure. Our study was conducted to find a tumor marker with high specificity, sensitivity, and accuracy for the diagnosis of bladder cancer. Methods: Serum samples were collected from ۵۸ bladder cancer patients and ۶۰ healthy control subjects. Levels of lipid-bound sialic acid (LBSA), and protein-bound sialic acid (PBSA) were measured spectrophotometrically by Aminoff’s method. Results: Mean levels of both markers were found to be significantly higher in the patients than the healthy controls. Positive correlations were observed between serum levels of lipid- (r=۰.۲۸۳, p<۰.۰۵) and protein- bound (r=۰.۵۶, p<۰.۰۵) sialic acids and the grade of malignancy. To differentiate patients with bladder tumors from healthy controls, cut-offpoints were determined for each of the two parameters based on Receiver Operating Characteristic (ROC) curve analysis (LBSA=۲۱.۲۵ mg/dL, PBSA=۶.۱۵ mg/dL). The data showed good sensitivities (LBSA=۸۹%, PBSA=۷۹%), specificities (LBSA=۷۰%, PBSA=۷۰%) and accuracies (LBSA=۸۳%, PBSA=۸۱%) for both markers. Conclusion: Measuring serum LBSA and PBSA by this simple, reproducible, noninvasive, and inexpensive method can accurately discriminate cancer patients from healthy individuals.

N-Acetylneuraminic Acid, Tumor Markers, Urinary Bladder Neoplasms