Homocysteine in breast cyst fluid.

Background: Elevated plasma homocysteine concentrations have been reported in a variety of carcinoma, including those of the breast. The risk of breast cancer is higher in patients suffering from gross cystic disease. The breast cyst fluid contains unusual amounts of low- and high- molecular substances, including steroid hormones and their conjugates. The present study was undertaken to find out the presence of homocysteine in the fluid filling the cysts and have its concentration compared with other thiols, levels of Na+/K+ ratio and steroid hormones. Materials and methods Fourteen women suffering from gross cystic disease were enrolled in this study. Cystic concentrations of homocysteine (Hcy), cysteine (Cys), cysteinylglycine (Cys-Gly) and glutathione (GSH) were determined by high performance liquid chromatography, with fluorescence detection; estradiol (E2), progesterone, allopregnanolone and pregnenolone sulfate (PregS) by RIA methods.

Results: Mean levels of Hcy, Cys, Cys-Gly, Na+/K+, E2 and PregS in the fluid filling the breast cysts were significantly higher than the corresponding plasma concentrations. In addition, a negative correlation was found between cystic Hcy and the Na+/K+ ratio (Rs = -0.72, P = 0.003) and positive correlations between cyst Hcy and estradiol (Rs = 0.64, P = 0.018) and Hcy and PregS (Rs = 0.60, P = 0.025). Conclusion The study provides the first evidence of thiol concentrations in the breast cyst fluid. The finding of a negative correlation between homocysteine and the Na+/K+ ratio support the idea that the homocysteine concentration in breast cysts might be used clinically as a marker for the development of breast cancer disease.