Abstract

Objective: Gross cystic breast disease (GCBD) is the most common benign breast disease. There are two types of breast cyst; lined by apocrine epithelium (Na/K<3) or flattened epithelium (Na/K>3). Several studies have shown that women with palpable breast cysts may have 1.7-7.5 times higher risk of developing breast cancer. Patients with malignant disease usually show abnormal amino acid profiles in the peripheral circulation. Changes in amino acid profile diagnostically correlate with organ sites of malignancy. The aim of this study was to investigate the levels of amino acids in two cyst groups and possible mechanisms involved in the development of breast cancer.

Material and Methods: The breast cyst fluid aspirated from women with GCBD were analysed. Breast cyst fluid amino acid levels were determined with HPLC.

Results: Aspartic acid, glutamic acid, hydroxyproline, serine, glycine, threonine, alanine, proline, tyrosine, methionine, isoleucine, leucine, phenylalanine and tryptophan levels were significantly higher, and lysine levels were lower in the apocrine epithelial cysts.

Conclusion: In this study, higher concentrations of amino acids in apocrine cysts, which are also known to have a higher risk of developing breast cancer, may indicate the possible role(s) of amino acids in the mechanism of breast cancer development.