[Diagnostic value of total and lipid-bound sialic acid in malignancies]

Malignancies are the second cause of death among people after cardiovascular diseases. The early detection of tumors could increase the possibility of a favorable treatment outcome. Many biochemical tumor markers have become known during the last forty years, but each of them has some clinical limitations. Recently, the main attention of researchers is focused on tumor-derived compounds as possible markers of neoplasia. In this paper, the diagnostic value of serum total sialic acid (TSA) and lipid-bound sialic acid (LSA) has been summarized in malignant disease including the diagnosis, staging, prognosis and follow up of cancers. The clinical studies showed that TSA and LSA concentrations in serum were significantly elevated in different types of cancers compared to values of healthy people and with nonmalignant diseases. In the initial phase of malignant diseases, TSA and LSA as single tests for detection of cancers are not useful according to low diagnostic sensitivity. TSA and LSA concentrations in serum allow with some probability to assay the staging of cancer. LSA is more sensitive and specific test than TSA. Besides, serum TSA and LSA levels good reflect effectiveness of therapy. The decrease of concentration indicates on tumor regression (effective therapy) and the increase means the progression of disease (failing therapy). TSA and LSA can be useful biochemical indicators for staging, prognosis, monitoring of effectiveness treatment of cancers and early detection of recurrence or metastases, especially in combination with other tumor markers.