Relationship between proliferative activity of bone marrow micrometastasis and plasmatic level of a new cancer marker: lipid associated sialic acid (LASA) in human breast cancer.

The correlation between elevated level of a new plasma cancer marker, Lipid Associated Sialic Acid (LASA) and detection of bone marrow heterotopic epithelial cells by monoclonal antibodies using an immunocytologic technique, associated with the study of the proliferative activity of these heterotopic cells by measurement of their labelling index (LI) was analyzed in 158 samples obtained from 94 breast cancer patients. Six different groups of patients in complete remission of breast cancer, after radical treatment of the primary (minimal residual disease (MRD] were defined, according to the presence with or without proliferative activity of heterotopic cells in the bone marrow or the absence of such cells and to the level, normal or elevated of LASA in the serum of the same patient at the same time. 115 samples (73%) of the patients had an elevated LASA level at the time of the study among which 71 (45%) came from patients in which heterotopic cells were detected in the bone marrow, 32 (20%) of which with proliferative activity (LI+) 39 (25%) without (LI-). In 44 (28%) samples, no heterotopic cells were detected in the B.M. 43 samples (27%) of the patients had a normal LASA level. In 29 (18%) no heterotopic cells could be detected in the B.M. In only 14 could such cells be found, 5 with LI+, 9 with LI-. Both of these cytological and biological parameters can be useful markers of minimal residual disease and help to determine the prognosis and define optimal therapeutic strategy for curable breast cancer. Their prognostic value in predicting relapse awaits further observation with longer follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)