Cytokeratins and proliferation in breast cancer patients

Abstract

Tissue polypeptide antigen (TPA) was studied in 242 sera and 165 tumor cell cytosols (both evaluations in 67 cases) of breast cancer patients, for which proliferative activity, determined by the TLI technique, was also available. The TPA serum and tumor cell cytosol median values (utilized for measure analysis as cut-off) were 70 U/1 and 377 U/mg cytosol protein, respectively. High serum TPA levels were associated with unfavourable clinicopathological characteristics whereas a higher tumor cell cytosol TPA level was associated with better cytohistological tumor differentiation. Furthermore, no overall correlation was found between serum and tumor cell cytosol TPA levels or between their levels and TLI. When analyzing cases in which serum and tumor cell cytosol TPA values were higher than 100 U/l and 500 U/mg cytosol protein, respectively (n = 28), serum TPA was positively associated with TLI (slope = 12.3 r = 0.55, p < 0.01), while cytosolic TPA resulted negatively associated with TLI (slope = -87.4 r = 0.41, p < 0.01). Finally, a strong inverse relationship between cytosolic and serum TPA (p < 0.0005) became evident. We suggest that TPA could represent a serum marker for tumor cell proliferation in specific patient subgroups with original high serum and/or cytosol TPA expression.