Abstract
<jats:p>Previously it has been shown that steroid hormones, estradiol and progesterone (E2 и Pg); antibodies of A and G class against benzo[a]pyrene (IgA1-Bp and IgG1-Bp), estradiol (IgA1-E2 and IgG1-E2), progesterone (IgA1-Pg and IgG1-Pg) and corresponding antiidiotypic antibodies (IgG2-E2 and IgG2-Pg) may influence breast carcinogenesis. It was proposed that some of these effects way be enhanced or inhibited upon combined action of these factors in breast cancer (BC) patients. Hence, only some of these hormones and autoantibodies may show significant associations with tumor growth. Our study aimed for searching effects of E2 и Pg, IgA1-Bp and IgG1-Bp, IgA1-E2 and IgG1-E2, IgA1-Pg and IgG1-Pg, IgG2-E2 and IgG2-Pg in regulation of tumor proliferation in BC patients. Blood serum autoantibodies in 1258 BC cases (620 with I stage and 638 with II-IV stages) were studied using ELISA technique. Concentrations of steroid hormones were measured using “ImmunoEA-Estradiol”, and “ImmunoEA-Pg” (JSC “Immunotech”, Russia). Tumor Ki-67 was determined by standard immunohistochemical technique. Statistical analysis of the results was performed using CART algorithm of Statistica13.0 Software. The contents of Ki-67 positive cells in tumors of stage I BC were increased when blood serum Pg concentrations were high and depended on levels of IgA1-Bp, IgG1-Bp, IgA1-E2 and IgG2-E2. The levels of Ki-67 positive cells in tumors of II-IV stages BCP were high when IgG2- Pg were low and IgA1-Bp were increased. The levels of these factors were similar in blood serum of stage I and stage II-IV patients. Hence, the revealed difference in associations of tumor proliferation with studied serum factors could be dependent on changes of tumor cells receptivity during cancer progression. Immunoanalysis of IgG2-Pg and IgA1-Bp may be used for determination of tumor proliferation in BCP. It is proposed to study antiproliferative properties of artificially produced antibodies against Pg receptor for replenishment of IgG2-Pg deficiency in BCP.</jats:p>