Comprehensive immuno-hormonal assessment of the risk of breast cancer in postmenopauseal women

The study aimed to determine the personal combinations of blood serum estradiol and progesterone (E2 and Pg), classes A and G antibodies against E2, Pg and Benzo[a]pyrene (IgA1-E2, IgA1-Pg, IgA1-Bp; IgG1-E2, IgG1-Pg, IgG1-Bp), class G antiidiotypic antibodies to E2 and Pg (IgG2-E2, IgG2-Pg) levels associated with breast cancer in postmenopausal women. Material and Methods. There were investigated 763 nonsmoking women: 206 healthy and 557 breast cancer patients (BCP) with I stage BC before treatment. The blood serum levels of hormones and antibodies were studied using competitive and non-competitive enzyme immunoassay, respectively. Statistical analysis of the results was performed using Statistica 13.0 Software, Classification and Regression Trees (CART-analysis). Results. There were revealed 7 groups according to personal combinations of IgG2-E2, E2, IgA1-E2, Pg, and IgG1-Bp associated with BC risk. High E2 levels in combination with high IgG1-Bp levels were revealed in 54.2 % of BCP vs 26.7 % of healthy women (p<0.001; OR=3.3 [2.3–4.7]). Low Pg levels in combination with low IgG1-Bp levels and average IgG2-E2 levels were more often found in BCP than in healthy women (9.9 % vs 3.9 %; p=0.01; OR=2.7 [1.3–5.8]. The various combinations of high and low levels of studied factors in others 5 groups were found in 72.4 % of healthy women and in 36.4 % of BCP. Concentrations of E2 and Pg were not correlated with studied antibodies and anti-antibodies levels. Levels of antiidiotypic antibodies were not associated with corresponding idiotypic antibodies. Conclusion. The effect of E2 and Pg on breast cancer development was demonstrated only in combination with IgG2-E2, IgA1-E2, and IgG1-Bp. Immunoassay of antibodies and antiantibodies to E2, Pg and Bp is recommended for research of chemical induced hormone-depended human carcinogenesis.