INCREASED SERUM LEVEL OF PEPTIDYL ARGININE DEIMINASE TYPE 4 IN VARIOUS MOLECULAR BIOLOGICAL SUBTYPES OF BREAST CANCER
Level of enzyme peptidyl arginine deiminase type 4 (PAD-4) was determined in serum samples collected from 98 females with primary breast cancer within January, 2017 - April, 2018 divided into 5 groups according to immunohistochemistry data: group 1 - luminal A cancer, 2 - luminal B Her-2 negative, 3 - luminal B Her-2 positive, 4 - non-luminal Her-2 positive, 5 - triple negative cancer. Samples were collected prior to the onset of any anti-cancer treatment, and in 41 cases - 15-24 days after performing radical surgery. Control samples were obtained from 20 healthy females. Serum PAD-4 level was measured with Human PAD-4 ELISA Kit (Wuhan Fine Biotech Co., Ltd, China) on automatic analyzer ADALTIS Personal LAB (Adaltis S.r.l., Italy). Statistical analysis was performed by using software IBM SPSS Statistics 19. Mean serum PAD-4 level before treatment was 9.0 ng/ml that did not change after surgery. However, mean PAD-4 level for healthy females was 1.5 ng/ml (0.0-2.0) ng/ml that significantly differed from cancer group (Mann-Whitney U test, U = 38.500, p<0.001). in contrast PAD-4 level in various cancer groups was: group 1 - 11.05 ng/ml, group 2 - 11.9 ng/ml, group 3 - 10.8 ng/ml, group 4 - 7.99 ng/ml, group 5 - 9.9 ng/ml. Thus, level of serum PAD-4 was higher in groups with more favorable luminal cancer, but further research is needed to make definitive conclusions.