Klin Onkol 2001; 14(6): 197-202.

Summary: Background: The question of the ionising irradiation influence on steroid hormone receptor quantification in a subsequent Brest carcinoma surgery remains clinically unaswered. Materials and Methods:The saturation analysis technique with activated charcoal and 3H labelled ligands was used to assay cytosol estradiol receptors (cER), cytosol progesterone receptors (cPgR) and nuclear estradiol receptors (nER) in two sets of primary breast carcinoma specimens (pT 1-3, pN 0-2, MO) collected during surgeries between 1980 and 1990. One group (Group A, N=90) consisted of specimens from tumours preoperatively fractionally irradiated with a total of 20 Gy, the specimens of the other group (Group B, N=52) were not subject to radiation therapy prior to surgery. Results: Markedly lower ER values in pre-irradiated tumours were found in the nuclear fraction only, while the ER level decrease in the cytosol fraction was not statistically significant. The statistically significantly lower cPgR median in pre-irradiated specimens was very probably partly due to the grade of differentiation. Compared with Group B, Group A had a significantly smaller number of tumours in which both cytoplasrnic receptors of steroid hormones clinically tested as positive (cER+/cPgR+), significantly smaller numer of nER-/cPgR+ tumours, but a substantially higher numer of tumours with the nER-/cPgR- combination. Conclusions: Our results confirmthe differences in the expression of steroid hormones in malignant breast tumours with and without pre-irradiation. The results seem to support the assumption that preoperative irradiation of breast tumours may impair the function of estrogen and progesterone signalling pathways in the tumour tissue. The authors believe that a thorough understanding of the consequences irradiation may produce in both healthy and oncologically affected tissue of the mammary gland remains a clinically topical issue even today