Degree of manifestation of therapeutic pathomorphosis and the nature of the change in the estrogen and progesterone receptors after the radiation and chemotherapy of breast cancer

Estradiol and progesterone receptor levels were measured in 130 patients with stage III breast tumors before treatment and following preoperative radiation or chemotherapy. The data were evaluated versus the morphologic features of posttreatment pathomorphosis of tumor. Standard fractionated radiation (total dose of 70 Gy) was followed by pronounced postradiation pathomorphosis and a decrease in the level and incidence of steroid receptors in 72.7-87.5%. The essentially unchanged receptor profile of tumor following large-fraction (total dose-20 Gy) irradiation as well as presence of estradiol and progesterone receptors in the originally receptor-negative neoplasms after chemotherapy were matched by a slight degree of pathomorphosis.