Expression of estrogen receptors alpha and beta in two uterine mesenchymal tumors after prolonged tamoxifen therapy. Report of two cases.
BACKGROUND
Tamoxifen therapy is associated with an increased risk of endometrial carcinoma, and possibly uterine sarcomas. Little is known about hormone receptor expression in mesenchymal tumors of the uterus after tamoxifen therapy.


METHODS
The cases of two patients with uterine mesenchymal tumors after prolonged tamoxifen therapy due to breast cancer are presented. The expression of estrogen receptors alpha (ERalpha) and beta (ERbeta) and progesterone receptors (PR) was studied immunohistochemically in both cases. Both tumors were negative for ERalpha and positive for ERbeta. In the first case the tumor was negative for PR, while in the second only 20% of nuclei were PR-positive.


CONCLUSIONS
Consistent with previous studies, uterine mesenchymal tumors after tamoxifen therapy do not express ERalpha. The results of the present report provide for the first time evidence that tamoxifen might exert a stimulatory effect on the uterus, at least during tumor progression, through ERbeta but not through ERalpha.
Ist Department of Obstetrics and Gynaecology, Aristotle University of Thessaloniki, Hippokrateio General Hospital, Thessaloniki, Greece.
M
M
Zafrakas
E
E
Kostopoulou
K
K
Dragoumis
T
T
Mikos
J
J
Papadimas
J
J
Bontis
D014408:Biomarkers, Tumor / Q000032:analysis; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D002296:Carcinosarcoma / Q000139:chemically induced* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D016889:Endometrial Neoplasms / Q000139:chemically induced* / Q000473:pathology; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008408:Mastectomy / Q000379:methods; D008875:Middle Aged; D009367:Neoplasm Staging; D011960:Receptors, Estrogen / Q000032:analysis* / Q000187:drug effects; D018570:Risk Assessment; D013629:Tamoxifen / Q000009:adverse effects* / Q000627:therapeutic use
D014408:Biomarkers, Tumor; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D011960:Receptors, Estrogen; D013629:Tamoxifen