[Hormonal therapy of endometrial cancer]

Progestin therapy is indicated for advanced or metastatic endometrial cancer as well as a adjuvant therapy for primary cancer. There are several predictors of tumor responsiveness to the hormone. Sex steroid receptor(R) is a biochemical marker. Receptor analysis was done in 73 cases of primary endometrial cancer. The concentrations of estrogen (E), progestin (P) and androgen (A) were found to correlate with the degree of tumor differentiation; well-differentiated tumor contains significantly greater receptors than moderately-and poorly-differentiated tumors. Both ER and PR were positive in about 80% of the well-differentiated tumor, but negative in 50% of the poorly-differentiated tumors. Analysis of 13 cases of death shows some correlation of the PR concentrations with the survival time. Receptor dynamics in tumor of the patients enables us to predict possible site(s) of impaired responsiveness to progestin. Furthermore, in addition to progestin and estrogen test, tamoxifen challenge test is useful as in vivo sensitivity test. Moreover, receptor manipulation by tamoxifen may be employed to enhance hormonal sensitivity of the tumor, particularly the low receptor one.