Tibolone and risk of endometrial polyps: a prospective, comparative study with hormone therapy.
OBJECTIVE
To assess the incidence of endometrial polyps during postmenopausal replacement therapy with tibolone, using an appropriate control group.


METHODS
A total of 485 postmenopausal women were included in this open, prospective, comparative study for a duration of 36 months. Of this group, 249 women received 2.5 mg/day of tibolone and 244 women served as controls, receiving continuous-combined estrogen-progestogen therapy (HT). Transvaginal ultrasound, hysteroscopy, and directed biopsies were performed before treatment was initiated and at the end of the study.


RESULTS
Two hundred twenty-one of the women receiving tibolone and 203 receiving continuous-combined HT completed the study. Endometrial polyps were detected in 74 women (33.4%) from the tibolone group and in 22 women (10.8%) from the HT group (P < 0.01). The vaginal bleeding rate did not differ between the groups. The frequency of atrophic polyps was significantly higher in the tibolone group (P < 0.01). No difference was found in the size of the polyps.


CONCLUSIONS
Tibolone increases by threefold the risk for endometrial polyps.
Perez-Medina
Tirso
T
Santa Cristina University Hospital, Universidad Autónoma de Madrid, Madrid, Spain. tperezm@meditex.es
Bajo-Arenas
José
J
Haya
Javier
J
Sanfrutos
Luis
L
Iniesta
Silvia
S
Bueno
Beatriz
B
Castelo-Branco
Camil
C
D000328:Adult; D004714:Endometrial Hyperplasia / Q000139:chemically induced*; D020847:Estrogen Receptor Modulators / Q000008:administration & dosage / Q000009:adverse effects*; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009652:Norpregnenes / Q000008:administration & dosage / Q000009:adverse effects*; D011127:Polyps / Q000139:chemically induced*; D017698:Postmenopause; D011446:Prospective Studies; D012307:Risk Factors
D020847:Estrogen Receptor Modulators; D009652:Norpregnenes; C027385:tibolone