Aromatase inhibitors reverse tamoxifen induced endometrial ultrasonographic changes in postmenopausal breast cancer patients.
OBJECTIVE
Aromatase inhibitors may decrease endometrial thickness in breast cancer patients previously having short-term tamoxifen treatment. There is a necessity to find out if aromatase inhibitors can also decrease endometrial thickness in patients previously treated with long-term tamoxifen treatment.


METHODS
Prospective comparison of the last ultrasonographic endometrial thickness measurement taken before discontinuation of long-term tamoxifen treatment in 36 postmenopausal breast cancer patients, with further measurements, performed following aromatase inhibitors administration.


RESULTS
There was a significant decrement of endometrial thickness, following 36.2 +/- 16.8 months of tamoxifen treatment, from a mean value of 9.1 +/- 5.8 mm, measured at the last ultrasonographic measurement performed before discontinuation of tamoxifen treatment, down to a mean value of 6.0 +/- 5.0 mm, measured following 5.8 +/- 5.8 months of aromatase inhibitors therapy (P = 0.001). A second ultrasonographic measurement performed in 8 patients following of additional 7.5 +/- 4.0 months of aromatase inhibitors treatment revealed further decrement of mean endometrial thickness to 4.8 +/- 2.1 mm (P = 0.002 compared to baseline). In 28 patients (77.8%), endometrial thickness was reduced following the administration of aromatase inhibitors, in four patients (11.1%) there was no change in endometrial thickness and four (11.1%) patients demonstrated an increase of endometrial thickness.


CONCLUSIONS
Aromatase inhibitors may reverse endometrial thickening induced by long-term tamoxifen treatment in postmenopausal breast cancer patients.
Markovitch
O
O
Department of Obstetrics and Gynecology, Meir Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Kfar-Saba 44281, Israel.
Tepper
R
R
Fishman
A
A
Aviram
R
R
Cohen
I
I
D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D004717:Endometrium / Q000000981:diagnostic imaging / Q000187:drug effects*; D005260:Female; D006801:Humans; D017698:Postmenopause; D020845:Selective Estrogen Receptor Modulators / Q000009:adverse effects*; D013629:Tamoxifen / Q000009:adverse effects*; D014463:Ultrasonography
D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen