Objectives: To describe the endometrial appearance in postmenopausal breast cancer patients on tamoxifen and to assess a routine surveillance scheme for endometrial lesions.
Study design: Three hundred and seventeen postmenopausal breast cancer women already on tamoxifen at the start of the study (group I) and 89 breast cancer women assessed before any tamoxifen intake (group II) underwent an initial and then yearly scans with transvaginal ultrasonography, followed by an hysteroscopy and biopsy for women with an endometrium thickened above 8mm. Endometrial thickness was also measured in 823 women with no breast cancer nor tamoxifen intake (group III).
Results: Initial mean endometrial thickness was 8.2mm in group I, 4.4mm in group II and 3.4mm in group III (P<0.001). Eighteen percent endometrial lesions were found in group I and 3.3% in group II. We observed a significant association between endometrial pathology and both cumulated dose and total duration. Polyps were the most frequent and first to appear pathology. Five cancers were detected in group I, and all of them had taken tamoxifen for more than 3 years.
Conclusion: Our surveillance scheme could be lightened; an acceptable screening scheme might include a baseline assessment before the start of tamoxifen and, if normal, yearly screening after 3 years of tamoxifen therapy, yearly surveillance for women with an abnormal baseline assessment and immediate investigation for symptomatic women.