Surveillance for Endometrial Cancer in Women on Tamoxifen: The Role of Liquid-Based Endometrial Cytology–Cytohistological Correlation in a Population of 168 Women

Abstract

Tamoxifen has for some time been standard adjuvant therapy in women with endocrine-responsive breast cancer. It does lower the recurrence rate and prolongs disease-free survival, but also appears to entail an increased risk of endometrial cancer. The best means of surveillance for women on long-term tamoxifen therapy has not been established, but 1 option is liquid-based cytology, which is able to reduce obscuring factors including inflammatory cells and blood and which provides a thin-layer endometrial sample. This study compared the diagnostic accuracy of liquid-based cytology with the histological diagnosis in 168 women on tamoxifen therapy who were scheduled for hysteroscopy. Hysteroscopy was followed sequentially by endometrial cytology and biopsy. All procedures were done in an outpatient setting without analgesia, using the Endoflower device for cytological sampling. Endometrial biopsy alone was inadequate in 67% of patients, and both biopsy and cytology in 11%. Endometrial cytology alone was inadequate in only 4 instances (2% of patients). In 20% of the study group, both endometrial biopsy and cytology were adequate. In all, endometrial biopsy proved inadequate in 78% of patients and endometrial cytology in 14%. Cytology provided enough material to reach a diagnosis more often than did endometrial biopsy. When both endometrial cytology and biopsy were adequate, there was complete correlation between the results. Among 28 women with inadequate biopsy and adequate cytology who had further histological assessment was 1 with endometrial adenocarcinoma that was detected only by endometrial cytology. The cytologic diagnosis subsequently was confirmed by endometrial curettage. Liquid-based endometrial cytology appears to be a useful means of endometrial surveillance in women taking tamoxifen. It may be used by itself or in conjunction with transvaginal ultrasonography.