Endometrial thickness among BRCA mutation carriers undergoing prophylactic oophorectomy

It has been suggested that women with a pathogenic variant (mutation) in BRCA1 or BRCA2 are at a higher risk of developing high-grade endometrial cancer. Furthermore, significantly higher follicular (but lower luteal) endometrial thickness, a surrogate marker for endometroid adenocarcinoma risk, has been reported for this high-risk population. Given that medications known to affect endometrial thickness (i.e., tamoxifen, oral contraceptives) are often indicated for BRCA mutation carriers, it is important to elucidate substantial differences exist in carriers. Thus, we conducted a retrospective chart review of endometrial thickness among women with a BRCA1 or BRCA2 who had an intact uterus and were referred to a specialized ovarian cancer clinic between 2007 and 2016. Clinical data was collected from chart review, while endometrial thickness (millimeters; mm) was abstracted from transvaginal ultrasound reports with endometrial dating and compared to published levels in the general population. In total, 114 women were identified, 73 of whom were premenopausal and 41 who were postmenopausal. Among premenopausal women, the median follicular endometrial thickness found was 7.00 mm (n = 40, range 3-13) compared to 6.8 mm (range 2.4-14) in non-carriers and the median luteal endometrial thickness was 10.85 mm (n = 30, range 5-18), compared to 9.6 mm (range 3.3-18.2) in non-carriers. Among postmenopausal women, the median menopausal endometrial thickness was 4.0 mm (n = 41, range 1-18) compared to 4.0 mm (range 1-25) in non-carrier controls. Although based on small numbers, we found no significant difference in the endometrial thickness of BRCA mutation carriers versus non-carriers.