Transvaginal sonography accepted by women with PMB if high endometrial Ca detection rate

A recent cross-sectional questionnaire study has shown that women with postmenopausal bleeding (PMB) would select transvaginal sonography to measure endometrial thickness (TVS-ET) over gold-standard hysteroscopy with biopsy if TVS-ET achieved a median endometrial cancer detection rate of 95.0 percent.

The results also revealed previous hysteroscopy experience as the only factor associated with the women’s requirement for higher endometrial cancer detection rate with TVS-ET. In addition, a substantial proportion of women would accept TVS-ET with an endometrial thickness (ET) cut-off value of 3 mm as the sole method for PMB assessment. [Hong Kong Med J 2022;28:133-139]

While hysteroscopy with biopsy is the gold standard for endometrial examination in women with PMB, the invasive procedure may require the use of anaesthetics and is associated with an increased risk of complications, including uterine perforation. [Lancet 2016;387:1094-1108; Eur J Obstet Gynecol Reprod Biol 2020;252:70-81] TVS-ET is a first-line noninvasive evaluation tool, but consensus is lacking on the ET cut-off that constitutes abnormality. Increasing the cut-off value of ET may increase the risk of false-negative results. [Obstet Gynecol 2018;131:e124-e129]

“In this study, we determined the extent to which women would accept the risk of missing a diagnosis of endometrial cancer if they were to undergo TVS-ET as the first PMB assessment,” noted the investigators from the Chinese University of Hong Kong.

Among 200 women with PMB (mean age, 55.7 years; spotting, light or moderate bleeding, 73.5 percent; single episode of bleeding, 51.5 percent) referred to a university gynaecology unit from June 2016 to June 2017, 11 (5.5 percent) were subsequently diagnosed with endometrial cancer (n=9), cervical cancer (n=1) or atypical hyperplasia (n=1).

The results showed that a median endometrial cancer detection rate of 95.0 percent (interquartile range [IQR], 80–99.9 percent) was required for women to select TVS-ET over hysteroscopy with biopsy. Notably, 77 women (38.5 percent) would accept TVS-ET only if the endometrial cancer detection rate was 99.9 percent – a rate comparable to diagnostic hysteroscopy.

In univariate analysis, the median acceptable endometrial cancer detection rate was significantly higher in women with previous hysteroscopic examination (n=23; median, 99.9 percent; IQR, 90.0–99.9 percent) vs those without (n=177; median, 95.0 percent; IQR, 80.0–99.9 percent) (p=0.047). These findings indicated that women with previous hysteroscopy experience preferred hysteroscopy assessment, unless TVS-ET could provide an endometrial cancer detection rate nearly identical to that with hysteroscopy plus biopsy.

However, the median acceptable detection rate did not significantly increase in women with other prior examinations, including transvaginal ultrasound (p=0.535) and endometrial sampling (p=0.510). Neither PMB episode number (p=0.251) nor severity (p=0.294) in the study cohort was associated with the acceptable detection rate.

The endometrial cancer detection rate of TVS-ET is determined by the ET cut-off value. A previous study showed that TVS-ET with ET cut-off values of 3 mm, 4 mm and 5 mm provided detection rates of 97.0 percent, 94.1 percent and 93.5 percent, respectively. [BJOG 2016;123:439-446]

“With an acceptable endometrial cancer detection rate of 95.0 percent, a substantial proportion of women would select TVS-ET with an ET cut-off value of 3 mm as the sole method for PMB assessment,” the researchers noted. “Clinicians should incorporate patient preferences on PMB investigation to enable informed choices about invasive testing to exclude endometrial cancer.”