What is the management for a postmenopausal female with an incidental finding of endometrial thickness (ET) of 7 mm on ultrasound in the absence of vaginal bleeding?

From the Guidelines

For a postmenopausal woman with an incidentally discovered endometrial thickness of 7 mm on ultrasound without vaginal bleeding, no immediate intervention is necessary, as the risk of endometrial cancer is low in asymptomatic women. According to the American College of Radiology 1, an endometrial thickness of 4 mm in a postmenopausal woman conveys a negative predictive value for cancer of nearly 100%. Although the endometrial thickness in this case is slightly higher, at 7 mm, it is still considered within acceptable limits for asymptomatic postmenopausal women.

The management approach should focus on close follow-up with a repeat ultrasound in 3-6 months to monitor for any changes 1. The patient should be advised to report any vaginal bleeding immediately, as this would change the management approach and necessitate further evaluation with endometrial biopsy 1. Endometrial thickening can occur due to benign causes such as endometrial polyps, atrophy with fluid collection, or hormone replacement therapy.

Key considerations in the management of this patient include:

• Assessing risk factors such as obesity, diabetes, hypertension, or family history of endometrial or colon cancer, as their presence might lower the threshold for further investigation even in asymptomatic women 1
• Monitoring for any changes in endometrial thickness on follow-up ultrasound 1
• Advising the patient to report any vaginal bleeding immediately, which would prompt further evaluation with endometrial biopsy 1
• Considering the use of transvaginal ultrasound (TVUS) as the first-line screening test for endometrial cancer in postmenopausal women, particularly in those with vaginal bleeding 1.

From the Research

Endometrial Thickness Threshold

• The threshold for endometrial thickness in postmenopausal women without vaginal bleeding is a topic of discussion in various studies 2, 3, 4, 5.
• A study published in 2004 suggests that an endometrial thickness of > 11 mm should prompt biopsy in postmenopausal women without vaginal bleeding, as the risk of cancer is approximately 6.7% 2.
• Another study from 2016 found that an endometrial thickness of > 11 mm seems realistic to use as a cut-off for referral for hysteroscopy, with a risk estimate for endometrial cancer of 9.1% 3.
• However, a 2016 study published in the International Journal of Gynaecology and Obstetrics suggests that an endometrial thickness of ≥ 15 mm is associated with carcinoma, with a negative predictive value of 98.5% and a 0.06% risk of cancer 4.
• A more recent study from 2019 suggests a cutoff value of 10.5 mm for endometrial thickness, recommending hysteroscopy following dilatation and curettage to increase diagnostic efficacy and provide definitive treatment in asymptomatic postmenopausal women with thickened endometrium 5.

Risk of Cancer

• The risk of cancer in postmenopausal women without vaginal bleeding and an endometrial thickness of 7 mm is not explicitly stated in the provided studies.
• However, based on the study by 2, an endometrial thickness of < 11 mm is associated with a low risk of cancer (approximately 0.002%).
• Given that the endometrial thickness in this case is 7 mm, which is below the threshold of 11 mm, the risk of cancer is likely to be low.

Recommendations

• Based on the available evidence, it is likely that no immediate action is required for a postmenopausal woman without vaginal bleeding and an endometrial thickness of 7 mm.
• However, it is essential to consider individual patient factors and clinical judgment when making decisions about further evaluation or treatment 2, 3, 4, 5.