Guideline No. 451: Asymptomatic Endometrial Thickening in Postmenopausal Women

Objective

To formulate strategies for clinical assessments for endometrial thickening on ultrasound in a postmenopausal woman without bleeding.

Target population

Postmenopausal women of any age.

Outcomes

To reduce unnecessary invasive interventions and investigations in women with asymptomatic endometrial thickening while selectively investigating women at risk for endometrial cancer.

Benefits, harms, and costs

It is anticipated that the adoption of these recommendations would save postmenopausal women unnecessary anxiety, pain, and risk of procedural complications. It is also expected to decrease the cost to the health care system by eliminating unnecessary interventions.

Evidence

English language articles from Medline, Cochrane, and PubMed databases for relevant peer-reviewed articles dating from 1995 to 2022 (e.g., asymptomatic endometrial thickness, endometrial cancer, postmenopausal bleeding, transvaginal ultrasound, endometrial biopsy, cervical stenosis, hormone therapies and the endometrium, tamoxifen, tibolone, aromatase inhibitors). Results were restricted to systematic reviews and meta-analyses, randomized controlled trials/controlled clinical trials, and observational studies.

Validation Methods

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).

Intended Audience

Physicians, including gynaecologists, obstetricians, family physicians, radiologists, pathologists, and internists; nurse practitioners and nurses; medical trainees, including medical students, residents, and fellows; and other providers of health care of the postmenopausal population.

Social Media Abstract

Postmenopausal women often have a thickening of the lining of the uterus found during ultrasound. Without bleeding, an endometrium <11 mm is rarely a serious problem but should be evaluated by a health care provider.

SUMMARY STATEMENTS

• 1.

  Asymptomatic endometrial thickening >5 mm is found in 3%–15% of postmenopausal women depending on the population studied (moderate).

• 2.

  Ninety percent of postmenopausal women with endometrial cancer present with bleeding (high).

• 3.

  In postmenopausal women without bleeding and an endometrium <11 mm, the incidence of endometrial cancer is approximately 1% (high).

• 4.

  Endometrial biopsy is an accurate procedure if an adequate tissue sample is obtained in a patient with global thickening (high).

• 5.

  Hormone replacement therapies, if used in a continuous combined formulation, do not increase the risk of uterine cancer (high).

• 6.

  Women prescribed tamoxifen do not require screening ultrasound examinations (high).

• 7.

  Cervical stenosis may complicate the ability to obtain an adequate endometrial pathological sample (high).

RECOMMENDATIONS

• 1.

  Indications for endometrial tissue sampling in patients presenting with postmenopausal bleeding should not be extrapolated to asymptomatic women (strong, high).

• 2.

  A woman who has an endometrial thickness >11 mm and/or other positive findings on ultrasound, such as increased vascularity, inhomogeneity of the endometrium, or particulate fluid, should have endometrial sampling or be referred to a gynaecologist for further investigations (strong, moderate).

• 3.

  Further investigations should be made on an individual basis in asymptomatic women with increased endometrial thickening and risk factors for endometrial cancer, such as obesity, hypertension, late menopause, unopposed estrogen use, and genetic cancer risks (conditional, moderate).

• 4.

  Postmenopausal women without bleeding, no risk factors, and a global endometrial thickening of <11 mm do not require invasive investigations (strong, moderate).

• 5.

  Transvaginal ultrasound should not be used as a screening tool for endometrial cancer (strong, moderate).

• 6.

  In asymptomatic women with endometrial thickening >11 mm and insufficient endometrial sampling, further investigations should include hysterosonogram, diagnostic hysteroscopy, dilation and curettage, or watchful monitoring (conditional, low).

• 7.

  Women taking hormone therapy in a continuous combined formulation without bleeding do not require screening ultrasounds (strong, high).

• 8.

  Women who are amenorrheic on hormone therapies and develop new bleeding should be investigated (strong, low).

• 9.

  Asymptomatic women on tamoxifen should not receive routine/screening ultrasound (strong, high).

• 10.

  Women with cervical stenosis and no bleeding should be managed individually depending on the endometrial thickness, appearance of the endometrium on ultrasound, and the patient’s individual risk factors (strong, low).