Investigation

In suspected endometrial cancer the following investigations are mandatory (1):

• transvaginal ultrasound scan
  • this technique has a negative predictive value approaching 100% for the exclusion of endometrial cancer - however sensitivity depends on the cut-off used for normal endometrial thickness (2)
    • meta-analysis of 35 studies (using a 5mm threshold to define abnormal endometrial thickening) reveled that around 96% of women with cancer had endometrial thickness greater than 5 mm;
  • meta-analysis data have also shown that:
    • endometrial thickness of less than 4-5 mm in the presence of endometrial pathology poses a very low but not negligible risk of malignancy (not applicable to patients who are on regular HRT or tamoxifen for breast carcinoma)
    • specificity of an abnormal transvaginal ultrasound result dropped from 92% to 77% when used in patients on HRT.
      • in asymptomatic patients the upper endometrial thickness limit is 8 mm, but if vaginal bleeding is present a biopsy should be taken if the thickness is greater than 5 mm.
  • European guidelines have a lower cut-off point of ≤3 mm, followed by endometrial sampling (3)
  • with respect to transvaginal ultrasound, the value of endometrial thickness in perimenopausal bleeding is questionable as the range of thickness is so variable
    • hysteroscopy should be also considered if the endometrium is difficult to identify
• an endometrial biopsy
  • a tissue sample obtained through Pipelle curette (in the gynaecology outpatient setting) or by hysteroscopy and dilatation and curettage under general anaesthesia can be used
  • useful in diagnosing rather than excluding cancer (1,3)

Notes:

• some pathology may be missed and it is recommended that hysteroscopy and biopsy should be performed if clinical suspicion is high.
• other causes of post-menopausal bleeding should be considered whilst remembering that innocent and malignant lesions may co-exist

Reference:

• (1) Saso S et al. Endometrial cancer. BMJ. 2011;343:d3954
• (2) Bailey J, Murdoch J (2004).Endometrial cancer.Current Obstetrics & Gynaecology;14(5): 337-342.
• (3) Colombo N et al. Endometrial cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2013;24 Suppl 6:vi33-8