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Letrozole to Help Prevent Endometriosis Cysts Returning After Ovarian Surgery

Tests letrozole with birth control pills in women with ovarian endometriosis cysts after surgery.

Key facts

Who runs it
The University of Hong Kong
Where
Hong Kong, Hong KongSee the 5 sites
Trial code
Registry title
Letrozole in Preventing Recurrence of Endometrioma Following Laparoscopic Ovarian Cystectomy
Status
Recruiting
People taking part
194 people, planned
Started
1 Dec 2022
Expected to end
30 Jun 2027
Type of study
Interventional, 2 groupsOne group gets a placebo (a dummy treatment), for comparison.
Treatments tested
  • Letrozole
  • Placebo
Record updated
14 May 2024

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for women who are about to have laparoscopic surgery to remove an endometriotic cyst of the ovary. It tests whether letrozole, added to birth control pills, lowers the chance the cyst comes back.

Age
18 to 45 years
Sex
Women only
Disease stage
Endometrioma (endometriotic cyst of the ovary) on one or both sides, seen on ultrasound before surgery and confirmed by tissue examination
Earlier treatment
Must not have used long-acting hormonal therapy in the 3 months before joining

Main reasons for not taking part

  • Atypical endometrioma on the tissue report
  • Complex surgery such as deep disease removal, bowel removal or hysterectomy
  • Suspected cancer
  • Health problems that rule out combined birth control pills
  • Planning to get pregnant within the next year

The registry criteria, word for word

Show all 11 criteriaShow less

Who can take part

  • Women aged 18-45 years old
  • Scheduled to have laparoscopic ovarian cystectomy
  • Unilateral or bilateral endometrioma on pre-operative ultrasound and confirmed by histology

Who cannot take part

  • Use of long-acting hormonal therapy in the 3 months before inclusion in the study
  • Complex surgery including resection of deep infiltrating disease, bowel resection or hysterectomy
  • Suspicion of malignancy
  • Contraindications to combined oral contraceptive pills, including: uncontrolled hypertension (systolic > 160mmHg or diastolic > 100mmHg), diabetes with retinopathy/ nephropathy/ neuropathy, current or past history of venous thromboembolism, ischemic heart disease, history of cerebrovascular accident, migraine with aura, severe liver disease, oestrogen-sensitive cancers, undiagnosed abnormal uterine bleeding, smokers (> 15 cigarettes/day) aged 35 years or above, or having body mass index >=35 kg/m2
  • Histological report of laparoscopic ovarian cystectomy showed atypical endometrioma
  • Incomplete excision of endometrioma/ incision or drainage rather than ovarian cystectomy
  • Planning to get pregnant in the coming 1 year
  • Refusal to join the study

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 18 and 45 years old?

Where in Hong Kong

  • Kwong Wah HospitalHong Kong, Hong KongContact: Mei Ting Lam, MBBSNot yet recruiting
  • Pamela Youde Nethersole Eastern HospitalHong Kong, Hong KongContact: Catherine K.Y. WongNot yet recruiting
  • Princess Margaret HospitalHong Kong, Hong KongContact: Rebecca S.F. Wan, MBBS, MRCOGNot yet recruiting
  • Queen Elizabeth HospitalHong Kong, Hong KongContact: Keedon WongNot yet recruiting
  • Queen Mary HospitalHong Kong, Hong KongContact: Jennifer K.Y. Ko, MBBS, MRCOGTaking people

About the trial

What the trial wants to find out

Endometriosis is a chronic inflammatory disease that affects approximately 10-15% of women of reproductive age. Symptoms include dysmenorrhoea, chronic pelvic pain, dyspareunia and infertility. Removal of the endometriotic cyst (chocolate cyst) by surgery is a well-established treatment for symptomatic relief. However, recurrence of endometriotic cyst after surgical removal of the cyst is up to 30-50% after ovarian surgery. Oral contraceptive pills for 18-24 months after the surgery is widely used as a postoperative hormonal therapy because it has been shown to reduce the chance of recurrence of the endometriotic cyst, but recurrence is still high even after taking oral contraceptive pills.

Read full original descriptionShow less

Letrozole is an aromatase inhibitor. There are some preliminary reports that letrozole can cause shrinkage of endometriotic cysts and improve endometriosis-related pelvic pain by reducing oestrogen level, inflammation and stem cell recruitment that may be important in recurrence of endometriotic cyst. This is a randomized double-blinded placebo-controlled trial. The aim of this study is to assess whether taking letrozole in addition to oral contraceptive pills in the first 6 months after laparoscopic surgery (key-hole surgery) to remove the endometriotic cyst can reduce the risk of recurrence compared to oral contraceptive pills alone. The study also involves laboratory parts from a small portion of the endometriotic cyst specimens (removed during laparoscopy ovarian cystectomy) and endometrial biopsy (if the patient agrees) to assess the role of stem cells in the pathogenesis of endometriotic cysts.

The 2 groups in the trial

  • LetrozoleTreatment being tested

    They will be given letrozole 2.5mg daily on top of combined oral contraceptive (COC) pills (Microgynon 30, which contains 30mcg ethinyloestradiol and 150 mcg levonorgestrel) orally for 6 months after laparoscopic ovarian cystectomy, followed by COC pills alone subsequently as routine

  • Standard treatmentPlacebo, for comparison

    They will be given placebo tablets (which will be identical to letrozole) on top of COC pills (Microgynon 30, which contains 30mcg ethinyloestradiol and 150 mcg levonorgestrel) orally for 6 months after laparoscopic ovarian cystectomy, followed by COC pills alone subsequently

    Treatment: Placebo

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Letrozole in Preventing Recurrence of Endometrioma Following Laparoscopic Ovarian Cystectomy
Plain-language title
Letrozole to Help Prevent Endometriosis Cysts Returning After Ovarian SurgeryGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 12 November 2026.
Fit questions
Built from NCT05487092, who can take part
Record updated
14 May 2024