Recurrence of Endometriosis: A randomised controlled trial of clinical and cost-effectiveness of Gonadotrophin Releasing Hormone Analogues with add-back hormone replacement therapy versus repeat Laparoscopic surgery(REGAL trial) (REGAL)

Research summary

Endometriosis is a common condition which affects one in ten women from puberty to menopause. It causes pelvic pain, poor quality of life and reduces work productivity. It occurs when cells similar to those lining the womb grow outside it, generally within the pelvis. These cells cause internal bleeding at the time of periods, scarring and pain. The condition is diagnosed by laparoscopy (key hole surgery) to identify areas of endometriosis which can be destroyed or removed. Surgery may not provide lasting relief and pain can return in up to half of treated women within five years. Following surgery, women who are not trying to get pregnant are offered the combined oral contraceptive pill or other contraceptives containing hormones called progestogens. Despite surgery and hormonal contraceptives, about two in three women will require further surgery to treat pain due to endometriosis that has come back. A less invasive way of shrinking endometriosis is to use a drug called gonadotrophin releasing hormone analogue (GnRHa) which temporarily stops the ovaries from producing oestrogen. While very effective in terms of reducing pain, this treatment is generally only used for six months to a year because of side effects such as hot flushes and night sweats caused by the lack of oestrogen, and concerns about osteoporosis (thinning of the bones). Recent research has shown that adding small doses of hormone replacement therapy (HRT) in women on GnRHa reduces the risk of side effects and osteoporosis without causing pain to return. An effective long-term non-surgical treatment for endometriosis has been identified as a research priority by patients and clinicians, but to date there have been no long-term comparisons. The REGAL trial will compare long-term (two years) GnRHa with added HRT to key hole surgery in women who experience recurrence of pain after endometriosis surgery.

Principal Investigator

Prof Christian M Becker

Contact us

Email: osprea@wrh.ox.ac.uk

IRAS number

271703