International Ovarian Tumour Analysis (IOTA) Phase 5: UK Study
Research type
Research Study
Full title
A UK single-centre study on the pre-operative characterisation of ovarian tumours and conservative management of benign-looking adnexal masses
IRAS ID
97899
Contact name
Tom Bourne
Contact email
Sponsor organisation
Imperial College healthcare NHS Trust
Research summary
Research Summary:
The medium to long term behaviour of benign-looking pelvic masses that do not undergo surgery is unknown. It is thought to be rare for these masses to undergo malignant changes. Furthermore they may undergo changes in volume and/or shape that may or may not predict their behaviour. To date, no research has investigated the long-term behaviour of such masses. Consequently, there are no evidence-based guidelines on the optimal management of the majority of ovarian tumours. It is therefore not surprising that clinical practice is highly variable, with some clinicians preferring to operate on virtually any mass. When a clinician decides not to operate, the time intervals selected for follow up scans is arbitrarily chosen. Also, we do have convincing data to suggest that simple cysts are rarely malignant and so it is generally thought that operating on these common tumours is probably not necessary and simply increases costs and may cause harm. Developing new insights into the natural evolution of benign-looking conservatively managed ovarian masses would potentially change the management of women, avoid surgery or even further surveillance and detect cancer earlier or even prevent it for some.
We aim to develop the optimal evidence-based algorithm for the management of all ovarian tumours in order to improve the early detection of ovarian cancer and reduce unnecessary operations. At least 400 patients with an adnexal mass will undergo an ultrasound examination and if no operation is needed they will be followed up for at least 5 years. At each visit the investigator will assess the tumour and decide whether surgery is necessary based on the available information and local protocols. We expect 80-100 masses to be difficult to assess by ultrasound scan only and need magnetic resonance imaging (MRI) for further assessment as per clinical practice.Summary of results:
The IOTA 5 study is part of a multi-centre study that is still ongoing. The UK arm of the IOTA 5 study has now closed.
Ovarian cysts are very common, most are benign (non-cancerous) and can be managed conservatively (expectantly) without the need for intervention. Ovarian cysts are at risk of twisting (torsion) and rupture (opening in the pelvis), which can require an operation (surgery) in an emergency.
The aim of the study was to observe the natural course of ovarian cysts through regular ultrasound surveillance over a five-year period to help guide the best management of ovarian cysts.
Across the IOTA 5 study, 3144 patients were successfully enrolled across 19 centres across the world, 734 patients had an ovarian cyst that was already known about, and 2410 patients had a new ovarian cyst that was identified on ultrasound.
The interim analysis for the two year follow up has been completed.
Most patients with a new ovarian cyst (n=1919) were managed expectantly. Over two years, 20.2% resolved without intervention and 16.1% had surgery (2.0% due to a suspected malignancy). During this 2-year period, 0.4% (n=7) had an ovarian cancer (invasive malignancy), 0.3% (n=5) had a borderline ovarian tumour (a non-invasive type of cancer), 0.4% (n=7) had an ovarian torsion (twisting of the ovary) and 0.2% (n=4) had a cyst rupture (cyst spontaneously opens).
The low risk of complications in a two-year period reinforces the safety of conservative (expectant) management for most ovarian cysts that are thought to be benign (non-cancerous) at initial diagnosis. Although there was a very low rate of malignant transformation, when the initial ultrasound images were reviewed the ovarian cysts were misdiagnosed as benign rather than there being true malignant transformation.
The conclusion from the study is that most ovarian cysts in patients that are not symptomatic can be safely managed without surgical intervention.
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REC name
London - Harrow Research Ethics Committee
REC reference
14/LO/0302
Date of REC Opinion
16 Apr 2014
REC opinion
Further Information Favourable Opinion