'Watchful Waiting' Best Approach for Benign Ovarian Cysts

Troy Brown, RN

February 07, 2019

Women with ovarian cysts judged to be benign on ultrasound had a low risk for malignancy when managed conservatively, according to 2-year interim results from an analysis of the International Ovarian Tumor Analysis phase 5 (IOTA5) study.

One of the researchers, Tom Bourne, PhD, Imperial College, London, UK, said the study suggests watchful waiting is appropriate for most women when an ovarian cyst is first classified as benign on ultrasound.

"Our results may lead to a paradigm shift resulting in less surgery for noncancerous ovarian cysts — on condition that trained ultrasound examiners reliably exclude cancer," said Bourne in a news release from his institution.

The study was published online February 5 in Lancet Oncology by Wouter Froyman, MD, of the Department of Obstetrics and Gynecology, University Hospitals Leuven, Belgium, and colleagues.

In an accompanying commentary, Taymaa May, MD, of the Division of Gynecologic Oncology, Princess Margaret Cancer Center, University Health Network, Toronto, Ontario, Canada and colleagues agree. "This study focuses on a crucial topic that affects many women and poses a common challenge in clinical practice...[it] supports conservative management of [ovarian cysts] that are classified as benign on ultrasound imaging," they write.

Most Cysts, 80%, Have Required No Intervention

Opinion is still divided on watchful waiting, with many physicians across the world believing benign ovarian cysts should be surgically removed in the majority of cases, either to prevent serious complications — including rupture or ovarian torsion — and/or because of concerns they could become malignant if not removed or that they were originally misclassified as benign on ultrasound.

Froyman and colleagues note that few large prospective studies on long-term follow-up of ovarian cysts, which are classified as adnexal masses — a lump of tissue near the uterus, most commonly in the ovary or fallopian tube — exist.

"To our knowledge, this is the first multicenter prospective study in this area, and it has the largest number of patients in a study of conservative management of adnexal masses so far," they observe.

IOTA5 is a prospective, multicenter, cohort study of more than 8000 patients in 10 European countries.

The current analysis included 1919 women (average age, 48 years), with at least one newly diagnosed adnexal mass (average size, 4 cm) that was deemed benign on initial ultrasound.

The women were followed up with regular ultrasonography for 2 years at intervals of 3 months, 6 months, and then every 12 months thereafter.

Ultimately, the treating clinician decided on the management plan at each visit. Surgery was performed — according to local practice — either for suspicion of malignancy; pain; or patient request, fertility concerns, or opportunistic or prophylactic removal.

The main outcomes of this 2-year interim analysis were cumulative incidence of spontaneous resolution of the mass, torsion or cyst rupture, or borderline or invasive malignancy confirmed surgically.

One in five (20.2%) of the women had cysts that resolved on their own and 16.1% had surgery.

In 80% of cases ovarian cysts disappeared or required no intervention; the latter means there has been no "flag" on ultrasound that necessitated any intervention, nor any pain, nor patient request for surgery. So the majority of women continue to be monitored by watchful waiting, including regular ultrasound assessments.

Only 12 women were diagnosed with ovarian cancer, for a 2-year cumulative risk of cancer of 0.4%. The researchers believe that in most of these cases, the tumors were initially misdiagnosed as noncancerous on the initial ultrasound scan, rather than being a benign cyst that had turned malignant. 

Two-year cumulative incidence of finding a borderline tumor at surgery was 0.3%, and for torsion, 0.4%, and 0.2% of cysts ruptured.

The researchers say avoiding an operation reduces the risk of short- and long-term surgical complications, such as bowel perforation.

Success Depends on Good Ultrasounds, Longer Follow-Up Needed

The authors of the commentary say longer follow-up of the cohort is needed "to further characterize the natural progression of masses characterized as benign by use of ultrasound," and to see whether or not the incidence of unplanned surgical interventions, complications, or spontaneous resolution increases.

In the meantime, "The knowledge generated from the current trial could add value when counseling women with adnexal masses and could be reassuring to the patient when considering conservative management," they emphasize, cautioning that the "success of such management is dependent on good ultrasonography, and future efforts should continue to strive to improve predictive accuracy."

One author reports receiving grants, personal fees, and travel support from Samsung Medison; travel support from Roche Diagnostics; and personal fees from GE Healthcare, outside the submitted work. The other authors and commentators have disclosed no relevant financial relationships.

Lancet Oncol. Published online February 5, 2019. Abstract, Commentary

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