Nonsuspicious adnexal masses had a low risk of malignancy, and many of the lesions resolved spontaneously, according to a large prospective study of conservative management.
During a median follow-up of 27 months, fewer than 1% of 1,919 patients had an invasive malignancy or borderline tumor at surgery. Torsion and cyst rupture also occurred in fewer than 1% of cases.
Spontaneous resolution within 2 years occurred in 20.2% of the cases, Dirk Timmerman, MD, of KU Leuven in Belgium, and co-authors reported online in the Lancet Oncology.
Noting that surgical removal of adnexal masses has a complication risk of 3-15% in women ages 50-74, Timmerman said in a statement, “Despite these surgical risks being small, if the women in this age group underwent surgery in our study, then we could speculate that 29 to 123 of them could have suffered severe surgical complications.”
Instead, fewer than 100 patients in the study underwent surgery. The findings suggested that most women with ovarian cysts can be observed safely.
“Our results may lead to a paradigm shift resulting in less surgery for noncancerous ovarian cysts — on condition that trained ultrasound examiners reliable exclude cancer,” said study co-author Tom Bourne, MD, of Imperial College London.
Authors of an accompanying commentary emphasized the need for longer follow-up, but agreed with Timmerman, Bourne, and colleagues that the results support conservative management for adnexal masses that appear benign on ultrasound.
“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,” wrote Taymaa May, MD, and Amit Oza, MD, both of the University of Toronto. “The success of such management is dependent on good ultrasonography, and future efforts should continue to strive to improve predictive accuracy.”
Most women with an adnexal mass undergo surgery because of concern that the mass is malignant or could undergo malignant transformation if not removed, the authors noted in their introduction. A risk of torsion and rupture of cysts also exists. Women with symptomatic adnexal masses likely benefit from surgery or referral to a gynecologic oncologist if malignancy is suspected. Surgery for asymptomatic cysts is costly and carries a risk of complications.
Few studies have accumulated long-term outcome data with conservative management of asymptomatic adnexal masses, the authors continued. The lack of informative evidence has posed a challenge to management of patients with lesions associated with minimal or no symptoms.
Ultrasonography offers a safe and relatively inexpensive approach to help clinicians discriminate between benign and malignant adnexal lesions, said Timmerman and colleagues. No previous studies had examined outcomes of conservative management for adnexal lesions found to be benign by ultrasound.
Investigators in 14 countries enrolled patients in a prospective cohort study of conservative management of adnexal masses newly diagnosed by ultrasonography. Eligible patients were age 18 or older and had at least one mass identified by ultrasonography for surgery or conservative management. Data analysis focused on the patients selected for conservative management, which included clinical follow-up with ultrasound at 3 and 6 months and then every 12 months.
Timmerman and colleagues reported findings from an interim analysis after 2 years of follow-up, and the primary outcomes were the incidence of spontaneous resolution, torsion, cyst rupture, and borderline or invasive malignancy confirmed by surgery.
Patients with a newly diagnosed adnexal mass (n=2,410, including those who did not have complete follow-up) had a median age of 48, and 45% were postmenopausal. In 61% of cases, the dominant mass was a unilocular cyst (single locule, no solid components).
That data showed that one fifth of the masses resolved spontaneously. An additional 16.1% of patients had surgical intervention for various reasons, including 2% who had surgery because of suspected malignancy. All-cause mortality for the cohort was 1.2%.
The remaining key outcomes were as follows:
- Invasive malignancy at surgery: 0.4%
- Borderline tumors: 0.3%
- Torsion: 0.4%
- Cyst rupture: 0.2%
“Our results suggest that the risk of malignancy and acute complications is low if adnexal masses with benign ultrasound morphology are managed conservatively,” the authors concluded. “This information could lead to a reduction in the number of women who undergo surgery for benign adnexal pathology.”
Timmerman reported having no conflicts of interest; Bourne disclosed relationships with Samsung Medison, Roche Diagnostics, and GE Healthcare.
May and Oza reporting having no relevant disclosures.