Watchful waiting is a safe and appropriate approach to the management of adnexal ovarian masses with benign ultrasound morphology, according to the largest study to date on the management of benign ovarian cysts.
The International Ovarian Tumor Analysis Phase 5 (IOTA5) study included almost 2000 women recruited from 36 centres in 14 countries, including the United Kingdom.
The findings, published in the Lancet Oncology, show that, among 1919 patients presenting with a new mass at recruitment, the cumulative incidence of spontaneous resolution within 2 years was 20.2% (95% CI, 18.4-22.1). Approximately 16% eventually underwent surgery.
At a median follow-up of 27 months, the cumulative incidence of invasive malignancy at surgery was 0.4% (95% CI, 0.1-0.6) and borderline tumour was 0.3% (95% CI,
Twelve women were subsequently diagnosed with ovarian cancer, making the risk for cancer 0.4%.
Professor Tom Bourne, lead IOTA5 researcher from Imperial College London, said the study suggests watchful waiting is suitable for most women when an ovarian cyst is initial classified as benign on ultrasound.
"Our results may lead to a paradigm shift resulting in less surgery for non-cancerous ovarian cysts - on condition that trained ultrasound examiners reliably exclude cancer," he said.