Prevalence, Incidence, and Natural History of Simple Ovarian Cysts Among Women >55 Years Old in a Large Cancer Screening Trial

Abstract

Many simple ovarian cysts are being detected in postmenopausal women with increasing use of transvaginal ultrasound. In the past, aggressive surgical approaches were used for management of simple cysts. Some investigators recommend careful monitoring and others question if simple cysts should be monitored at all. This observational cohort study investigated the occurrence and natural history of simple ovarian cysts within a cohort of 15,535 mostly postmenopausal women in the intervention arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Four annual serial transvaginal ultrasound screening examinations were performed. Simple ovarian cysts were detected in 14% (2217/15,735) of the cohort during the first fully visualized screen of the ovaries (incident cyst). The incidence of new simple cysts during the first year was 8%, and remained relatively constant throughout the course of the trial. At the second ultrasound screen 1 year later, 54% of the ovaries with 1 simple cyst at the first screen retained 1 simple cyst and 32% had no cyst. The presence of simple cysts was not associated with increased risk of subsequent invasive ovarian cancer. These findings show that the occurrence of simple ovarian cysts in postmenopausal women is a common incidental finding on ultrasound, and support recent recommendations that such cysts should be followed in older women without intervention.