Managing Adnexal Masses in Older Women: Striking the Right Balance

Posted 2 days ago by Caitlin Horsham

Managing adnexal (ovarian and fallopian tube) masses is a frequent challenge for gynaecologists. The detection of these masses often raises concerns about ovarian cancer, especially in older women. While surgery is the only definitive way to rule out cancer, not all women need it, as most adnexal masses are benign. The key challenge lies in balancing the risk of delayed cancer diagnosis with the risks of unnecessary surgery, which can result in complications for up to 15% of patients.

When signs of malignancy are not present—such as no ascites or elevated CA-125 tumour marker—monitoring with repeat ultrasounds is a reasonable alternative to surgery for smaller, asymptomatic adnexal masses that appear benign or indeterminate on initial imaging. Since malignant tumours tend to grow or change in appearance over time, stable imaging results typically indicate a benign mass. However, a common question is: How long should a mass be observed to be certain it’s not cancer?

The American College of Obstetricians and Gynecologists’ (ACOG) guidelines suggest repeat ultrasounds when the diagnosis is uncertain and ovarian cancer remains a differential. However, there is no consensus on the ideal interval and duration for follow-up. To address this uncertainty, a study evaluated ovarian cancer risk in a large community-based cohort of women over 50 years who had stable adnexal masses on ultrasound. The goal was to assess how cancer risk changes over time as the masses remain stable.

Study Overview

The study included women aged 50 years and older who had an abnormal adnexal mass detected by pelvic ultrasound between 2016 and 2020. The initial ultrasound reporting the abnormality was considered the baseline, and any prior pelvic ultrasounds or patients with elevated CA-125 or genetic predispositions to ovarian cancer were excluded. The primary outcome measured was the incidence of ovarian cancer, with stability defined as no increase in size greater than 1 cm and no change in the ultrasound characteristics over time.

Key Findings

Among the 4,750 women who were monitored with repeat ultrasounds, 85% had stable masses on follow-up ultrasound, while 15% had masses that were classified as unstable. The overall incidence of ovarian cancer among women with stable masses was very low—just 0.27%. In contrast, those with unstable masses had a higher cancer risk of 1.73%. The longer a mass remained stable, the lower the risk of ovarian cancer. After 12 months of stability, no cancer cases were observed in the cohort. For women whose masses were stable for 6–12 weeks, the risk of cancer was 0.73 cases per 1,000 person-years, while for those with masses stable for 53–104 weeks, the risk dropped to zero. Additionally, the study found that repeat ultrasounds to detect one case of ovarian cancer would need to be performed on 369 women with stable masses at 6–12 weeks, increasing to 1,142 women if the mass was stable for more than 52 weeks. These numbers suggest that long-term follow-up for stable masses may offer minimal benefit.

What does this mean for patients?

The findings suggest that women over 50 years with stable adnexal masses have a very low risk of developing ovarian cancer. In fact, the longer a mass is stable, the lower the likelihood of it being malignant. For women with stable masses for more than 12 months, the risk of ovarian cancer becomes negligible, supporting the idea that continued ultrasound surveillance may not be necessary after that time. In addition to the low risk of cancer, there are potential harms associated with repeated ultrasounds. Patients often experience anxiety when undergoing follow-up imaging, and incidental findings can lead to unnecessary surgeries. Even for benign conditions, surgery carries significant risks, such as bleeding, infection, and injury to surrounding organs. For patients who are candidates for conservative management of adnexal masses, these findings provide reassurance that ultrasound monitoring beyond 12 months may not be necessary, reducing the burden of unnecessary follow-up and surgery.

Conclusion

For women aged 50 and older with stable adnexal masses, the risk of ovarian cancer is very low, particularly after 12 months of demonstrated stability. These findings support a more conservative approach to managing stable adnexal masses, suggesting that continued ultrasound monitoring beyond a year may have limited value. This approach could help reduce unnecessary surgeries and the anxiety associated with repeat imaging, improving the overall quality of care for patients.