Key messages from scientific research that's ready to be acted on
Got It, Hide thisHenderson JT, Webber EM, Sawaya GF. Screening for ovarian cancer: updated evidence report and systematic review for the US Preventive Services Task Force. JAMA. 2018;319:595-606.
Grossman DC, Curry SJ, Owens DK, et al. Screening for Ovarian Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA. 2018;319:588-94.
In women at average risk who do not have symptoms, what are the benefits and harms of screening tests for ovarian cancer?
Ovarian cancer is a common cause of cancer death in women over 45 years of age. Women with early-stage ovarian cancer may not have any symptoms. This is a serious problem because by the time symptoms develop (e.g., persistent abdominal pain or pressure, bloating, constipation, urinary symptoms, back pain, or fatigue), the cancer has often spread beyond the ovaries. Early detection of ovarian cancer with an ultrasound or blood test may improve success of treatments. However, some women who do not have ovarian cancer will have a positive screening test result and may have surgery when they don’t need it. This exposes them to potentially serious complications without any benefit.
Researchers in the USA did a systematic review of studies available up to November 2017. They found 4 randomized controlled trials of 293,587 women who were 45 years or older.
The key features of the RCTs were:
Screening for ovarian cancer did not reduce deaths due to ovarian cancer compared with no screening.
After 2 to 11 years of annual screening, up to 44% of women had at least 1 false-positive test result.
Up to 3% of women with a false-positive test result had unnecessary surgery.
Why does screening for ovarian cancer not work?
There are two reasons: (1) early-stage ovarian cancer usually does not cause symptoms, so women don’t know they have a problem; and (2) the tests we currently have are not very good at detecting early-stage ovarian cancer (i.e., they often indicate cancer is present when it is not). In late-stage ovarian cancer, the symptoms—persistent abdominal pain or pressure, bloating, constipation, urinary symptoms, back pain, or fatigue—are nonspecific. This means they are more common in women who do not have ovarian cancer. For this reason, doctors may miss the diagnosis.
In women at average risk for ovarian cancer (no family history of ovarian or breast cancer) who do not have symptoms, screening is not recommended.
Outcomes | Number of trials (number of women) | Effects of screening |
Death | 3 trials (293,038 women) | Death due to ovarian cancer was not reduced in women screened each year at 3 to 12 years of follow-up. |
False-positive test results | 3 trials (293,038 women) | Up to 44% of women screened each year for up to 11 years had at least 1 positive test but did not have ovarian cancer. |
Surgery | 3 trials (293,038 women) | Between 1% and 3% of women who had a positive screening result had surgery but no cancer was found. |