For women aged 18 years and older who underwent pelvic ultrasonography with transvaginal imaging, the high prevalence of simple ovarian cysts detected was not associated with an elevated relative risk of ovarian cancer; however, complex cysts and solid masses were associated with elevated relative risk, according to a study published in JAMA Internal Medicine.
A team of researchers conducted a nested case-control study to assess ovarian cancer risk based on characteristics of ovarian masses in women who underwent pelvic ultrasonography from January 1997 to December 2008; the study was completed in April 2017.
Ultrasonography results from 72,093 women who were enrolled in Kaiser Permanente Washington, an integrated health care system, were analyzed; ultrasonographic characteristics of ovarian cancer were recorded in 1043 women and frequencies were estimated for all enrolled women.
A total of 210 women were diagnosed with ovarian cancer. Although the majority of the women in the study were younger than 50 years (75.5%), most of the women with ovarian cancer were older than 50 years (76.7%). Women were diagnosed with ovarian cancer an average of 3.4 months after undergoing the primary ultrasonographic examination. Average time between examinations was 11 months for women with ovarian cancer who underwent more than 1 examination; for women who underwent more than 1 examination and were not diagnosed with ovarian cancer, the average time between examinations was 17.2 months.
The researchers reported that most women had normal ovaries. The second most common finding of a simple cyst was estimated to occur in 23.8% of women younger than 50 years and in 13.4% of women aged 50 years and older; of the estimated 15,306 women with a simple cyst, only 1 woman was diagnosed with ovarian cancer.
Of the women diagnosed with ovarian cancer, the most prevalent finding was a complex cystic mass, which was found in 63.3% of women younger than 50 years and 55.9% of women aged 50 years and older. Complex cystic masses were associated with an 8-fold increase in risk of ovarian cancer. The presence of ascites significantly increased the likelihood of cancer in women aged ≥50 years with a complex cyst (likelihood ratio, 74.17).
Solid masses were estimated to occur in nearly 10% of women with ovarian cancer and in approximately 1% of women without ovarian cancer. The presence of a solid mass was associated with an approximately 10-fold increase in the likelihood of cancer (likelihood ratios of cancer were 8.08 and 10.08 for women younger than 50 years and for women aged 50 years and older, respectively).
“According to this study, the ultrasonographic appearance of ovarian masses is strongly associated with a woman’s risk of ovarian cancer,” the authors wrote. “Simple cysts are not associated with an increased risk of ovarian cancer, whereas complex cysts or solid masses are associated with a significantly increased risk of ovarian cancer,” they concluded.
Smith-Bindman R, Poder L, Johnson E, Miglioretti DL. Risk of malignant ovarian cancer based on ultrasonography findings in a large unselected population [published online November 12, 2018]. JAMA Intern Med. doi: 10.1001/jamainternmed.2018.5113