Annual ultrasound screening of asymptomatic women at risk of epithelial ovarian cancer can lead to lower staging of cancer at detection and improved survival, compared with no screening, according to a prospective clinical trial that followed more than 46,000 women over 2 decades.
“The findings of this study support the concept that a major predictor of ovarian cancer survival is stage at detection,” said John R. van Nagell Jr., MD, of the University of Kentucky–Markey Cancer Center, Lexington, and his coauthors. “The 10-year survival of women whose ovarian cancer was detected at an early stage (I or II) was 35% higher than that of women diagnosed with stage III cancer.” Study results were published in the November issue of Obstetrics & Gynecology.
The study evaluated 46,101 women enrolled in the University of Kentucky Ovarian Cancer Screening Trial over 30.5 years. Trial participants, all of whom had annual ultrasound screening, were age 50 and older, or 25 and older with a family history of ovarian cancer. Overall, 23% and 44% of the women had a family history of either ovarian or breast cancer, respectively. Women in the study had an average of seven scans each. The unscreened comparator group was women with ovarian cancer referred to the UK Markey Cancer Center.
The study detected 71 cases of invasive epithelial ovarian cancers and 17 epithelial ovarian tumors of low malignant potential. None of the women with these tumors had a recurrence. Among the invasive cancers, the majority were either stage I (42%) or II (21%), and none were stage IV. The median age of these patients was 66 years. Of the low-malignancy tumors, 27% were stage I and 73% stage II, with none stage III or IV. A total of 699 women (1.5%) with persistent ovarian tumors had surgery.
Screened women also had improved survival compared to unscreened women: 86% vs. 45% at 5 years, 68% vs. 31% at 10 years (P less than .001).
However, the study also showed a high overall incidence rate for ovarian cancer, including false-positive and false-negative cases, compared with National Cancer Institute reports in the Kentucky state cancer profile: 271 per 100,000 vs. 10.4/100,000.
The study also looked at the economics of annual screening. “Ovarian screening reduced the 10-year mortality by 37% and produced 416 life years gained,” Dr. van Nagell and his coauthors said. Based on an estimated cost of $56 for each transvaginal ultrasound scan, that translates into a cost of $40,731 for each life year gained.
One concern of screening ultrasound is the high false-positive rate. “Although the sensitivity of transvaginal ultrasonography in detecting an ovarian abnormality is high, it has been unreliable in differentiating benign from malignant ovarian tumors,” they said. While they noted the accuracy of assessing malignancy has improved, the risk of complications in women who have surgery for benign tumors is an ongoing concern. “Additional research is necessary to identify high-risk populations who will benefit most from screening.”
Dr. van Nagell and his coauthors reported having no financial relationships. The study was supported by research grants from the Kentucky Department of Health and Human Services and the Telford Foundation.
SOURCE: Van Nagell JR Jr et al. Obstet Gynecol. 2018 Nov;132[5]:1091-100. doi: 10.1097/AOG.0000000000002921.