Ovarian cancer screening ineffective, preemptive surgery can reduce risk

Key takeaways :

• The CA 125 serum test and pelvic ultrasound cannot screen for ovarian cancer.
• Average-risk women can greatly reduce their risk with fallopian tube removal.
• Minimally invasive screening tests are in development.

PHILADELPHIA — Current ovarian cancer screening methods are ineffective, but women can reduce their risk for ovarian cancer with opportunistic salpingectomy — removing the fallopian tubes at time of other surgeries, according to a presenter.

Ovarian cancer has one of the highest cancer-related mortality rates, according to Mitchell Clark, MD, FRCSC, assistant professor in the division of gynecologic oncology in the department of obstetrics, gynecology and reproductive sciences at Yale University School of Medicine.

When detected in its earliest stages, ovarian cancer has a 5-year survival rate of 75% to 90%. However, most ovarian cancers are detected in later stages, when the 5-year survival rate is about 30%.

“Unfortunately, we still do not have an approved, effective test to screen for or detect ovarian cancer in its earliest stages when we can intervene and improve survival,” Clark told Healio. “Despite this, we do have a number of strategies that can reduce a woman’s risk of developing ovarian cancer through genetic screening and/or risk-reducing surgeries.”

Clark warned against trying to predict risk with the cancer antigen 125 blood test (CA 125), which is FDA approved only to monitor response to treatment for ovarian cancer.

“There [are] strong data against the use of routine CA 125 [blood test] and pelvic ultrasound — which many general practitioners use incorrectly — as screening,” Clark told Healio. “These tests, when used inappropriately, provide a false sense of assurance, increase patient anxiety and lead to unnecessary surgery that comes with risks.”

Ovarian cancer likely originates in the fallopian tubes, and that insight should shape research and risk-reduction strategies, Clark said. Currently, salpingectomy is the preferred approach for high-risk women with BRCA1 and BRCA2 genes.

In addition, “I also hope [meeting attendees] will be impressed by the risk reduction for ovarian cancer that comes from opportunistic salpingectomy in average risk women,” Clark said. “This is the idea of removing the fallopian tubes at time of other surgeries, such as hysterectomy, sterilization, etc., and the data suggest a significant reduction [up to 70%] in ovarian cancer risks among these women.”

Noninvasive screening tests are on the horizon, Clark said during the presentation at the Annual Meeting of The Menopause Society. Minimally invasive genetic tests using a Pap smear-like technique, such as PapGene, can detect gene alterations associated with endometrial and ovarian cancers. Another test, PapSEEK, detects circulating tumor DNA in blood and uterine fluid samples.

“We really are looking forward to seeing how this evolves as they continue to scale this up to large-scale multi-institutional trials,” Clark said.

Micro-RNA tests are also in development to identify noncoding RNAs that interact with micro-RNA to dysregulate cell growth early in cancer formation. Micro-RNAs are “highly tissue-specific” and can point to the tissue of cancer origin, Clark said.

Finally, tests that detect methylation of DNA — alterations in gene expression — may serve as biomarkers for ovarian cancer risk.

“We are moving closer to our goal of a simple and effective screening test, but we are still not there yet,” Clark told Healio.