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Society of Gynecologic Oncology outlines recommendations for ovarian cancer prevention

The Society of Gynecologic Oncology released several recommendations intended to help women reduce their risk for ovarian cancer.

Advances in the understanding of ovarian cancer biology and molecular etiology created a need for strong recommendations, according to the clinicians who created them.

“We are interested in the prevention of ovarian cancer,” Joan L. Walker, MD, of Stephenson Cancer Center at University of Oklahoma Health Sciences Center, told HemOnc Today. “Too few women are being tested for genetic cause so that their family members can get tested later and seek prophylactic prevention surgery.”

The recommendations include:

  • Women with epithelial ovarian cancer should undergo genetic testing. This should include testing for BRCA1 and BRCA2 genes, which increase the lifetime risk for ovarian and breast cancers, so patients’ family members can proceed with testing or counseling about risk-reduction strategies if warranted.
  • Oral contraceptives can reduce the risk for ovarian cancer among average-risk women, as well as BRCA mutation carriers. Women should receive counseling about contraindications and side effects to help them weigh potential risks vs. benefits.
  • Women at increased genetic risk for ovarian cancer should undergo risk-reducing salpingo-oophorectomy, or surgical removal of the ovaries, between ages 35 and 40 years.
  • Women at increased genetic risk for ovarian cancer who do not wish to undergo salpingo-oophorectomy should consider salpingectomy — surgical removal of a fallopian tube — once they are done having children.
  • Women at average risk for ovarian cancer who undergo hysterectomy, other pelvic surgery or sterilization should consider salpingectomy if they are done having children.

Two distinct forms of ovarian cancer are recognized. Type 1 tumors tend to present at earlier stages and with less frequency, whereas type 2 tumors tend to present at later stages and lead to the majority of ovarian cancer-related deaths.

Researchers believe that salpingectomy could reduce the risk for type 2 ovarian cancers, given evidence that the majority of type 2 cancers develop from neoplastic progression of epithelial cells in the fallopian tube.

“Currently, there are no recommendations for the prevention of ovarian cancer in the general population because it is a relatively rare cancer,” Walker and colleagues wrote. “Our new understanding of the role of the fallopian tube in the etiology of ovarian cancer has led us to propose the opportunistic removal of the fallopian tubes for the goal of preventing ovarian cancer.”

The use of oral contraceptives can reduce the average woman’s lifetime risk for ovarian cancer by 40% to 50%. A meta-analysis by Iodice and colleagues, who reviewed 18 retrospective and case–control studies, showed BRCA1 and BRCA2 mutation carriers who used oral contraceptives reduced their risk for ovarian cancer by half (summary relative risk = 0.5; 95% CI, 0.33-0.75). Longer duration of use conferred additional benefit (summary relative risk for each additional 10 years of use = 0.64; 95% CI, 0.53-0.78).

Prior research showed salpingo-oophorectomy is the most highly effective method for ovarian cancer risk reduction in women with BRCA1 or BRCA2 mutations. Studies identified by the recommendations’ authors indicated a 70% to 85% risk reduction for ovarian cancer, a 37% to 54% risk reduction for breast cancer, and risk reductions for cancer-related mortality.

“Women should take control of their health, maintain normal body weight, exercise and remain on birth control pills under they reach the end of their childbearing years,” Walker told HemOnc Today. “It is important to keep track of your family history, know your risk and take steps to reduce risk.”

Advances in understanding of risk-reduction strategies must be balanced with potential risks, Otis W. Brawley, MD, FACP, chief medical officer of the American Cancer Society and a HemOnc Today Editorial Board member, wrote in an accompanying editorial.

“Almost every medical intervention can cause some harm,” Brawley wrote. “In evaluating a preventive intervention, one must speak to the associated harms and the benefits-to-harm ratio. This is often difficult because the metrics of measurement can be very different.”

About 1.3% of women will develop ovarian cancer in their lifetimes. Given the relative rarity of the malignancy, the recommendations will have the greatest impact if they are focused on those at greatest risk for ovarian cancer, Brawley wrote.

The SGO’s recommendation that all women diagnosed with ovarian cancer be referred to a genetic counselor for consideration of genetic testing and family counseling is “prudent,” Brawley added.

“Genetic testing should occur only after genetic counseling,” Brawley wrote. “Physicians in general are not trained to explain genetic risk and implications to patients. This understanding is necessary if patients are to make truly informed decisions about preventive interventions.” – by Cameron Kelsall

References:

Brawley OW. Cancer. 2015;doi:10.1002/cncr.29347.

Iodice S, et al. Eur J Cancer. 2010;doi:10.1016/j.ejca.2010.04.018.

Walker JL, et al. Cancer. 2015;doi:10.1002/cncr.29321.

For more information:

Joan L. Walker, MD, can be reached at Stephenson Cancer Center, University of Oklahoma Health Sciences Center, 800 N East 10th Street, Oklahoma City, OK 73104; e-mail: joan-walker@ouhsc.edu.

Disclosure: The researchers and Brawley report no relevant financial disclosures.