The grades of evidence (I-III) and levels of recommendation (A-C) are defined at the end of the "Major Recommendations" field.
The following recommendations are based on good and consistent scientific evidence (Level A):
- Women with BRCA1 or BRCA2 mutations should be offered risk-reducing salpingo-oophorectomy by age 40 years or when childbearing is complete.
- For a risk-reducing bilateral salpingo-oophorectomy, all tissue from the ovaries and fallopian tubes should be removed. Thorough visualization of the peritoneal surfaces with pelvic washings should be performed. Complete, serial sectioning of the ovaries and fallopian tubes is necessary, with microscopic examination for occult cancer.
- A genetic risk assessment is recommended for patients with a greater than an approximate 20–25% chance of having an inherited predisposition to breast cancer and ovarian cancer.
Levels of Evidence
I: Evidence obtained from at least one properly designed randomized controlled trial.
II-1: Evidence obtained from well-designed controlled trials without randomization.
II-2: Evidence obtained from well-designed cohort or case-control analytic studies, preferably from more than one center or research group.
II-3: Evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled experiments could also be regarded as this type of evidence.
III: Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees.
Grades of Recommendations
Level A: Recommendations are based on good and consistent scientific evidence.
Level B: Recommendations are based on limited or inconsistent scientific evidence.
Level C: Recommendations are based primarily on consensus and expert opinion.