Screening for Ovarian Cancer: US Preventive Services Task Force Reaffirmation Recommendation Statement
US Preventive Services Task Force
This guideline1 focuses on screening for ovarian cancer in asymptomatic women. It reaffirms the 2004 statement of the U.S. Preventive Services Task Force (USPSTF)2, which recommended against screening with transvaginal ultrasonography or single-threshold serum CA-125 testing. At that time, the rationale for the recommendation was that while there was evidence that screening can detect ovarian cancer at an early stage, no trials were found that examined the effect of screening on mortality. Further, the harms of screening were high, thus outweighing any small potential mortality benefit. Since the 2004 recommendation, new evidence from a randomized controlled trial (RCT) has demonstrated that screening does not reduce mortality due to ovarian cancer.Ovarian cancer represents only 2.9% of annual new cancer diagnoses (excluding skin cancer) among Canadian women but is associated with poor 5-year survival (42%)3. Because ovarian cancer is rare in the general population, tests aimed at early detection (using transvaginal ultrasonography and CA-125 testing alone or in combination) are associated with a high false-positive rate: for every 100 women with a positive screening result, only 1 has ovarian cancer4. False-positive test results may lead to unnecessary surgery and surgical complications. Although some practitioners perform regular bimanual pelvic examination to screen for ovarian cancer, the USPSTF did not identify any RCTs that evaluated the effectiveness of this intervention on screening.
This guideline was developed in the United States by a broad range of experts and is targeted toward clinicians.
RELEVANCE TO CTFPHC MANDATE
All sections of this guideline are applicable to the CTFPHC mandate of prevention in primary care.
The target population for this recommendation is asymptomatic women without known genetic mutations that would increase the risk for ovarian cancer.
EVIDENCE REVIEW METHODS
The USPSTF last reviewed the evidence in 2008, at which point there was no new evidence addressing the benefit of screening. Therefore, the current search4 included literature published between 15 October, 2007, and 26 July, 2011, to identify “substantial evidence” (i.e., RCTs) on screening for ovarian cancer in asymptomatic women that became available since the USPSTF’s previously unpublished 2008 review. The following databases were searched: PubMed, MEDLINE and the Cochrane Central Register of Controlled Trials. Titles and abstracts of 848 articles were reviewed, the full text of 30 articles was reviewed, and the final recommendation was based on evidence from 4 articles arising from 3 RCTs.
The USPSTF assigns 1 of 5 letter grades to each recommendation: A, B, C, D, or I5. These grades are based largely on the level of certainty and magnitude of the net benefit associated with providing the service. For more information on the grading scheme, see Table 2 and Table 3.
The CTFPHC assessed the methodological quality of the guideline using the Appraisal of Guidelines Research & Evaluation (AGREE II) criteria (Table 1).This guideline scored above 60% on the domains of Scope and Purpose, Rigour of Development, and Editorial Independence; therefore, the CTFPHC has classified it as a high-quality guideline. Concordance among reviewers, as measured through standard deviation of AGREE II scores, was high (SD < 1.5) for all domains except Applicability.
|AGREE II domain||Domain score||Standard deviation|
|Scope and purpose||98%||0.3|
|Rigour of development||90%||1.0|
|Clarity of development||97%||0.3|