Please note: In 2003, the CTF updated its Grades of Recommendations to include an "I Recommendation" for situations where insufficient evidence exists to allow a recommendation to be made. (Formerly, these situations were captured under a "C Recommendation".) This change is not retroactive, and all "C Recommendations" made prior to 2003 have not been reevaluated in light of the new "I" recommendation grade. For a discussion of these recommendation grades, please link to the 2003 article in the Canadian Medical Association Journal here.
These recommendations were finalized by the Task Force in August 1999
| MANEUVER | EFFECTIVENESS | LEVEL OF EVIDENCE <REF> | RECOMMENDATION |
| Mammography every 12-18 months* | Relative risk reduction of 18-45% for breast cancer mortality at 10 years was shown in 2 trials and one meta-analysis; no benefit was shown in 6 other trials† | RCTs <2,3,5,6,15-42> (I)§ | Current evidence does not support the recommendation that screening mammography be included in or excluded from the periodic health examination of women aged 40-49 at average risk of breast cancer (C)¶ |
Note: RCT = randomized controlled trial. *Comparison of RCT results suggests that, if done, frequent screening may be required. The value of adding clinical breast examination to mammography is unclear. †The only trial that enrolled Canadian women failed to show an effect of screening mammography, possibly because of low power. §Six of the 7 RCTs assessed mammography for this age group as a subgroup analysis. ¶This represents a change from the 1994 grade D recommendation. Level I evidence is available, but some results conflict and not all relevant issues are resolved. Upon reaching the age of 40, Canadian women should be informed of the potential benefits and risks of screening mammography and assisting in deciding at what age they wish to initiate it.
Link to Full Text of this review
Link to Structured Abstract of this review
Link to Selected References list of this review
Link to 2001 Update: Breast Self-Examination to Screen for Breast Cancer
Link to 1999 Update: Follow-up after breast cancer
Link to 1998 rewording of recommendation for screening women aged 50-59 for breast cancer
Link to 1994 Chapter: Screening for breast cancer
Reprinted in modified format by the Canadian
Task Force on Preventive Health Care
with permission.
Original Copyright
© 1999 Minister of Supply and Services Canada.
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Last modified: February 20, 2001.
