Studies Included	Comments	Conclusions
All RCTs*	Canadian NBSS-1 was the only RCT that specifically addressed issue in 40- to 49-year-old women. Mortality reduction smaller in younger than older women. Interval between initiation of screening and showing of benefit longer in younger women.	Effectiveness of screening asymptomatic 40- to 49-year-old women remains unresolved. UK Age Trial to assess efficacy of annual screening of women aged 40 and 41 years.

^*RCT indicates randomized controlled trial