***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVES : To estimate women 's expectations of the accuracy of screening mammography and to explore attitudes towards compensation for missed cancers . DESIGN : Cross sectional survey ( by telephone ) . SETTING : Australia ; population -based survey conducted in April 1996 . PARTICIPANTS : R and om sample of women aged 30 - 69 years . A total of 2935 women completed the Breast Health Survey ( adjusted response rate 65 % ) . A r and om sample of 115 completed this sub-survey on perceived sensitivity of mammographic screening and compensation for missed cancers . RESULTS : About one third of women ( 32.2 % , 95 % CI 23.7 , 40.7 ) had an unrealistically high expectation of the sensitivity of screening mammography  , reporting it to be 95 % or higher . Approximately 40 % of the women ( 43.5 % , 95 % CI 34.4 , 52.6 ) thought that screening mammography should pick up all cancers ( should have a sensitivity of 100 % ) . Just under half the women ( 45.2 % , 95 % CI 36.1 , 54.3 ) said financial compensation should be awarded for a cancer missed by screening mammography  even if the cancer was missed as a consequence of the small failure rate of the test . Younger women living in metropolitan areas and women who had realistic expectations of the accuracy of the tests were more likely to favour financial compensation . CONCLUSION : Unrealistically high expectations of the sensitivity of screening mammography  were common in this group of women . Many women favoured financial compensation for missed cancers even if the cancer was missed solely because of the failure rate of the test . Public education is required to inform women of the limited sensitivity of breast cancer tests but this may not reduce cl aims for financial compensation when cancers are missed Results from the r and omized trial conducted by the Health Insurance Plan ( HIP ) to determine the efficacy of breast cancer screening with mammography and palpation are reported for longer periods than previously available . By the end of 10 years after entry , the study group 's  mortality due to breast cancer was about 30 % below the control group 's . Arithmetic gains due to screening were maintained through year 14 ; relative gains declined . With increases in the period of follow-up , cumulative survival rates among cases detected by mammography alone ( palpation negative during screening ) , decreased more rapidly than rates among other subgroups , but survival rates for mammography cases remained relatively high . Study women aged 40 - 49 years at entry began to show lower breast cancer mortality than those in the control group as duration of follow-up increased . Reservations are advanced about the acceptance of this finding as evidence of the efficacy of screening under age 50 under the conditions of the HIP study . The reservations are based on the observation that the decrease of mortality among the study group aged 45 - 49 at entry is concentrated entirely among cases diagnosed after they reached 50 years of age Edinburgh was selected as one of the centres in the UK Seven-year Trial of  Breast Screening of women aged 45 - 65 which began in 1979 . Subsequently , our study was extended to a r and omised trial with its own control population within the city . Half the practice s were r and omly allocated for screening , giving a cluster sampling of women . The total number in the trial is 65,000 . Women with previously diagnosed breast cancer are excluded . Women allocated for screening are invited to the clinic and screened according to the procedures specified in the U.K. protocol , having clinical examination every year and mammography on alternate years . The two modalities of screening are assessed independently and the role of nurses is being evaluated . Breast cancer incidence is monitored by pathology register and the local cancer registry office and deaths from the General Register office . Long-term follow-up will be obtained through flagging at NHS Central Register . To determine the value of screening , st and ard statistical methods will be used to compare breast cancer mortality rates in the whole of the screening population with that of the controls . This trial has a power of 83 % of detecting a reduction in mortality of 35 % after 7 years of follow-up and a power of 95 % of detecting a similar reduction at 10 years ( alpha = 0.05 , one-sided test ) Background : False-positive recall is a recognized disadvantage of mammographic breast screening , and the rate of such recalls may be higher in younger women , potentially limiting the value of screening below age 50 . Methods : Attendance and screening outcome data for 53,884 women in the intervention arm of the U.K. Age trial were analyzed to report observed false-positive recall rates during 13 years of trial fieldwork . The Age trial was a r and omized controlled trial of the effect of mammographic screening from age 40 on breast cancer mortality , conducted in 23 National Health Service screening centers between 1991 and 2004 . Women r and omized to the intervention arm were offered annual invitation to mammography from age 40 or 41 to age 48 . Results : Overall , 7,893 women ( 14.6 % of women the intervention arm and 18.1 % of women attending at least one routine screen ) experienced one or more false-positive screen during the trial . The rates of false-positive mammography at first and subsequent routine screens were 4.9 % and 3.2 % , respectively . The cumulative false-positive rate over seven screens was 20.5 % . Eighty-nine percent of women who had a false-positive recall at their previous screen attended their next invitation to routine screening . Conclusions : The rates of false-positive recall in the Age trial were comparable with the national screening program ; however , the positive predictive value of referral was lower . Experiencing a false-positive screen did not seem to lessen the likelihood of re-attendance in the trial . Impact : The question of greatly increased false-positive rates in this age group and of their compromising re-attendance is refuted by the findings of this study . Cancer Epidemiol Biomarkers Prev ; 19(11 ) ; 2758–64 . © 2010 AACR Debate continues over the effectiveness of screening by mammography in women below age 50 . We report here on results of screening in the first 10 years of a r and omised trial to study the effect on breast cancer mortality of  invitation to annual mammography  from age 40 to 41 compared to first invitation to the 3-yearly  UK national programme  at age 50–52 . The trial is taking place in 23 NHS breast screening centres . Between 1991 and 1997 , 160 921 women were r and omised in the ratio 1 : 2 to intervention and control arms . Screening is by two views at first screen and single view subsequently ; data on screening up to and including round five are now complete . Uptake of invitation to screening is between 68 and 70 % at all but the latest screening rounds . Rates of referral for assessment are 4.6 % at first screen and 3.4 % at subsequent screens . Invasive cancer detection rates are 0.09 % at first screen , and similar at rescreens until the sixth and later screens . There is little evidence of regular mammography in the trial control arm . The setting of this trial within the NHS breast screening programme should ensure applicability of results to a national programme OBJECTIVE To establish the extent of women 's knowledge of mammographic screening , particularly in relation to the national screening program , BreastScreen Australia , and to estimate the proportion of women who are participating in screening both within and outside BreastScreen Australia . DESIGN AND SETTING Vali date d prospect i ve telephone survey of women aged 30 - 69 years selected at r and om from across Australia . PARTICIPANTS 2935 women with no previous breast cancer diagnosis . RESULTS The adjusted response rate was 64 % . Almost 90 % of women had heard of the national program ; only 1 % correctly stated that screening is for asymptomatic women . 60 % correctly identified the current recommended age of starting screening is about 50 years of age ; 26 % thought screening should begin at about 40 years of age . Approximately 60 % correctly reported that the recommended screening interval is every two years ; 27 % thought screening should be done annually . 55 % reported ever having had a mammogram , and 37 % reported having had at least one screening mammogram . Among women in the target age group ( 50 - 69 years ) about 70 % reported ever having had a screening mammogram , and about 50 % reported having had a screening mammogram within the national program in the last two years . Among women aged 40 - 49 years , 29 % reported ever having had a screening mammogram , and 22 % reported having been screened in the last two years . CONCLUSIONS Awareness of the national screening program is high , but some women do not know the purpose of screening , the target age group and the recommended screening interval . Compliance with screening is good among women in the target age group ; many women in their 40s are also participating in screening The results of the Swedish two-county trial of mammographic screening for breast cancer are presented , up date d to December 31 , 1990 , which is an average of 10.8 years follow-up per person . The main result of the trial in terms of breast cancer mortality remained the same : compared with the control group , the group invited to screening had a relative breast cancer mortality of 0.70 ( P = 0.0002 ) with 95 % confidence interval ( 0.58 , 0.85 ) . Analysis of survival showed that relative to the control group , the cancers detected at prevalence screen , incidence screens , and in the interval between screens had a good prognosis , whereas cancers detected in those who had refused screening had a very poor prognosis . When adjusted for tumor size , lymph node status , and tumor grade ( differentiation ) , the better survival associated with incidence screen and interval detection was largely accounted for , indicating that the benefit of incidence screening is largely achieved through the effect of screening on the three prognostic variables , notably size of the tumor . Results indicate that to achieve a substantial mortality reduction , 50 % of screen-detected invasive cancers should be less than 15 mm in diameter , at least 30 % of screen-detected grade 3 tumors should be less than 15 mm , and at least 70 % of screen-detected tumors should not have lymph node metastases . The percentage of grade 3 tumors of a given size should be the same in screen-detected cancers as in clinical ly detected , and breast cancer prevalence at first screen should be at least three times the expected incidence rate in the absence of screening . This should be achieved without the recall rate for further examination exceeding 9 % , and procedures including further imaging techniques and fine needle aspiration or core biopsy should be used before resorting to surgical biopsy . These aims can be achieved in specialist screening centers if particular attention is paid to re sources for screening and diagnostic evaluation , specialist training of clinical and technologic screening staff , and ongoing monitoring of mammographic quality , recall rates , and the attributes of the tumors detected BACKGROUND : It has recently been suggested that all-cause mortality is a more appropriate end point than disease specific mortality in cancer screening trials , and that disease specific mortality is biased in favour of screening . This suggestion is based partly on supposed inconsistencies between all-cause mortality results and disease specific results in cancer screening trials , and alleged increases in deaths from causes other than breast cancer among breast cancer cases diagnosed among women invited to screening . METHODS : We used data from the Swedish Two-County Trial of mammographic screening for breast cancer , in which 77 080 women were r and omised to an invitation to screening and 55 985 to no invitation .  We estimated relative risks ( RRs ) ( invited v control ) of death from breast cancer , death from other causes within the breast cancer cases , and death from all causes within the breast cancer cases . RRs were adjusted for age and took account of the longer follow up of breast cancer cases in the invited group due to lead time . RESULTS : There was a significant 31 % reduction in breast cancer mortality in the invited group ( RR 0.69 , 95 % confidence interval ( CI ) 0.58–0.80 ; p<0.001 ) . There was no significant increase in deaths from other causes among breast cancer cases in the invited group ( RR 1.12 , 95 % CI 0.96–1.31 ; p=0.14 ) . A significant 19 % reduction in deaths from all causes was observed among breast cancer cases in the group invited to screening ( RR 0.81 , 95 % CI 0.72–0.90 ; p<0.001 ) . A more conservative estimation gave a significant 13 % reduction ( RR 0.87 , 95 % CI 0.78–0.97 ; p=0.01 ) . These findings are consistent with the magnitude of the reduction in breast cancer mortality . CONCLUSIONS : Invitation to screening was associated with a reduction in deaths from all causes among breast cancer cases , consistent with high participation rates in screening . There is no significant evidence of bias in cause of death classification in the Two-County Trial , and as breast cancer mortality is the targeted clinical outcome in breast cancer screening , it is the appropriate end point in a breast cancer screening trial . All-cause mortality is a poor and inefficient surrogate for breast cancer mortality BACKGROUND The cumulative risk of a false-positive mammogram can be substantial . We studied which variables affect the chance of a false-positive mammogram and estimated cumulative risks over nine sequential mammograms . METHODS We used medical records of 2227 r and omly selected women who were 40 - 69 years of age on July 1 , 1983 , and had at least one screening mammogram .  We used a Bayesian 
    Output:
    
We found that breast cancer mortality was an unreliable outcome that was biased in favour of screening , mainly because of differential misclassification of cause of death .
Screening is likely to reduce breast cancer mortality .
It is thus not clear whether screening does more good than harm .