Table J3 - Screening women 50

A Evidence based guidelines - the evidence base for mammographic screening of women between the ages of 50 and 64 years

Evidence Table J3

Mammographic screening of women 50 - 64 years old

A	Clinical Problem	Screening women 50 - 64 years old
A1	Ref No. in MBUR4 (if any)	J4
A2	Section in MBUR4	Breast disease
B	Search strategy: databases used; period; MeSH headings; other key words.	Medline 1966-2001, EMBASE 1988-2001, handsearch selected journals, diagnostic imaging, mamography, breast neoplasm, mass screening, population screening
C	Search results: no. found; no. used.	564, used 11
D	Reference numbers of cited references in attached master list.	J3 1-11
E	Summarised results from each of the cited references	There have been 8 RCTs and 5 case control studies of screening mammography in this age group. Miller et al showed increased mortality in the mammography group, the methodology of this trial has been criticised. All other studies showed a reduction in mortality in the women offered screening of between 20 and 50% for RCTs ( average 24%) and averaged as 56% for case control studies. Demmisie et al explain the larger reductions in case control studies by the non compliance with screening of some women in the study groups and the contamination of the control groups by mammography, reducing the effect of screening in these studies. Tabar et al have also reported the effect of subsequent introduction of service screening in the Two counties with persisting reduction in mortality of 48%.
F	Statement (= the conclusion drawn from E)	There is extremely strong evidence for the benefit of regular screening on reducing breast cancer mortality in this age group both in the setting of trials and service screening
G	Evidence level of F classified I - IV	1
H	Investigation	Mammography
I	Recommendation *	1 - Indicated
J	Grade of Recommendation A - C	A
K	Comment (if any) to go in booklet version of MBUR5	Women age 50-64 are invited for screening 3 yearly in the UK under the auspices of the NHSBSP
L	Any other comments on this problem (e.g. caveats; suggestions for research or systematic review; cost or opportunity cost; users' views.	Ros Given-Wilson

Comments: Despite some critics of screening, the balance of literature strongly supports the screening of women between the age of 50 and 64 years. Evidence about the screening interval suggests more frequent screening should reduce interval cancers. The Frequency Trial is due to report in 2002.

References: -

Ref ID	Author; Year; Country; Grade (I-IV).	Aims	Patient population	Study design*	Results
J3 1	Forrest P, 1986, UK, 1	Report reviewing evidence for and feasiblity of a national breast cancer screening programme	Women in 2 RCTs and 2 case control studies	Review of studies	Deaths from breast cancer in women age 50-64 who are offered screening by mammography can be reduced by a third or more
J3 2	Shapiro S, 1982, USA,1	RCT in Health Insurance plan of clinical examination and mammography	62,000 women in study and control groups age 40-64	RCT	10 years after randomisation 30% reduction mortality in study group and 18 years after residual 23 % reduction
J3 3	Tabar L, 1985, Sweden 1	RCT of screening mammography	163,000 women in study and control groups age 40 and over	RCT	In first 7 years 31% reduction in breast cancer mortality in study group
J3 4	Andersson I,1988, Sweden,1	RCT of screening mammography	22,283 women age over 45 in study and control groups	RCT	Women over 55 showed a 20% reduction in breast cancer mortality
J3 5	Frisell J, 1997, Sweden, 1	RCT of screening mammography	40,318 women age 40-64 in study and control groups	RCT	In women age 50-64 there was a 38% reduction in mortality
J3 6	Anon, 1999, UK, 1	Comparison of BC mortality in 2 areas offered screening, 2 offered breast SE, and 4 controls	300,000 women in 8 HA age 45-64	Non Randomised CT	35% reduction in mortality on 16 years of follow up of patients age 45-46 at entry, 27% reduction in mortality overall cohort of women age 45-64 compared control group
J3 7	Alexander FE, 1999, UK 1	RCT of screening mammography within UKTEDBC	54,654 women age45-64 in study and control groups	RCT	After adjustment for differing socio economic status mortality reduction in the screened group was 21%
J3 8	Miller AB, 2000, Canada, 1	RCT of mammographic screening and PE versus PE	39,405 women age 50-59	RCT	At 13 years of follow up mortality in mammography group RR was 1.02 compared to PE group
J3 9	Verbeek ALM, 1984, Netherlands,2	Case control study of mammographic screening	30,000 women over 35 screened and controls	Case control	The risk of a screened woman dying of breast cancer compared to a control was 0.48
J3 10	Demmisie K,1998, USA, 2	Comparison of results of RCTs and case control studies of mammographic screening	Women in 8 RCTs and 5 case control studies of screening age 40-74	Review	Summarised RR in RCTs was 0.76 and in case control studies was 0.44 for mammography groups, difference explicable on basis of non compliance in study groups and contamination of control groups of RCTs
J3 11	Tabar L, 2001, Sweden, 1	Comparison of effects on BC mortality of the STC of screening and then of the introduction of organised service screening	6807 women diagnosed with BC iin a 29 year period in 2 counties	RCT and review of mortality after RCT	Mortality in women who attended for screening during STC reduced 63%, reduction in those invited reduced 50%, mortality reduction of 48% was maintained with service screening