world cancer report - iarc

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Japan, Miyagi
1960 19701980 1990 2000
Fig. 4.32 Trends in breast cancer incidence. D.M. Parkin et al. (2001) Eur J Cancer 37, suppl. 8: S4-66.
specified age group. As of 1995, at least
22 countries had established national,
sub-national or pilot population breast
cancer screening programmes [8]. The
specification of an eligible age range, and
the “repeat interval”, are matters for
national (or other authoritative) policy and
vary accordingly. All programmes screen
women by age 50 and repeat intervals are
between one and three years.
Establishment of the programmes depends
on national or other health policy.
There is considerable variation between
screening programmes in relation to factors
such as sociopolitical status of the
screened population, public health priorities
and funding sources. Implementation
of population-based screening necessitates
the provision of technical resources
T
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Puerto Rico
1960 19701980 1990 2000
Fig. 4.33 Mammograms (2 views) from a patient displaying evidence of breast
cancer. T = tumour.
T
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UK, South Thames
1960 19701980 1990 2000
100
and the availability of trained personnel,
together with a media campaign to publicize
the service. The latter may be directed
in part toward particular groups,
including the elderly and/or women of low
socioeconomic status, or who are members
of minorities, since such groups are
known to undergo mammography less frequently
than the general population [9].
The evaluation of individual mammograms
requires appropriate expertise and quality
assurance standardization. Independent
double reading of mammograms is recommended,
but not carried out in all screening
programmes [8,10]. It is also essential
to provide for adequate “follow-up” procedures
in respect of initial mammographic
results not categorized as satisfying the
criteria for normality. Follow-up necessi-
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25
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1
Australia, NSW
1960 19701980 1990 2000
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Denmark
1960 19701980 1990 2000
tates contact with the individuals concerned,
repeat and more comprehensive
mammography, physical examination,
ultrasonography and potentially biopsy.
Cancers diagnosed after a negative mammogram
are known as “interval” cancers.
Mammographic breast density appears to
be a major risk factor for interval cancer,
worst risk being associated with extremely
dense breasts [11]. Clinical examination
and self-examination, whilst not proven to
show a benefit in terms of reduction in
breast cancer mortality, may aid in the
detection of interval cancers, and are
being evaluated for screening in countries
that cannot afford mammography programmes.
The International Breast Cancer
Screening Network provides a basis for
international collaborative effort designed
Fig. 4.34 The evaluation of mammograms requires appropriate expertise and
standardization.
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USA
White
Black
1960 19701980 1990 2000
Screening for breast cancer
157