countries using or considering the introduction of
mammographic screening for breast cancer. Most
importantly, it emphasizes the importance of concentrating
on programmes which educate women and health care
professionals so that breast cancer is diagnosed early and
women are competently treated.1 It is wise to heed what
Macpherson wrote in the BMJ in 2010 about the United
Kingdom National Health Service invitation to
mammographic screening programme (NHSBSP): "Since all
healthy women aged 50-70 are called for breast screening,
benefits (reduced mortality) ought to be unambiguous and
considerable and the risks of harm small".36
Most importantly for low- and middle-income countries, as
well as high-income countries, is the consideration of the
costs of mammographic screening, including both the costs of
the invitation to screen programme and the costs of the
unnecessary further investigations and treatment
consequent upon over-diagnosis. If early clinical diagnosis
and follow up diagnostic testing and treatment for breast
cancer are of a high standard in the country, then the
opportunity costs of introducing mammographic screening
need very careful consideration.
So is there an alternative to mammographic screening? In
high-income countries most breast cancer is not usually
diagnosed by screening mammography. For example, in
Australia only about a third of breast cancer is diagnosed by
mammographic screening.37 Most breast cancer in Australia
has been diagnosed early by women who have been educated
to be aware of the appearance and "feel" of their breasts:
"breast awareness".38 Some women perform specific breast
self-examination (BSE) regularly, but importantly in Australia
there is no financial barrier to women attending health care
professionals immediately they find any abnormality. Women
are also likely to undergo opportunistic clinical breast
examination (CBE) by their doctor on a regular basis. Since
1986, prior to the introduction of the "invitation to
screening" programme in Australia for women aged 50-69
years23, more than 80% of Australian women diagnosed with
breast cancer have had breast cancer that is confined to the
breast and the adjacent axilla17,39 and so meets the EBCTCG
definition of early breast cancer.16 Since 1995, 85% of breast
cancer in Australian women has been diagnosed early.40
Population-based treatment surveys have shown that
since 1995 the majority of Australian women diagnosed with
early breast cancer have been treated as advised by the
EBCTCG and breast cancer-specific mortality has been falling
in all age groups since then, well before the national
mammographic screening programme could have had an
impact on mortality.23 Many European countries have
experienced significant reductions in breast cancer-specific
mortality, which have also largely been attributed to
adjuvant therapy.41,42,43 Therefore, before contemplating
mammographic screening any country with a significant
burden of breast cancer should first ensure that women with
breast symptoms are educated to present to health care
professionals early and that breast cancer is diagnosed
promptly and competently and treated as described above.
There have been two RCTs testing BSE in Russia and China,
and BSE did not reduce breast cancer mortality in the
intervention groups, who were taught and practiced BSE, as
compared to the control groups who were only observed.44,45
Furthermore, results from several studies that suggested that
BSE screening greatly increases the number of benign lumps
detected, led the United States preventive services task force
to issue clear recommendations against teaching BSE, stating
that "For the teaching of BSE, there is moderate certainty
that the harms outweigh the benefits".46 However, it must be
noted that in both the China and Russian trials, there was
limited room for BSE screening to achieve a mortality
reduction since breast cancer awareness in the populations
was already high and the clinical stage at diagnosis was
relatively good.1 In the trial in Shanghai, China, 45% of the
control women were Stage I and only 1.5% of the BSE
intervention and 2.5% of the control women were Stage IV.
These trial results demonstrated that the specific process of
BSE does not carry benefit in those settings. The question
remains open for countries where a higher proportion of
cancers are diagnosed at late/advanced stages.
Evidence about the efficacy of population-based screening
for breast cancer with CBE is controversial. A Canadian RCT
of breast cancer screening evaluated the combination of
mammography and CBE versus CBE alone.47 This RCT
showed that there was no benefit in adding mammography to
CBE. Since the reduction in mortality in this Canadian trial
was the same in both arms and equivalent to that achieved in
some mammography-only RCT47, a reasonable conclusion
would be that CBE was equivalent to mammography as a
screening test in this Canadian setting. A RCT of CBE versus
observation is currently being conducted in Mumbai (India)
on 150,000 women aged 35-64 years. This study has now
entered its tenth year and more than 3 rounds of screening
have taken place. Early results show that the stage
distribution is significantly better in the screened group than
in the control groups. The principal objective of the trial, i.e.
demonstration of a reduction in mortality, will become
evident only after a further 5 to 8 years.48
A clinical down-staging programme conducted in Malaysia
covering a population of 1.1 million women, based on the
DISEASE-SPECIFIC CANCER CONTROL
CANCER CONTROL 2014 101