Breast screening, is it justifiable?

The influential medical journal, The Lancet, way back in 2001 reported that Gøtzsche and Olsen had conducted a systematic review of randomised trials of screening mammography. These concluded that "screening for breast cancer with mammography is unjustified".

Reporting this 'cruel' finding had created a storm of debate and criticism in the international media and even in medical journals. These investigators, working at the respected Nordic Cochrane Centre, found that the best trials did not provide evidence of a reduction in either total or breast cancer mortality. After seven years, their claim has not been disproved; nor is there new evidence that suggets mammographic breast screening on its own will reduce mortality from breast cancer.

After 10 years of national breast screening in England, the death rate from breast cancer remained almost the same from 1971-97 (Social Trends, 29. 1999, p. 321). Yet the controversy is still on and health policymakers are still trying to justify their decisions.

There are other simple and cost-effective ways to detect breast cancer. These include more awareness and education, self- examination and selective screening (rather than mass screening). It has been shown that clinical breast examination is more likely to detect cancers that are potentially lethal. Mammography is complex, expensive, and only partially effective. Also, mammography does detect some cancers 'early', but many of these are not potentially lethal and their detection causes needless anxiety.

Needless to say, to adopt the best policy one needs to review the studies done abroad on a very large scale and consult local experts as well, including clinicians, public health experts and epidemiologists. Was this procedure followed before the screening programme was launched as a pre-election promise?

The information currently provided to healthy women, exhorting them to attend screening because diagnosing cancer early could save their life, is now less than honest and has not kept pace with the unexpected beneficial spin-offs and pitfalls of mammographic screening.

Candidates for screening should be given honest, balanced information stating the numbers needed to screen to affect mortality and not frightened by irrelevant incidence figures or led to believe that earlier is better. Pressure from the media and women's advocacy groups tend to encourage an irrationally defensive attitude to mammographic screening.

At this point in time we need to avoid an adversarial mode as this tends to prevent a balanced assessment of the latest evidence or a proper analysis of cost- effectiveness.

But, is this another fait accompli? Both political parties have already spilt the beans about a national breast screening programme, thus raising the expectations of the public without informing them of the public health benefits if any, or the associated risks, such as false positive and false negative reports.

Were the costs/benefits to the individual, medical services and community considered? With our financial constraints, money spent on the screening programme could be spent on alternative projects, such as a more comprehensive primary care service. A national screening programme requires much more than just a modern mammogram machine - trained personnel, facilities, quality control, call-up and re-call procedures, collection of relevant data, etc. Do we have these resources?