Routine cancer screening can save lives. But it also involves certain risks that need to be managed carefully.

A survey commissioned by The Malta Medical Journal opened a window on the state of breast screening in Malta. Many were surprised that 40 per cent of women do not go for breast screening even if the public health system offers a free screening service for women between the ages of 50 and 65. It was noted that “women’s understanding of the potential benefits has shown to be imperfect in this study”.

“Logistical barriers” have been partially blamed by the researchers for the low take-up of the screening service. Other reasons were “fear of the results” as well as physical discomfort and even pain experienced when undergoing the tests. Fear of being recalled for further screening is another reason that increases the anxiety of women who need to undergo these tests.

Logistical issues can be overcome with a little goodwill on the part of the public health service providers as well as their clients. What is more challenging is an understanding of “the potential, benefits, harms and shortcomings of breast screening, including over-diagnosis and overtreatment”. As Otis Webb Brawley, chief medical officer of the American Cancer Society states, “cancer screening is a double-edged sword”.

There is no doubt that advances in cancer screening now make it possible to find many tumours in their earliest stages. In such cases there is a much higher rate of successful treatment. In the US, results from randomised clinical trials show that screening mammography can help reduce the number of deaths from breast cancer among women ages 40 to 74. But medical science has its limits.

What we need is that scientists find better tests that are more specific, cheaper and more reliable in detecting the first signs of cancer. As Dr Brawley says, “what we really need is a 21st century definition of cancer so we can move away from 20th century screening and diagnosis using 1840s definition of cancer”.

According to most medical experts, today’s breast screening methods are the best we have ever had but theystill do not eliminate false-positive results that necessitate a high number of recalls for further testing, overdiagnosis and overtreatment as well as false-negative results, especially among younger women when mammograms appear normal even though breast cancer is present.

For people at high risk of cancer, the benefits of screening often outweigh the harms. For those not at risk, deciding on whether to undergo cancer screening should be done in consultation with the family doctor. Some medical professionals, like Susan Fisher, professor and chair of public health sciences at the University of Rochester, New York, advise that in groups at low risk, we may be creating more problems than benefits with early screening.

It is normal for most people, and not just women, to feel anxious before undergoing medical tests that could well indicate they have problem that needs attention. Education from the early stages of life about the realities of diseases, especially cancer, should not be delayed. Early screening has seen deaths from cancer falling significantly in the last few decades. Unfortunately, yes, routine screening can also cause serious damage.

There are limits to science. As Prof. Fisher rightly says, “the message for the public is that science is hard. As we get more and more information we get smarter about advice.”

In the meantime, the public health authorities should leave no stone unturned to make the screening service more client-friendly.