Prevention Scottish Government has recently launched a consultation on its Cancer Strategy, which makes it a good time to reflect on what is likely to have the greatest impact on Cancer Care in the future. There is no doubt that we shall see significant advances in treatment.

Further developments in minimal access (keyhole) and robotic surgery will make it increasingly possible to carry out major complex surgery with less discomfort for the patient, and more focus on the quality of surgery will reduce the rate of complications.

It is now clear that cancer is not just one disease, but a spectrum of diseases, and our improving understanding of the biology of cancer will allow drug treatment to be tailored to individual patients, reducing side effects and increasing efficacy.

However, in many types of cancer, if not all, treatment is much more effective and requires less intervention when diagnosis is achieved at an early stage.

In my view, therefore, the most important areas to concentrate on are early detection and prevention. At the present time we have national screening programmes for cervical, breast and bowel cancer, which, though not perfect, have significant impact on the numbers of people in Scotland who die as a result of these diseases.

One of the main reasons that these programmes don’t reach their full potential is that a substantial proportion of people who are invited choose not to take the tests that are offered.

This choice can be made for very good and rational reasons, but often it can be made because of unwarranted fear, disgust (particularly with the “poo” test for bowel cancer), or inconvenience. Increasing acceptance of screening invitations, without any attempt at coercion, will undoubtedly pay dividends.

Of course, increasing uptake of screening will put more pressure on diagnostic services, which were hit hard by the Covid 19 pandemic, and it is to be hoped that provision of speedy and accurate diagnosis will be at the heart of any new Cancer Strategy.

One question that is often asked is “why do we only offer screening for three types of cancer?” The fact is that screening can cause harm as well as good. For example, some people have false positive test results and undergo unnecessary further tests and even treatment. Also, screening inevitably causes anxiety while waiting for results, and since only a very small number of people undergoing screening will have cancer, a lot of this anxiety is unnecessary.

It is therefore very important that research is done that proves conclusively that screening delivers more good than harm, and for cervical, breast and bowel cancer, we know this to be the case.

We also know that by scanning the lungs of people who are current or past heavy smokers the number that die of lung cancer can be significantly reduced, and serious consideration is now being given to a lung cancer screening programme.

One of the major challenges with lung cancer screening is how to identify and invite everyone who would benefit and there is ongoing work on this led by the University of Edinburgh.

Of course, there are many other types of cancer, but we still do not know how best to detect them early, or even if early detection helps.

There has been research into both prostate and ovarian cancer, which has shown that screening doesn’t help, and indeed, prostate cancer screening using the PSA blood test finds lots of men with a form of cancer that is very unlikely to cause death so that many men undergo treatment with severe side effects to no good purpose.

This doesn’t mean that early detection is of no value, it just means that we still don’t have tests that are sufficiently accurate to allow effective screening in these cancers.

This is an area that is likely to change in the near future with research that is underway in Scotland and elsewhere.

Although better early detection through screening is an important goal for the future of cancer care, a more pressing and difficult problem is how to prevent cancer from occurring in the first place.

There are specific measures that can be put in place, and a very good example is vaccination against the human papilloma virus (HPV) which causes cervical cancer. This is now offered to all 12-year-old children and will have a huge impact; it will certainly reduce the need for screening for cervical cancer and will also protect against other cancers caused by the virus.

However, the main approach to cancer prevention is more simple and more complex at the same time. Simple, because we know that 40% of cancers are preventable by lifestyle change. Complex, because changing our lifestyle in the face of pressures that encourage unhealthy behaviour is so difficult.

The main culprits are smoking, being overweight, dietary factors, taking too little exercise, drinking too much alcohol and exposing our bodies to too much sunlight. All of these increase our risk of cancer and yet there are few of us who don’t engage in any of these risky activities.

Why is it so difficult to stop doing these things? It is difficult since they are all associated with enjoyment, and largely because we are persuaded by commercial organisations that they are enjoyable.

Especially in Scotland, we have made great strides in smoking with bans on advertising and smoking in public places leading to reductions in smoking rates and the numbers of people with lung cancer.

There is still a lot to do here, however, hence the interest in lung cancer screening, and it is really important to continue to invest in reducing smoking rates further with a view to eradicating the habit completely.

When it comes to being overweight, and two-thirds of adults in Scotland are, this is harder to tackle since we all have to eat and drink (although not snack foods, confectionary and alcohol!).

It is within the power of the retail and food and drinks industries to ensure that promotion of unhealthy food and drink is avoided, and yet we are constantly exposed to fatty, sugary products that are hard to resist. Sadly, the only effective approach appears to be legislation, and all we have currently is minimum pricing on alcohol and a soft drinks industry levy on sugary drinks.

Action on cancer prevention (and, incidentally, prevention of diabetes, heart disease and many other causes of premature death) must be a priority for the future, and this action needs a robust approach with strong Government leadership.

The right approach to prevention and delivering the right treatment at the right time are the keys to success for any Cancer Strategy.

Bob Steele is professor of surgery at Dundee University; chair of the UK National Screening Committee (2015-2022); clinical director of the Scottish Bowel Screening Programme; and chair of the Board of Trustees at the Scottish Cancer Foundation