Research published recently suggests that the cost of treating cancer in the US has doubled over the last 20 years. This surprised me – I would have expected a much greater increase.

The research finds that the increased costs arise mainly from an increase in cancer cases, rather than the per-case cost. The increase in the number of cases is not a surprise. Not only are people living longer – and the risk of developing most cancers increases exponentially with age – but the risks of dying from circulatory diseases has dropped sharply since the 1970s. This has meant that, for example, many people who would have died of heart attacks have survived to develop cancer instead.

This is particularly interesting in relation to smoking. If you stop smoking, your risk of dying from a circulatory disease drops very quickly. However, the damage done by smoking at a cellular level can take years to emerge, so the risk of developing cancer falls much more slowly.

However, new cancer treatments are being developed all the time, with an increasing focus on these treatments – why has this not led to a large increase in costs?

One reason is a change in emphasis by insurers in the US towards outpatient care. This is often better for patients, but it is also cheaper for the insurance companies. However, there is also a more fundamental reason why the cost of treatment has not risen as quickly as might be expected. Although more research is being carried out into cancer treatments, the number of patients has grown. This means that the cost of drugs on a per patient basis does not need to rise as quickly as the cost of research and development rises in aggregate. This is the silver lining around the cloud that is the increasing incidence of age-related cancer.