An unresolvable paradox
Public discourse on cancer is largely about new and better methods of treatment. These are often costly, and there is an ongoing debate on how the public health system should prioritise (4). Should we strive to provide the same sophisticated treatment that billionaires can buy at exclusive hospitals abroad (5), or should we lower expectations in the name of equity and socioeconomic realities? There are no easy answers, but progress continues: availability of advanced treatment is improving and more patients survive their cancer. Cancer research has contributed to a revolution in biomedical knowledge and technology, and the development of modern cancer treatment is a story of continuous scientific success.
Importantly however, this development also comprises a formidable paradox: According to the statistics, approximately one in three of us will get cancer during our lifetime (6), and because of modern medicine, most will survive. The problem is that having survived once increases the risk of getting cancer again. The reason familiar to most is that cells from the original tumour may have metastasised, to return elsewhere in the body. A lesser-known reason is that radio- and chemotherapy are themselves carcinogenic (7). What was lifesaving treatment in the first instance may thus be the cause of cancer and other diseases later in life. This information can be difficult to present to patients who have survived cancer and want to put those troubles behind them. Nevertheless, it is important that people know about this relationship. Late effects of cancer treatment can often be reduced by preventive measures, and cancer survivors need special follow-up (8).
Although important, neither metastases nor cancer-inducing cancer treatment is the main reason why cancer is on the rise in the population. By far the most important cause of the increase in cancer cases is simply that we are living longer (6, 9). Cancer may affect anyone, and there are several underlying causes. Some forms are clearly hereditary, while others are primarily due to environmental factors. Yet there is no risk factor more important than advanced age. The risk increases especially after the age of 50 and after the age of 80 most people have cancer cells in their body. It is only a matter of how carefully you look (10). The chances are that you will die with rather than from the cancer, but the trend is clear: as we grow older, our cells become increasingly unruly.
The better we become at treating cancer and other diseases, the longer we live and the more cancer cases there will be in the population. The great cancer epidemic is therefore not a problem modern medicine is about to solve – it is a problem we are about to create. The idea that the solution to cancer awaits around the next corner, as some kind of ingenious medical discovery, is therefore misleading and should be discarded once and for all (11). We can cure individual diseases and extend the average life expectancy, but we cannot treat ourselves out of the cancer epidemic.