Let's be clear about cancer and miracles. Until the middle of the 20th century, a cancer diagnosis was in most cases a death sentence. Today, more than 60 per cent of Australians who are told they have a potentially terminal cancer are alive five years later. Thousands of patients each year are treated successfully.
Miraculous as it sounds, this is easily explained.
Decades of research into treatment and early detection of cancer, being guided by scientific evidence, conducting clinical trials and continually adapting clinical practice accordingly have enabled medical professionals to achieve treatment outcomes that may have seemed miraculous to previous generations.
We also know that about one-third of cancer deaths in Australia are linked to behavioural risk factors such as smoking, poor nutrition and physical inactivity, exposure to ultraviolet radiation and alcohol consumption.
Scientific research has the potential to expand the evidence base on the causes of other cancers, enabling us to predict, detect and treat cancer more effectively. Genetic technology will be one of the keys to reducing cancer burden.
So the miracle of cancer control is science and the capacity of human beings to work together and ensure that clinical practice is based on the best available scientific evidence.
Interest in religious medical miracles has been revived by media coverage of this weekend's canonisation of Mary MacKillop as a Catholic saint, which is based in part on claims that she mediated, decades after her death, to help cure two cancer patients who were otherwise incurable.
Although miracles have been claimed for millennia, today such reports are easier to disprove and therefore harder to accept. In the absence of a scientific explanation for reported miracle cures, an interpretation is based on deeply personal religious beliefs, held by some but dismissed by others in a pluralistic society.
Spontaneous remission from an apparently terminal cancer is a rare but documented and unexplained phenomenon.
As the science of oncology evolves, such cases may be easier to explain. But there will always be limits to our knowledge.
The message for cancer patients is that they should seek the benefits of evidence-based medicine rather than hope for a miracle. However, evidence also shows there is no harm in prayer, provided it's not done as an alternative to the types of conventional treatments that have profoundly improved overall cancer survival rates in recent years.
Patients who have faith could choose to add prayer to conventional treatment, as the two are not mutually exclusive.
The international Cochrane Collaboration, which systematically reviews all the evidence from studies on medical topics, has reviewed the intercessory prayer literature three times, most recently last year.
It analysed studies in several different diseases, finding evidence to be equivocal, so it did not support a recommendation in favour of or against the use of intercessory prayer. This is all the more reason for people diagnosed with cancer to seek conventional treatment, where the evidence of benefit is clear even though we cannot successfully treat all cases, often depending on the type of cancer and how early it has been detected.
Some studies have shown that prayer can improve an individual patient's wellbeing. Before working at Cancer Council Australia, as a medical oncologist in Adelaide I was involved in a study designed to contribute to the evidence base on prayer in relation to wellbeing in cancer patients.
The study -- developed with input from a theologian and an atheist -- did not set out to investigate any clinical benefit of prayer but to measure changes in a scale of spiritual wellbeing. It should be noted here that spirituality can be a characteristic of all people, independent of whether it is expressed through any formal religious affiliation or belief.
In the study, patients were randomly assigned to two groups: one group was prayed for, without members' knowledge -- to rule out any effect of suggestion -- by a local Christian church; members of the other group were not.
There was a small but significant improvement in spiritual wellbeing in the patients who had been prayed for, as reported in terms of a sense of peace, faith and emotional wellbeing. The study did not and could not address why this occurred. It clearly did not suggest prayer could cure cancer.
Discussing such a study in the popular press, or indeed commenting on the miracles claimed for MacKillop, will evoke strong responses because of strongly held beliefs. People should be free to choose their personal beliefs. But as a scientist, I can say there is no doubt that cancer outcomes on a population basis have improved significantly because of to the demonstrated benefits of evidence-based medicine.
There is one point, however, on which we can all agree.
A patient who has cancer and who is cured, by whatever means, offers cause for a celebration that we can all embrace.
— Ian Olver (medical oncologist and chief executive of Cancer Council Australia)