All in the mind: Can laughter cure cancer?

Helen, who has breast cancer, put it to me perfectly: "When I heard the word 'cancer', I couldn't understand anything you said to me after it. I was reeling, and all I could think was, 'This can't be happening to me'."

That sense of unreality is almost universal. Hundreds of people have told me exactly the same thing, even when, as in Helen's case, they understand clearly that their particular cancer poses a very small threat to health or life. The fact is that "cancer" is the most dreaded word in our language. We all have a tendency to think of it as if it were one single disease that is remorseless and unpredictable, and that almost seems to have "a mind of its own".

It's that "mind of its own" aspect that poses a major problem in itself. It has lent so much support over the last few decades to the idea that any cancer can be controlled, influenced or even cured in some way by the power of the mind of the sufferer. Some theories even proposed that the mind, or attitude, or "negative thoughts" of the patient might have contributed to the cause of the cancer in the first place.

I first realised how damaging this theory could be during the height of Dr Bernie Siegel's popularity in the late 1980s. He is the Yale-trained surgeon who believed that certain types of attitude and personality could make the patient live longer. He called these patients "e-Caps" (for "exceptional cancer patients"), and wrote several books that were immensely popular. In his writings and on television, he suggested that if you had a positive attitude and enough determination, you could control or even defeat your cancer.

In the middle of this surge of enthusiasm for the apparent anti-cancer effects of positive thinking, one of my patients, Dorothy, came into the clinic holding one of his books and on the verge of tears. She was very upset and actually quite bitter: "It says here that if I try hard enough, I could make the cancer go away, and if it doesn't, that's because I don't love my husband and three children enough."

This whole hypothesis – perhaps I can call it the "mind-over-cancer" theory – has actually been disproved in detail, and repeatedly. Even by the early 1990s, four major studies had shown that changing attitudes and the mind, while they certainly helped the patients to cope and to get a higher quality of life, didn't actually prolong survival. These studies involved major complementary medicine centres in California and in Bristol, both of which are flourishing, and continue to give a great deal of care and support to their appreciative patients and families, even without prolonging or saving life.

In addition to those cancer studies, Siegel – to his credit – participated in two other projects, which also showed that positive thinking and becoming one of the e-Caps did not prolong survival or produce extra cures.

But the idea that "you must always have positive thoughts" is still there. In my own clinic, not a week goes by without a patient asking me if stresses in life – marital, occupational, familial, financial – might somehow make the cancer worse. Mary, a wonderfully articulate university professor, said: "Now I'm even worried that the activity of being worried might do some damage. And that worry is worrying!"

Mary's comment hit the target. We all have stresses in our lives, and when something apparently mysterious happens, it's very easy to blame it on those stresses. In fact, one study of women with recurrent breast cancer suggested that a high-stress load might actually be associated with early recurrence. In that study, the women were asked to assess their stress-load at the time of recurrence – a time when it would be reasonable to see life as highly stressful. When the study was repeated, asking the women about stresses at the time of diagnosis (long before any recurrences had occurred) there was no link found. So stress – however unwelcome – doesn't hasten the progress of cancer.

One team, that of Dr David Spiegel in Stamford, looked at the effect of group-therapy on survival. In analysing the outcome of patients who had attended groups, they found an improved survival, and immediately committed themselves to repeating the study to see whether the results were just a fluke. Just this month, the repeat of that study was published. The design was a prospective one – in other words, the patients were divided into two groups right at the start, one group getting additional education and group-therapy; the other getting conventional care only. The results clearly showed no overall difference in survival, although looking back at various sub-groups, there was a slight benefit among those with the more aggressive breast cancers. This difference, found by looking back at sub-groups in the study, was not statistically significant – which means that it is not reliable and may have been just a fluke.

I interviewed Dr Spiegel for a TV programme some years ago, and he had a wonderful way of viewing the issues. He thought of group therapy and education as providing a genuine sense of community and peer-support, which changes a lot of attitudes and coping strategies. As he said, if you were walking through a dangerous neighbourhood of a big city alone at 3am, you'd feel very scared, but if you were in a group of a dozen people, your attitude, and perhaps your behaviour, might change.

It's not a matter of mind-over-cancer as much as improving one's abilities to cope. As I said to him back then, if his studies did show an improvement in survival, then every cancer centre should offer group-support. But if the studies didn't affect survival, we should still encourage group-support because it improves the quality of life. And quality of life, as one of my patients said, "is life itself, when you come to think about it".

I think that the era of mind-over-cancer was just another example of something that we human beings have done for millennia: blaming the patient for an apparently mysterious disease. In biblical times, everybody thought that leprosy was caused by poor hygiene. Until the 19th century, we thought that TB was caused by an artistic temperament. In the same era, people thought that Down's syndrome was caused by the parents being intoxicated at the moment of conception (and who hasn't done that?).

All of these are examples of our desire to pin the blame for a mysterious illness on something or anything. And the mental make-up of the patient will do if we can't find anything else. I hope that this is all drawing to a close now. We have identified more and more of the genetic factors – the DNA abnormalities – involved in many cancers, so that the mysteries surrounding them are slowly becoming fewer, and with them the spurious theories blaming the patient for the cause or the course of their particular disease.

I'm really glad things are moving steadily in that direction – after all, anybody with any form of cancer has got enough to cope with as it is.

Dr Buckman is an oncologist, a consultant at Princess Margaret Hospital, Toronto, and a professor at the University of Toronto. His latest book is Cancer is a Word, not a Sentence (www.cancerword.com)