CANCER AND MIND - IS THERE A RELATIONSHIP?
by Sarah Edelman 

Anna has been a successful career woman. At the age of 34 she held a highly paid job as a financial planner in a large trading company. In recent years the stress of the job has taken its toll. She frequently went for weeks at a time without eating proper meals, contacting friends or taking time out to relax. Even when sick with the 'flu, Anna went to work to finish a project that she had been working on. However, all of that came to an abrupt halt in 1994 when Anna was diagnosed with breast cancer. In hindsight, she is not surprised. Given her lifestyle, it was only a matter of time before her health gave out. 

Anna is one of the many women that I have dealt with who believes that she is responsible for bringing cancer into her life. Other women have cited experiences such as marital breakdown, relationship conflicts, financial problems and personal crises as factors contributing to their disease. 

The idea that cancer is caused by mental factors has been promoted by numerous self-help books that became popular in the 1980's. Books such as Love, Medicine and Miracles (Siegal), You Can Conquer Cancer (Gawler) and Getting Well Again (Mathews-Simonton) have suggested that stress, negative thinking and emotional conflicts can weaken the body's immunity and allow cancers to develop. Some New Age writers have gone further to argue that "we create cancer for a reason", citing unconscious motives (such as the pursuit of lessons that need to be learned) as factors which trigger the disease. 

To many patients, this view holds enormous appeal. It provides an explanation for something that is otherwise unexplainable and gives meaning to the experience. It suggests that we are not just the helpless victims of random biological processes, but that our thoughts and feelings can have a direct influence on our health. As one woman put it, "If I caused my cancer, then I can also cure it". 

Unfortunately, this belief can also create unnecessary stress or guilt, as in the case of a woman in our study who believes that her unhappy marriage and acrimonious divorce were the cause of her disease. Far from creating a sense of control, the belief has made her angry and bitter. Other participants have reported feelings of guilt and regret for having "created" their disease, or for "not having been positive enough to have stopped its spread". 

In the course of my work, I have heard many anecdotes of patients who have changed their attitudes and lifestyle, and subsequently lived long and healthy lives, in defiance of the odds. Others have told me that they were diagnosed shortly after a personal crisis, or after a prolonged period of stress. While these stories are interesting, they are not in themselves evidence for a mind-cancer connection. After all, there may well be millions of negative, highly-stressed people who never develop cancer, and there are certainly some very positive ones who do. As a researcher, part of my job is to explore the question: "What is the evidence that psychological factors can cause cancer or influence its course?" The following is a description of some of the findings to date. 

Effects of Stress on the Immune System 

Most of the research examining the relationship between psycho-social factors and cancer has been done in the last 20 years in the newly emerged field of `psycho-oncology'. A major hypothesis underlying much of the work has been that stress might increase vulnerability to cancer through its effects on the immune system. 

Several studies have already established that stressful events can cause deregulation of immunity. Studies with medical students showed them to have suppressed immune responses during their final exam period. Lonely students were found to have poorer immunity than those with good social support. Women in their first year of marital separation had poorer immunity than non-separated women, and amongst married women a poorer state of the marriage was associated with poorer immune response. A study of family carers to Alzheimer's disease patients has also shown immuno-suppression within this group. Interestingly, studies of individuals who practised regular deep-relaxation have shown improvements on various aspects of immunity. 

Stress and Onset of Cancer 

While there is good evidence that stress can compromise the immune system, there is no clear evidence that stress-related immuno-suppression causes cancer. Studies that have examined the relationship between stressful life-events and onset of cancer have produced contradictory findings. 

Some studies have found that cancer patients were more likely than healthy `controls' to have experienced major life stresses in the period before their diagnosis: others have found no such effect. Unfortunately, many of these studies were retrospective (meaning that patients were asked about their stress after they were diagnosed with cancer) and were therefore subject to bias, as people naturally tend to look for past events to explain their illness. 

Better methodology comes from prospective studies, where people's stress levels are assessed before they develop cancer. Because prospective studies require large sample sizes and long periods of time, very few investigators have been willing to undertake them. 

A recent semi-prospective study reported on 119 women who had been recalled for biopsy following the discovery of suspicious breast lumps. Whilst their diagnosis was still unknown, the women were asked to provide information on the number and degree of stressful life events that they had experienced in the previous five years. The findings revealed that amongst the 41 women who were subsequently diagnosed with breast cancer, the incidence of severely stressful life events was three times higher than amongst the other women whose symptoms were benign. This was an important study, as the women were assessed before their diagnosis was known (thereby reducing the risk of bias). However, unless the findings can be replicated, they must be treated with caution. 

A third research approach has been through epidemiological studies, which examine the incidence of cancer amongst highly stressed groups, such as bereaved and depressed people. It is interesting to note that with a few notable exceptions, most epidemiological studies have failed to find a higher incidence of cancer amongst these `stressed' groups than amongst the general population. 

Studies have also examined the effect of stress on disease progression amongst people who already have cancer. Patients who are in remission have been assessed on the degree of stress that they are experiencing, and were then followed several years later. The findings have once again been mixed. Some of these studies found that patients who had experienced high levels of stress were also more likely to relapse or die in the interim period. However, other studies have found no relationship between stress and progression of the disease. 

At this stage at least, it seems that the evidence for a relationship between stress and the development of cancer is highly equivocal. 

Attitudes and Coping Style 

Other research has focused not on the effects of stress per se, but on factors such as attitudes and coping style. Several studies have identified specific attitudes that frequently accompany good or poor prognosis amongst people who already have cancer. Of these, the most frequently cited have been fighting spirit versus helplessness/hopelessness, and the expression versus repression of emotions. 

Helplessness/Hopelessness 

In one famous British study, the coping style of breast cancer patients was assessed at three months following mastectomy. The women were then followed up at five, ten and fifteen year intervals. The follow-up studies revealed that the women whose coping style had previously been categorised as either "fighting spirit" or "denial" were much more likely to be alive and recurrence-free, compared to those categorised as "stoic" or "helpless/hopeless". These results were very provocative and further replication studies are now under way. 

Helplessness has also been associated with poorer outcome in rodent studies. Rats that were made helpless through stressors such as crowding or footshock showed a suppressed immune response and more rapid tumour growth. They were also less likely to reject an induced tumour and more likely to die. However, when these rats were able to exercise some control (for instance by fighting or by terminating footshock with a lever), they showed no immuno-suppressive effect and no increase in the rate of tumour growth. While there are obviously problems with generalising from animal studies to the human context, this research supports the findings of human studies which suggest that helplessness is associated with poorer prognosis. 

Some research has also suggested that hopelessness might be a risk factor for the onset of cancer. In a recent Finnish study, 2428 middle-aged men were assessed on levels of "hopelessness". A follow-up study conducted six years later found that those who had been previously identified as "high" on hopelessness were three times more likely to have died of heart disease and twice as likely to have died of cancer during the interim period, compared to those who had been identified as "low" on hopelessness. Because the study was `prospective' (ie, it started with healthy individuals and followed them up over time), it provides highly credible evidence that attitudes might play a role in the onset of diseases such as heart disease and cancer. 

In another well-known study, women who presented for biopsy following abnormal pap smears were given psychological assessments before their diagnosis was known. Those who reported that they typically responded to stress with high levels of hopelessness were subsequently found to be more likely to receive a positive diagnosis (ie, had cervical cancer). This study does not prove that hopelessness causes cervical cancer. For instance, it may be that the biological changes caused by the disease affect psychological outlook rather than the other way around. However, it provides some supporting evidence that a state of hopelessness might play a role in the disease. Clearly, there is a need for further investigation in this area. 

Emotional Suppression 

In the 1970's movie, `Manhattan', Woody Allen says "I never show my feelings, I just grow a tumour", reflecting the common perception that cancer is related to repression of emotions. In fact, several studies have cited a higher incidence of cancer and more negative outcomes amongst patients who avoid expressing emotions. The mechanisms underlying this process are unclear. Some researchers have suggested that emotional suppression creates a higher level of physiological activation, which if not resolved, is more likely to create biochemical imbalances that allow disease to develop. As some studies have failed to find any effect related to emotional suppression, this area continues to be an important focus for further research. 

Social Support 

There is strong evidence that friendships and intimacy are not only good for the soul, but good for you health as well. Several studies have shown that individuals who have little or no social support have poorer immunity, more frequent illness and higher death rates from a range of causes, including cancer. Amongst people who already have cancer, those who are married or have good social support have slightly better outcomes than those who don't. Even animals need affiliation and show poorer health and higher incidence of death when they are isolated. 

Effects of Psychotherapy 

Some researchers have gone a step further to ask whether psychological intervention could influence the course of disease progression among cancer patients. If factors like social support, emotional expression, a fighting spirit and a perception of control might have a positive effect on prognosis, then perhaps psychotherapy which helps patients to acquire some of these qualities could also have a positive effect. 

One very well-known study that investigated this question is that of Dr David Spiegel and his colleagues at Stanford University. Women with metastatic (secondary) breast cancer were randomly assigned to either a support-group or a non-therapy control group. Both groups received routine oncology care, however patients in the therapy group also attended weekly support-group sessions. The therapy encouraged expression of emotions and the development of supportive relationships within the group. While the women who received therapy showed less anxiety and depression than those who didn't, the more dramatic finding occurred at the ten year follow-up: those who had been in the support group were found to have survived (on average) for twice as long as those who had not. The publication of this study generated lots of interest and discussion, and has encouraged other researchers around the world to conduct similar trials. Of the small number of studies that have been published so far, the results have once again been inconsistent, with some positive and some negative findings being reported. 

At the Neurobiology Research Unit at the University of Technology in Sydney, we are examining the effects of a group-psychotherapy program for women who have metastatic (secondary) breast cancer. Participants attend 12 sessions of Cognitive Behaviour Therapy, which aims to encourage emotional expression, improve psychological outlook and generate a sense of control. The women are also encouraged to make positive lifestyle changes, which include strengthening social support and practising regular relaxation. Through this research, we hope to assess the effectiveness of our program in improving the emotional state and quality of life of participants. 

We are also monitoring the women's health to determine whether participation in therapy can influence the disease itself. In 1997, we will be extending this research to include women who have less advanced breast cancer (stage I and II) and patients (male and female) who have metastatic colo-rectal cancers. 

Conclusion 

So what are we to make of the research so far? How do the findings stack up with statements made by the popular media suggesting a connection between mind and cancer? The short answer is that we still really don't know. While some of the research findings have been encouraging, the large number of inconsistent and contradictory findings caution against drawing any firm conclusions at this stage. 

To summarise the state of the research so far: 

The evidence for a relationship between stress and cancer is highly equivocal. 
There is reasonably good evidence that strong social support is a factor that reduces the risk of death and illness from a variety of causes, including cancer. 
There is some evidence that a perception of control and/or a fighting spirit may be associated with better outcome amongst cancer patients. 
There is some evidence that factors such as emotional suppression and a high degree of hopelessness may be associated with poorer outcome and a higher risk of cancer onset. However, this remains unclear. 
There is also limited evidence that psychotherapy might improve survival odds amongst patients who have cancer. However, the evidence is also highly equivocal. 
Pycho-oncology is a new scientific discipline - barely 25 years old, and as with any new field there have been teething problems. Many of the past studies have been flawed by poor methodology, which may explain the inconsistent findings. The good news is that the methodology being used in more recent studies is increasingly rigorous, and we therefore expect to see more reliable and consistent findings in the near future. Hopefully we'll have a better idea of any relationship between mind and cancer within the next decade. 

Sarah Edelman (MA) is Research Officer at the Neurobiology Unit of the University of Technology, Sydney, and together with Dr Antony Kidman is researching the effects of psychotherapy for cancer patients. They are seeking breast cancer patients who would like to participate in the study. For more information call (02) 9514 4309 or 9514 4077.