Kylie Minogue, stress and cancer, chicken or egg?

Australian pop singer, songwriter and actress, Kylie Minogue, 42, worries that is could have been stress that made her sick five years ago when she was diagnosed with breast cancer. There are a lot of articles in medical journals that link stress and various diseases, including cancer, and the link between stress and disease is thought to be through our immune systems. In fact, there is even a special name for the field that studies the role that the mind can play in health and disease: psycho-neuro-immunology.

What exactly is stress? Are there different kinds? Under what circumstances is stress (anxiety) a disease in itself?

Physiological stress, also known as the fight or flight response, is an ancient mechanism that humans share with animals that allows us to cope with immediate dangers such as stalking and attack by predators. When our nervous systems perceive a potentially dangerous situation, special structures in our brains (namely the hypothalamus and pituitary glands) send chemical messages through the blood stream to our adrenal glands (which sit just on top of our kidneys). Our adrenal glands then release the hormones adrenaline (also known as epinephrine) and a steroid called cortisol. These hormones travel via the blood stream to other organs and cause the following effects on our bodies:

• Redirect blood from less vital to more vital organs
• Increase our heart rate and blood pressure to supply blood more quickly and efficiently
• Increase our breathing rate to get more oxygen into our blood
• Break down complex carbohydrates in our livers and muscles to get more sugar (glucose) into our blood

It is important to understand that this response is rapid and brief and gives us extra energy and concentration to deal with immediate threats. This acute stress response evolved as a survival mechanism and is therefore generally a normal, healthy way in which our bodies and minds deal with danger. In our ancestors on the savannah, this could have meant escape from being killed and eaten by a lion. Unfortunately, this fight or flight response can be triggered by many non-life-threatening situations and frequent, repeated triggering of this stress response leads to chronic stress which is a decidedly unhealthy state. For example, chronically elevated cortisol can suppress your immune system leading to increased susceptibility to infections and perhaps even other diseases such as cancers. (Incidentally, artificial forms of cortisol such as prednisone, are used medically as drugs to suppress over-active immune responses in diseases such as asthma and lups, or to prevent rejection of organ transplants.)

Psychological stress, or anxiety, is not entirely separate from physiological stress and serves to heighten concentration and focus in fight-or-flight situations. Again, anxiety is generally a normal, transient an self-limited way that our bodies and minds respond to life events. There are many ways to naturally cope with anxiety such as exercise to “burn off” stress hormones or meditation (called The Relaxation Response, a book by Dr. Herbert Benson that has been in print for almost 40 years). However, anxiety can become so severe and unrelenting that it becomes a mental health disorder.

As we’ve covered in a number of other stories, doctors diagnose mental disorders using rules spelled out in a book called DSM-IV (the fourth edition of the Diagnostic Manual of Mental Disorders published by the American Psychiatric Association). There are a number of different anxiety disorders, such as Obsessive-Compulsive Disorder (OCD) and post-traumatic stress disorder (PTSD). Each of these disorders have distinct features and require careful assessment by a mental health professional, guided by diagnostic features spelled out in DSM-IV. As an example, we include below the diagnostic criteria for generalized anxiety disorder (GAD):

Anxiety disorders are serious medical illnesses that can be successfully treated by psychotherapy and/or pharmacotherapy (medications).

So in Kylie’s case what came first, the cancer or the stress? It’s really impossible to say. The important thing is that she has overcome both.

Editor’s note: The case of Kylie Minogue’s breast cancer in 2005, and its effect on public health awareness, was an important motivator for us to create Celebrity Diagnosis™. The publicity surrounding her case stimulated a 20-fold increase in news coverage of breast cancer and the fact that early detection was critical. Likewise, Jade Goody’s public struggle with cervical cancer was lauded as a great public service because it encouraged thousands of women to seek prevention and screening advice. Articles in medical journals have studied this link between celebrity illness and health awareness and concluded that highly-publicized illnesses present opportunities to improve public health (but also have the potential to lead inappropriate and over-use of medical services). The mission of Celebrity Diagnosis™ is to systematically highlight and explain “common diseases affective uncommon people” to increase health awareness and medical knowledge and to enable participatory, personalized medicine.