Pain after cancer: A new model for pain psychology?

What if every headache, every slight twinge in your back, was potentially life threatening? What if you couldn’t tell a brain tumour from coffee-withdrawal? These can be constant, niggling worries for many people who have survived cancer, and we think their experiences can tell us something important about pain.

If you have read a Body in Mind blog post over the last few years you will likely have come across the idea that pain is all about meaning. Pain is about perceiving threat and danger to the body. The general idea is that the brain uses different types of information – including from the external and internal world through our senses, and from within brain centres that encode things like emotion and memory – to decide how much danger the body is in. The brain then produces an output based on all this information, the feeling of pain, to reflect that danger. Importantly, how we interpret painful sensations is an integral part of assigning meaning and making sense of those experiences.

So if pain is about threat – if it’s about meaning – an ideal model to study pain would be one where there is little tissue damage but a high level of perceived danger. Scientists have played around with this idea in the lab for a few decades now (like this cool study in adults and this ace study in kids). The trouble is; thanks to our cushty[1] modern ethics system, making lab participants feel like they are in extreme, life-threatening danger is understandably a bit of a no-go.

So what about outside the lab? A little while ago I became interested in the experience of pain following cancer treatment. Pain is not only a common experience during and after cancer treatment, but it is also one of the most common symptoms that leads to an initial cancer diagnosis. Many individuals live with pain for months before receiving a cancer diagnosis, making pain an experience that was ignored for so long but indicative of such grave danger.  It’s hardly surprising, then, that the experience of pain after cancer can be an anxiety-inducing event. Imagine you are given the ‘all clear’ and you are told to go out and live your life despite the near-constant fear that the cancer may return. How do you live within your body from that moment on? How do you judge a true from a false alarm?

When I have asked these questions at meetings over the last year, I often get the same response. “It’s better to be safe than sorry; you should always go to the doctor when you have pain that you’re unsure of”. “Only the paranoid survive”, as they say. The trouble is; pain is part of living a normal, active lifestyle. Pain is normal. Pain is frequent. Especially after surgery, radiotherapy, or chemotherapy. Going to the doctor every week with every new pain isn’t a viable solution.

Despite their unquestionable good intentions, the messages doctors and healthcare professionals give to patients following cancer treatment aren’t always helpful. A common message is “listen to your body; you know your body and when something isn’t right”. But if pain science has taught us anything over the last decade, it’s that we may not know our body so well. Our body, indeed our brain, can play tricks on us depending on the information we receive from the external world, through those pesky emotion and memory systems, and through our interpretation of those body sensations.

I’m going to preempt what you’re thinking now: of course, the most important thing is not to miss a cancer recurrence. We should never ignore pain for so long that we miss signs that the cancer has truly returned, therefore missing an opportunity for early intervention. But this isn’t the only thing that’s important. What’s also important is living a full and happy life after cancer. With as little anxiety and fear as possible. It’s a balance.  So the question is, how do we reduce fear and boost wellbeing after cancer survival? Especially for those who experience pain as a worry-inducing event?

We recently proposed a model that we hope will guide research in this area. Our Cancer Threat Interpretation (CTI) model describes how cognitive and affective processes such as interpretation, attention, fear, and decision-making interact to influence the pain experience after cancer. For example, for someone who experienced pain as an initial symptom of their cancer, and who is highly fearful that their cancer will return, we may expect them to be hypervigilant to pain sensations, to over-interpret pain sensations as threatening, and to become increasingly worried and fearful in the face of pain. And as previous studies in non-cancer pain (like this, this, and this) have hinted at, all of these biases may paradoxically increase their pain.

Going forward, the CTI model gives us clear targets for investigation and intervention: to help individuals disengage from pain, to help them consider alternative non-threatening interpretations, and to decrease fear and worry. All whilst remaining attentive to the reality that the cancer may return. This may seem like a difficult balance to strike, perhaps an impossible one. But the ethics and practical implications of striking this balance is a discussion that needs to be had, particularly as our cancer treatments continue to improve and survivorship rates continue to increase.

Studying where to strike that balance might tell us a lot about the psychology of human pain, that can extend to patients experiencing pain after acute injury, after surgery, and even for chronic non-cancer pain management. If we believe only the paranoid survive, how do we make this survival as joyful and worry-free as possible?

[1] ‘Cushty (adj) meaning generally positive, neat, well thought out, and often met with respectful regard. British, circa 2000s’

About Lauren Heathcote

Lauren is an experimental psychologist with a keen interest in all-things-research. She did her PhD at the University of Oxford (where they like to call a PhD ‘DPhil’), looking at the role of cognitive biases in adolescent non-cancer pain. She is now a postdoc in the anesthesiology department at Stanford University, where she is exploring the role of threat perception in adolescent chronic and post-cancer pain.

In her spare time, Lauren likes to climb Californian mountains, eat sushi, and salsa dance into the wee hours.

Reference

Heathcote, L.C., & Eccleston, C. (2017). Pain and cancer survival: A cognitive-affective model of symptom appraisal and the uncertain threat of disease recurrence. Pain, 158, 1187-1191.

 

Senior Commissioning Editor: Neil O’Connell