Module 4: Cancer Related Bone Pain

 SURG0132: Pain in Cancer Patients

As I pause to reflect on this module, the 4th in the degree so far, I am struck by how quickly it’s all passing by! I feel that I have learned so much, yet have so much more to learn.

As the title suggests, this module was about bone pain in cancer patients. I had not really given this much thought, as it’s not something I come across in clinical practice very often, in some years, not at all. I had always attributed bone pain to the presence of a tumour itself, although I was aware that pressure or distortion from the tumour upon the surrounding tissues would be likely to cause pain. I was also aware of the distortional effects through the myofascia, or from the literal mechanical effects of cancer – eg a tumour compressing a nerve. Considering the underlying patho-neuro-physiological changes that are taking place is a new concept for me. Patients who have had treatment for cancer often tell me about their experiences of the detrimental effects of cancer treatments themselves, such as peripheral neuropathy. I had assumed that once these changes had taken place, they were irreversible – now I know that this is not necessarily so.

The first part of the module covered the pathological and physiological mechanisms. Peripheral sensitisation occurs in cancer pain as well as non-cancer pain, the difference is what happens on a molecular level within the tumour itself. The tumour creates its own microenvironment and generates pain by secreting molecules that directly act upon the pain signalling pathways.
It was interesting to learn that cancer cells which have spread to the bone cause disruption to the bony matrix, resulting in two types of lesions - osteolytic (destructive) and osteoblastic (causing enlargement by stimulating the production of extra cells). The type of activity that occurs depends on where the primary cancer started.

Assessing specific cancer-related pain was new to me. The basic history-taking wasn’t really any different, but I have never used pain rating tools other than the standard VAS 1-10 scale. Cancer pain requires a more biopsychosocial approach. A VAS scale doesn’t tell you anything about what kind of pain it is, or how it’s affecting the patient. I spent more time reviewing the painDETECT questionnaire, and the neuropathic pain questionnaire (NPQ), and will add certain aspects from them to my MSK history taking to refine where the patient’s pain likely originates.

A totally new concept for me was learning about intrathecal drug administration, and about Ziconotide in particular. I had heard about venomous cone snails a long time ago when I went scuba diving, and I think it’s terrific that the venom from a creature so small and pretty could lead to such a good alternative to managing cancer pain than the common opioids. Drugs which bypass the blood-brain barrier lead to faster therapeutic action with fewer systemic side effects. 

I do treat children, but not for cancer pain. The course material spoke about proxy reporting of children’s pain, and how this can be distorted by the parents’ viewpoint and understanding of their child’s situation, the projection of their fears/anxieties or past experiences which may influence the child, but also by the treating medics and nursing staff.
Often, babies are brought in to see me for osteopathic treatment by parents looking for relief for their child’s colic/reflux or birth trauma. I also see younger children for simple MSK stuff. Since learning about the FLACC Behavioural Rating Scale, I can now better measure my non-verbal patient’s discomfort and more accurately track their progress, having incorporated this scale within my paediatric assessment notes template. For older children, I have printed out the Wong-Baker Faces Scale, so they can point firstly where it hurts on themselves and then to the face which corresponds to how the pain makes them feel. This may possibly help to take parental influence out of the scenario to get a truer estimation of my patient’s pain. The child may also feel that they are being talked to as well as listened to rather than ‘at’, and as a result. may actively get involved in their case-history taking.

With the differing mechanisms of pain going on within the patient, the management of pain in cancer requires a multi-disciplinary approach. Like chronic or acute pain, this management is only as good as the team providing it, so the importance of good teamwork can’t be understated. The patient’s past experiences, perceptions and wishes should always be central to decision-making.
Although I’m not working within the NHS, I feel I can be of use to patients suffering from cancer-related pain. I do see terminally ill patients from time to time. I’m told that one aspect of the help I give is that I provide a safe space in which they can talk about anything whilst having their treatment. Being away from other relatives and caregivers gives them the freedom to say whatever they need to, to vent anger, to get philosophical, or just simply be in a different place that is not associated with end-of-life care. 
Depending on the patient’s needs, my treatment can be basic massage, myofascial release techniques or cranial osteopathy (likely a mix of the three), all of which lead to a reduction of stress and therefore central sensitisation, plus stimulate the endogenous endorphin pathway to enable pain relief and enhance feelings of well-being. 
I found some research about treating myofascial release points in patients with advanced cancer (Hasuo et al., 2016). They looked at patients who exhibited antalgic pain postures, which gave rise to trigger points within certain muscles. They showed that releasing said trigger points gave good pain relief and reduced the necessity for high opiate dosing. Despite their patients being very different from those I have treated (theirs were delirious secondary to high dosages of opiates, mine normally are not!), I plan to look for similar myofascial points/patterns of pain in future patients who are suffering cancer-related pain.

 

 

References:
Hasuo, H., Ishihara, T., Kanbara, K. and Fukunaga, M. (2016). Myofascial trigger points in advanced cancer patients. Indian Journal of Palliative Care, 22(1), p.80. doi:https://doi.org/10.4103/0973-1075.173956.