Bone pain management for cancer patients
Dr Raghavendra Ramanjulu - Health Care Global, Bengaluru, India
Bone pain is one of the commonest of the cancer pains we come across and it is difficult to manage too. The pain is not only affecting his daily to daily activity, added to that he has got a lot of comorbidities to come across when bone pain starts. His mobility is gone; his issues of food intake and other things and dependency on others start building up. So therefore sitting up in the bed also could be an issue and it starts to come to pain.
What are the non-pharmacological treatments available for bone pain?
Non-pharmacological methods are as equally important as pharmacological methods too because the patient understands that we are there with them, we are reassuring them, we are talking to them and finding out each simple issue of what is causing them pain. Now, to give a simple example, in my cultural context squatting to open bowels is something very, very common and I’ve found that they were not able to squat because all the central bones like pelvic, hip, back, is what is involved. So just simply saying to them to put a chair to open their bowels actually gets their pain down by almost 50-60%.
What are the pharmacological treatments available for bone pain?
We can act against the cancer itself; we can actually give painkillers itself to actually get down this pain. So one of the other features is breaking of bones which are occurring because of skeletal related events wherein the osteoclastic activity or the osteoblastic activity is going on. That could be arrested with some of the medications. The last would be the radiation which is a most important crux of handling this bone pain. Now, radiation if it is given, which is the best of the evidence to last for for some time, it takes about fifteen days so in the meanwhile we need some medications to act at that point of time to the treatment is done for the patient to become better.
First coming on to our WHO ladder NSAIDs, COX-2 inhibitors are of level grade 2B of evidence to be used. It decreases the blood supply, decreases the neoangiogenesis as well as the tumour burden and load is also decreased by the NSAIDs. So COX-2 inhibitors are much more specific and it protects the gastric mucosa too. These are two things which are very, very important.
To top this we have had the opioids. Tramadol and codeine are weak opioids which do not have any role or evidence to use and tramadol actually causing more nausea and vomiting. There are certain studies which put across tapentadol which is a better congener compared to tramadol for the pain relief itself and that has been studied in multiple myeloma patients for a longer duration of time with extended release tablets of tapentadol. Coming the strong opioids, morphine becomes the rank; we know that morphine is a good pain relief when other side effects are handled very well. The oxycodone, if it is severe neuropathic pain, has got a little bit of evidence otherwise there’s nothing to prove beyond morphine. Fentanyl is something which is better off, compared to morphine, when constipation becomes a major issue for this group of patients. Coming next is methadone; yes, it’s got a better comfort zone, the patient is better, but it requires the correct accurate assessment of the patient as well as conversion, rotation of opioids from morphine to methadone so therefore you need a specialist palliative care person doing that.
So this will be there but when we mix opioids with a COX-2 inhibitor the opioids usually increase the blood supply, increase tumour load whereas the reverse is happening with the COX-2 inhibitors. So a combination works better. To add to this paracetamol is definitely there so I would suggest the addition of paracetamol at all points of time could be at the specific doses for adults or paediatric too.
Next, coming to the anti-seizure medications, gabapentin is the only drug which has shown a little bit of good response to this for the neuropathic pain which could be the sensitisation which I mentioned before, primary or secondary. The TCAs and other things do not have much role or the evidence is not backing up that very well.
What are the latest treatments surrounding bisphosphonates in the treatment of bone pain?
Zoledronic acid has proved to be much better in comparison to the other congeners which are there and it’s a Cochrane review which says that the number needed to treat would be around eleven numbers for having a response of 50% could be to reduce skeletal related events at four weeks and could be seven by twelve weeks as well as comorbidity to come down. So zoledronic acid is better among all the bisphosphonates.
Next, adding on to this, the major issue of the bone metastasis, why it occurs, acting at the receptor level is the rank ligator, that’s the denosumab which is a monoclonal antibody, IgG, which is actually acting at it to arrest the metastasis itself and the further effects.
When can radiological and surgical interventions be introduced?
Radiotherapy is something which is very, very important. It’s got the best evidence among the treatment, other than the non-pharmacological, that is the opioid rank which is the number needed to treat as two. The radiological would be, to start off with, a single fraction of 8Gy or it could be 30Gy in ten days or heavy body radiation depends upon where and what type of tumour metastasis the patient has got. Next would be to have radioisotopes. If they have actually spread a lot strontium-132 is something which has been used for. So, other than these, surgical interventions are required when patients have got skeletal related events or, too, to prevent any fractures. If Mirel scoring is bad you can use these to be in advance itself. To top this there are some interventional pain medicine guys could do or help to actually lessen this pain. It could be ablation of nerves or ablation of the spinal cord or intrathecal pumps or even the tumour itself could be radiofrequency ablated. So these are some of the things which could be done.