Introduction
Unfortunately, cancer is very common here in Australia and around the world. Statistics indicate that 50% of Australians will contract a form of cancer by the time they are 85 years old.
People with cancer will invariably experience some of form of pain as a result of the disease, either before diagnosis and after diagnosis and during treatment. Around 55% of cancer patients have pain during treatment (with 66% of people with advanced cancer having related pain) and 39% of people with cancer report pain after treatment has been completed. As survival from cancer is improving every year that means more people in our communities will have pain from cancer and its treatment.
Cancer pain is classified according to two broad criteria…
How long it lasts
Continuous pain is regarded as 'chronic' if it continues for longer than 3-6 months and 'acute' if it continues for a shorter period than this. If pain only occurs when making a particular movement (for example sitting down or standing up) this is described as 'incident pain', which may be severe, but subsides relatively quickly.
The origin of the pain
Pain is classified as to how it is caused. This refers generally to the mechanism creating the pain, not the part of the body that is causing the pain as such. There are a number of potential origins of pain…
Nociceptive pain
'Nociception' describes the body's mechanism of transmitting pain signals to the brain via nerve fibres. This is what happens when you injure yourself – nerve fibres from the injury transmit a signal to the brain which feels like a sharp pain at first and dulls into a general ache.
Neuropathic pain
Neuropathic pain occurs as a result of some damage to nerve fibres. This damage then prevents the nerves from transmitting the normal pain signals and generally results in 'false' sensations of pain (for example burning, tingling – 'pins and needles', or a short shock-type pain) where there is no injury. Neuropathic pain can also result from a tumour pressing against a nerve (see below).
Visceral pain
Visceral pain describes any pain that comes from an organ within the body, such as appendicitis causing abdominal pain. It is often hard to say where the pain is coming from in anything but very general terms, and often causes nausea and in extreme cases, vomiting.
Phantom pain
Phantom pain is where a person feels a sensation of pain from a part of the body that has been removed – for example from a mastectomy, or removal of a part of a limb.
Causes
The actual cause of cancer pain can be caused by a range of different factors. Common causes include…
Pain from the tumour itself
Tumours can cause pain by putting pressure on or damaging surrounding parts of the body such as nerves, organs or bones, and due to their size can cause pain through blockage e.g. a tumour in the bowel.
Pain due to treatment
Quite commonly pain can persist after surgery even when the surgery is successful. Other forms of treatment such as chemotherapy and radiotherapy can also cause pain, for example nerve pain in the legs can occur even years after some chemotherapy treatment.
Pain unrelated to the cancer
Patients with cancer get pain just like anyone else. All the normal pains that people experience, like back pain, occur in someone’s cancer journey and should be well treated to keep people healthy and fit to get through their treatments.
Managing pain from cancer
The key to managing cancer pain is to report it. The health team take pain seriously as it affects patients significantly and there are a host of people able to assist from GP’s and Oncologists to pain specialists and palliative care physicians.
There are options to manage pain and patients with cancer or survivors of cancer should not put up with uncontrolled pain.
On the whole, most pain is manageable with medications and the best form of pain management is treating the cancer itself. However, if pain is not controlled, discuss it with your GP and Oncologist as other forms of pain management exist such as nerve block injections or even implantable treatments.
Referral to a specialist helps with the pain, helps in making right treatment decisions and getting through treatment itself.