Dr Cathryn Walton explains how pain management in oncology works.
Pain is the most commonly feared symptom in a cancer patient. It is also the most misunderstood symptom. Fifty percent of patients have some form of pain at diagnosis of cancer. Thirty percent will have pain during treatment but 90% have pain as a symptom at the end of life.
With a better understanding of pain and the management thereof, patients can feel in control of their lives. They have an improved quality of life and functionality.
The management of pain in oncology is complex. It’s more than just pills and syrups. Because pain affects every aspect of a patient’s psychosocial being, pain must be managed on all these levels.
Causes of pain in oncology
• Tumour invasion – the tumour may invade the bones, nerves and organs resulting in weakness of the organs and dysfunction.
• Diagnosis and treatment – to make a diagnosis, there are often a series of painful procedures and surgeries. Various forms of treatments can also result in pain – even if only temporary – e.g. radiation may cause a skin reaction. Some chemotherapies may cause a burning sensation when they’re administered, and may result in long-standing pins and needles of the hands and feet.
• Pain unrelated to malignancy – myocardial infarction, peptic ulcer and arthritis.
Few of us have gone through life without experiencing some form of pain.When we fall off a bike and injure ourselves, we know most often, the body will attempt to heal itself. Although the pain is present, it becomes less intense with time and eventually disappears.
However, when you have chronic pain or cancer associated pain, you have to realise that this process will persist until the cause is dealt with. If the cause is early malignancy that can be treated and cured, the need for pain medication will be temporary. If the malignancy is incurable, the pain will persist and there will always be a need for medication. Because of this, you’ll need to change the mindset of only taking pain medication when you have pain. The trick is to prevent the onset of pain.
Think of oncological-related pain as a wheel that is continually turning. As the wheel turns, a method is needed to stop the pain cycle and prevent it from returning.
It’s not always necessary to use high doses of medication, but it is often necessary to use low doses of strong medication at appropriate times, to stop the wheel and keep it stationary.
Ways to reduce pain in oncology
There are many medications and techniques available that work on various places on the wheel to prevent pain. Often, it’s a balance between treating the pain as well as treating the cancer.
Chemotherapy and radiation are the most commonly used methods to treat cancer. The shrinkage of cancer results in less infiltration and pressure on organs surrounding the cancer. This results in less pain.
Radiation uses high energy to disrupt the DNA of the cancer cell. This stops the cell from growing and the cell dies off. Radiation is often used on a specific site of the body that has pain as a result of cancer. For example, back pain as a result of cancer spreading to the vertebra.
Chemotherapy is a systemic form of therapy that, through a wide range of mechanisms, disrupts the cell cycle sufficiently to stop the propagation of new cells and kill cancer cells. The spread of cancer is potentially prevented or reduced.
Analgesics are a wide range of medications that act on various sites in the body to treat and prevent pain. The most important factor is to use the right type of medication for the right type of pain, in the right quantities, and at the right intervals to gain adequate pain control.
The choice to use a specific analgesic is not made lightly. The doctor often asks a wide range of questions to decide what medication, how much and at what times these need to be given.
They can be given in various forms – patches, tablets, capsules, syrups or suppositories – depending on the mechanism of action of the analgesia as well as a patient’s ability to swallow, for example. Often a combination of medications are used to achieve maximum effect.
• Antidepressants, antiepileptics and anxiolytics are medications used on the central nervous system (the brain) to alter a patient’s perception of pain. They are often used in combination with routine analgesics.
• Psychotherapy, physiotherapy and other techniques are employed to assist the patient with pain. An immobile patient suffers more pain because of muscle and joint stiffness; exercising and mobilisation release endorphins.
MEET OUR EXPERT – Dr Cathryn Walton
Dr Cathryn Walton is a radiation and clinical oncologist working at Cancercare in Port Elizabeth. She has special interests in breast cancer, lymphoma, melanoma, and palliative care of the terminally ill.