Pain

According to Hong Kong Cancer Patients, pain is one of the most common and most feared symptoms felt by cancer patients. Pain presents with varying intensities at varying intervals. On average, 7 out of 10 cancer patients experience severe pain.

Effects

• Physical:
  • Physical pain can lead to tiredness and has a negative impact on daily activities and appetite
• Social
  • Pain can also affect quality time spent with family and friends, leading to a lower quality of life.
• Spiritual
  • Pain can cause patients to question why they are suffering. It can develop into guilt and queries about the purpose and meaning of life and the role of religions.
• Psychological
  • The negative impact of pain on sleeping can lead to emotional instability, loneliness, depression, anger, and anxiety.

Scopes of effects

• Work, chores or daily activity (84%)
• Sleep quality (82%)
• Appetite (81%)
• Body weight (78%)
• Receive anti-cancer treatments (51%)

Pain does not necessarily mean that the patient’s illness has worsened, or that it is the end. Getting help as soon as possible can provide much needed relief. It is not always necessary to see it the difficult way.

From the cancer itself:

• Nerve pain due to proximity of tumour to nearby nerves
• Muscle/organ pain due to compression of the spine by the tumour
• Bone pain when the cancer metastasises to the bone 

From cancer treatment:

• Nerve pain as a side effect of chemotherapy/radiotherapy/surgery
• Nerve damage, phantom limb pain (after amputation), chest pain and breast pain (after mastectomy)

Unrelated to the tumour or treatment:

• Joint degeneration from insufficient activity
• Bone and muscle strain from overactivity
• Sore muscles, cramps and stitches from incorrect/uncomfortable posture

A. According to the cause of pain

Nociceptive pain

When the body is damaged, it is detected by nociceptive pain receptors which are concentrated mostly on the skin and organs.

These receptors are stimulated when the body is injured, sending many signals to the brain. Thus, people feel pain after these signals are converted inside the brain.

The two types of Nociceptive pain are:

• Visceral pain
  • Caused by damage to the organs
  • Uneasy to locate the source of pain, which can only be done approximately.
  • Best described as:
    • Compression
    • Soreness
    • Cramping
• Somatic pain
  • Caused by stimulation to the skin, muscles, bones, tendons and joints (non-organ related)
  • Easier to identify the precise location of the pain
  • Usually longer lasting

Neuropathic pain

• Caused by damage to the nervous system, or just a lack of synchronisation.
• Neurons (nerve cells) send abnormal pain signals to the brain, causing the body to feel pain even when there is no physical damage.
• It can be described as:
  • A burning sensation
  • Numbness
  • Getting pricked by needles
  • Sudden, flashing pain
  • Mild electric shock

B. According to duration of the pain

Pain management is an important aspect of cancer treatment.

Pain will persist and recur if it is not properly diagnosed and treated as below:

[Pain → Negative impact on daily life, such as appetite loss, weight loss and lack of sleep → Unable to receive anti-cancer treatment → Poor response to anti-cancer treatment → Pain persists or even worsens]

Aims of pain management in cancer patients are reduce the patient’s suffering and limiting its impacts on the patient’s daily life.

Notes to pay attention to as a patient:

• Honesty and transparency is the best policy when communicating with the doctor and other health professionals. Being patient and trusting the process of treatment will do better than harm. The prescription medications could sometimes take up to several days to show effects, which does not mean they are not working entirely. It is highly dangerous to stop taking medicine without a doctor’s advice, or to adjust dosages against the doctor’s instructions! The more proactive one is at starting treatment early on, the earlier they can effectively manage pain.
• Do not wait until the pain becomes unbearable before taking pain medication.
• If one only takes painkillers when they start feeling pain, theses medications will not always act immediately. One may need higher doses which can compromise your health. 

Painkillers

• Opioid painkillers have wider prescription tolerances compared to other types. The doctor will adjust medication prescriptions based on how well the treatment is progressing, or how the patient’s body reacts to them.
• Painkillers prescribed by doctors and are generally very safe. 
  • Side effects are few and far between. They could go away over time.
  • Under supervision of the doctor, addiction to any prescribed medication is nearly impossible.

Company during treatment

Fights against cancer are long and difficult if fought alone. However, with a support network of your loved ones, friends and health professionals like doctors, patients will never walk alone. Throughout the course of treatment, you will enjoy the company of an extensive support network. This could include:

• Family and friends
• Oncologists
• Palliative care specialists and anaesthesiologists 
• Nurses 
• Social workers 
• Clinical psychologists 
• Physiotherapists
• Chaplains (catering to multiple faiths)
• Occupational therapists

Opioids are further categorised as immediate-release and long-acting medications.

Immediate-release

• Quick alleviation of sudden pain
• Each dose generally effective from 4-6 hours after taking it

Long-acting

• Can be regarded as the basis for pain management
• Only two prescribed doses per day
• The concentration of the opioid in the blood must be tightly controlled for effective 24-hour pain suppression

According to the European Association for Palliative Care, doctors will prescribe correct dosages and types of pain medication according to the amount of pain their patients are suffering from. For example:

• Mild pain
  • Non-opioid painkillers such as NSAIDs or COX2 inhibitors, *
• Moderate pain
  • Weak opioids, or alternatively, low doses of strong opioids*
• Severe pain
  • Strong opioids

*Adjuvant medication will be prescribed at the doctor’s discretion depending on any other symptoms one has.

There are many ways to manage pain during the course of cancer treatment.

The Body

• Occupational therapy
• Physiotherapy
• Medication
• Cancer treatment
• Interventional procedures
• Non-medical therapies

Daily lives

• Spending more time with family and friends
• Discovering new hobbies
• Proactively improving quality of life in different ways

Mindfulness

• Discovering and kindling one’s spirituality
• Meditation and reflection

Moral support

• Care and attention from one’s support network
• Guidance and counselling

It is essential to consult pain specialists or oncologists before attempting the following treatments.

Cancer treatment

• Radiotherapy
  • A short-term course (1 to 10 visits) is proven to reduce at least 70% of cancer-related pain
  • Very few associated side effects
• Anti-cancer treatment
  • If the cancer responses to a specific anticancer treatment, the pain can also be alleviated.
  • For example, if a lung cancer patient has bone pain due to bone metastasis, the chemotherapy targeting the lung cancer can help to control the bone pain as well.

Invasive procedures

• Radiofrequency ablation
  • Using heat to reduce the transmission and spread of pain
  • Non-surgical procedure, only needs local anaesthesia.
• Neuromodulation
• Spinal cord stimulation

Non-medical treatment

• Physiotherapy
• Occupational therapy
• Spiritual and religious guidance
• Acupuncture

Reflection for patients

Questions can be asked by patients to themselves in reflection:

• Honesty with one’s support network
  •  “What am I still worried about that can be easily resolved by my support network?”
  • “Are there any other things that they are anaware of, but they should know?”
• “What have I learnt from reading this section of the app?”
• “Am I being proactive enough with treatments?“
• “Do I tend to endure pain? Does it make any more sense after reading this?”

Takeaway:

Below are several common misconceptions that are debunked by clinical oncologists:

1. If I feel pain, does it mean it is the end of the life for me? 

By Dr. William Foo, Specialist in Clinical Oncology:

“Absolutely not! Patients will feel pain at any stage of the treatment process, and it is the most common symptom in cancer patients. Pain can be the direct result of tumours, treatment procedures such as surgeries, chemotherapy or radiotherapy, or even be completely unrelated to tumours or cancer itself. Some types of pain go away completely after a tumour has been removed. Other times, it is when the side effects from treatment wear off. However, with some forms of long-lasting pain, this can continuously affect the patient negatively. So with that said, pain doesn’t always mean that one’s condition is taking a turn for the worse.”

2. Treating cancer is the most important, which means that pain management is not, right?

By Dr. Lam Tai Chung, Specialist in Clinical Oncology:

 “Pain management is one of the most important factors to be considered during cancer treatment, being just as high-priority as targeting the cancer itself. The sooner patients proactively seek treatment, the sooner the pain and any discomfort will be effectively managed. This has direct consequences to patients’ survival outlook, quality of life and mental health.”

3. Since I cannot avoid pain, so will simply enduring it do me any good? 

By Dr. Chan Po Chung, Specialist in Clinical Oncology:

“Endurance is considered a virtue in traditional Chinese philosophy. However, this alone does not apply to cancer patients, as it will not take them very far. In fact, there is just no need in suffering excruciating pain. Inadequate pain management will have far-reaching effects on the patient’s sleep, appetite, as well as mental and physical health. The consequences could even extend to stopping cancer treatment. Taking painkillers at the right time not only makes the patient feel better, but also allows them to maintain a good quality of life. In the long run, this could equate to effective control of the cancer itself.”

4. Should I wait until there’s pain or when it gets unbearable before taking my medication? 

By Dr. Macy Tong, Specialist in Clinical Oncology:  

“The key tenet of pain management during cancer treatment is, “Solving the problem before it even happens”. Waiting until it becomes unbearable is never the right way to manage pain properly. Taking medication in a hurry just as pain sets in reduces its overall effectiveness, leading to a common misconception that the painkillers do not work at all. In fact, doing so will actually drastically increase the risk of additional side effects.”

5. When the painkillers are not alleviating my pain, they will not work anymore, right? 

By Dr. Carmen Leung, Specialist in Clinical Oncology:

“It is a very common misconception among patients. When painkillers are prescribed properly, there is very little chance that the medication is ineffective. Patients are usually misguided after seeing just the first dose or two not delivering the desired effect, losing confidence in their prescriptions. It is noteworthy that medicines never come into effect the moment they are swallowed. However, taking long-acting medication has been proven to prevent slow reactions to painkillers.”

6. Painkillers pose many side effects. Will there be a 100% chance of addiction? 

By Dr. Lim Mei-ying, Specialist in Clinical Oncology:

"Every medication has side effects. Those of painkillers normally include tiredness, nausea, a stuffy nose, vomiting and constipation. Most of these are mild and commonly observed, so doctors can prescribe other drugs in advance to prevent them. If the patient is too responsive to side effects, the doctor can also switch to a new type of painkiller to reduce them. As seen in daily clinical practice, there are actually more cases of self-discontinuation on the part of the patient than doctors asking patients to discontinue medication. Addiction should not be a primary concern at all as every medication is tailor-prescribed to prevent this from happening.”

7. Will discussing pain with my doctor prevent them from concentrating on my cancer treatment? 

By Dr Inda Sung Soong, Specialist in Clinical Oncology:

“Us oncologists invest a great deal of attention on pain management. Patients are more than welcome to take the initiative to discuss any instance of pain with their doctor. Therefore, patients can take the initiative to share their views and perceptions of pain with the doctor. Small details such as pain intensity and situation, when and where the pain occurs as well as its impact on life can potentially be life-changing. This information will help doctors understand the extent of the pain and develop appropriate methods for relieving the pain. In addition to medication and interventional treatment options, some hospitals also provide psychological assistance and spiritual support to patients, providing a comprehensive approach to pain relief for them.”

8. I want to be as transparent as possible to my doctors and health professionals. How should I organise information for discussions about my pain?

As should be known, simply relying on memory to recount any pain you’ve suffered between check-ups is no easy task. Keeping a daily record of it allows health professionals in your support network to be updated as much as possible about your condition.

Hong Kong Society of Clinical Oncology: Pain in cancer patients in Hong Kong 2017

Facts About Cancer Pain. American Cancer Society, viewed 2019, November 27. 

Causes and types of cancer pain. Cancer Research UK, viewed 2019, November 27. 

Adrienne Santos-Longhurst (2018, November 29). Types of Pain: How to Recognize and Talk About Them. 

Caraceni A, Hanks G., et al. Use of opioid analgesics in the treatment of cancer pain: evidence-based recommendations from the EAPC. Lancet Oncol 2012;13: e58-68 

Hayden, D and Ui Dhuibhir, P. Managing Breakthrough Cancer Pain in Palliative Care. European Oncology Nursing Society (EONS) Newsletter Autumn 2010; 20-23. 

Gruener DM. (2019, November 26) New Strategies for Managing Acute Pain Episodes in patients with chronic pain. 

PAIN ASSESSMENT and MANAGEMENT Clinical Practice Guidelines. Winnipeg Regional Authority April 2012

Rao, A.A., Rao, V.N., Devi, A.S., Anil, K., Naik, V.V., & Rajesh, A. (2015). Oral Controlled Release Drug Delivery System: An Overview. IJAPCR 2015; 1(1):6-15. 

Simmonds, M A. (1999, August 1) Management of Breakthrough Pain Due to Cancer. Oncology 13(8):1103-1108,1999. 

Early History of Cancer: Origin of the word cancer. American Cancer Society, viewed 2019, November 27. 1

Hong Kong Society of Clinical Oncology: Pain management (Chinese version only)

Special thanks to Mr. Joshua Tang and Dr. Wendy Wing-Lok Chan, Department of Clinical Oncology, the University of Hong Kong for editing this article.

Last updated on 1 Nov 2021.

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