Cancer Pain Management

Last updated: January 2025 | Medical Reviewer: Oncol.net Editorial Board

Overview

Pain affects 50-70% of cancer patients at some point during their illness. While pain is one of the most feared aspects of cancer, it is also one of the most treatable symptoms. With appropriate treatment using the WHO Pain Ladder and modern pain management strategies, the vast majority of cancer patients can achieve good pain control that allows them to maintain quality of life and continue their daily activities.

Cancer pain is not a single entity - it has multiple causes, varies in intensity and character, and requires individualized treatment. Understanding the source and type of your pain helps your healthcare team create the most effective treatment plan for you.

Types of Cancer-Related Pain

1. Cancer Pain (Directly from the Tumor)

Pain caused by the cancer itself as it grows and affects surrounding tissues:

• Bone pain: Tumor growing in or metastasizing to bone
  • Character: Deep, aching, worse with movement or weight-bearing
  • Common in: Breast, prostate, lung cancer (common sites of bone metastases)
  • May cause: Fractures, nerve compression
• Visceral pain: Tumor pressing on or invading internal organs
  • Character: Deep, dull, aching, poorly localized, cramping
  • Common in: Liver, pancreatic, ovarian, colon cancers
  • May cause: Organ distention, obstruction, inflammation
• Nerve pain (neuropathic): Tumor compressing or invading nerves
  • Character: Burning, shooting, electric-shock-like, tingling, numbness
  • Common in: Spinal cord compression, nerve infiltration, plexus involvement
  • Examples: Brachial plexus (lung cancer), lumbosacral plexus (pelvic cancers)
• Soft tissue pain: Tumor stretching or invading muscles, skin, connective tissue
  • Character: Sharp, aching, throbbing
  • May worsen with: Movement, pressure, inflammation
• Increased intracranial pressure: Brain tumors or brain metastases
  • Character: Headache, worse in morning, with coughing/straining
  • Associated symptoms: Nausea, vomiting, vision changes

2. Treatment-Related Pain

Pain caused by cancer treatments themselves:

• Post-surgical pain:
  • Acute pain immediately after surgery
  • Chronic post-surgical pain (lasting >3 months)
  • Phantom limb pain after amputation
  • Post-mastectomy pain syndrome
  • Post-thoracotomy pain syndrome
• Chemotherapy-induced pain:
  • Peripheral neuropathy (numbness, tingling, burning in hands/feet)
  • Mucositis (painful mouth and throat sores)
  • Arthralgias and myalgias (joint and muscle pain)
  • Abdominal cramping
  • Headaches
• Radiation-induced pain:
  • Acute radiation dermatitis (skin pain, burning)
  • Radiation mucositis
  • Radiation proctitis or cystitis
  • Late effects: Fibrosis, secondary nerve damage, bone necrosis
• Immunotherapy-related pain:
  • Inflammatory arthritis
  • Muscle pain
  • Neuropathy (less common than with chemo)

3. Procedure-Related Pain

Pain from diagnostic or therapeutic procedures:

• Biopsies (bone marrow, tissue)
• Port access or IV placement
• Blood draws
• Lumbar punctures
• Bone marrow aspirations
• Thoracentesis or paracentesis (fluid drainage)

Pain Assessment

Describing Your Pain

Effective pain management starts with accurate pain assessment. Your healthcare team needs detailed information about your pain to treat it appropriately. Be prepared to describe:

Pain Intensity (0-10 Scale)

• 0: No pain
• 1-3: Mild pain (annoying but doesn't interfere with activities)
• 4-6: Moderate pain (interferes with concentration and activities)
• 7-9: Severe pain (dominates your thoughts, prevents most activities)
• 10: Worst pain imaginable (unbearable, requires emergency care)

Pain Quality (What Does It Feel Like?)

• Sharp, stabbing, knife-like
• Dull, aching, throbbing
• Burning, searing, hot
• Shooting, electric-shock-like
• Cramping, squeezing
• Tingling, pins-and-needles
• Numbness
• Pressure, heaviness

Pain Location

• Where exactly is the pain?
• Does it radiate (spread) to other areas?
• Is it in one spot or multiple locations?

Pain Timing and Pattern

• Constant (continuous): Present all the time
• Intermittent: Comes and goes
• Breakthrough: Sudden flares of pain despite baseline medication
• Movement-related: Occurs with specific activities
• Time of day: Worse in morning, evening, or night

What Makes It Better or Worse?

• Movement, position, activity
• Rest or sleep
• Eating or bowel movements
• Medications taken
• Heat, cold, massage

Impact on Function and Quality of Life

• Sleep disturbance
• Ability to work or do daily activities
• Appetite and eating
• Mood (anxiety, depression)
• Relationships and social activities

The WHO Pain Ladder

The World Health Organization (WHO) Pain Ladder is the gold standard framework for cancer pain management. It provides a step-wise approach to treating pain based on severity, starting with simple medications and progressing to stronger options as needed.

Important Principles of Opioid Use

• "By the mouth": Oral route preferred when possible (convenient, non-invasive)
• "By the clock": Around-the-clock dosing for continuous pain (not "as needed" only)
• "By the ladder": Start at appropriate step based on pain severity
• "For the individual": Titrate dose to pain relief, no standard maximum dose
• "Attention to detail": Anticipate and manage side effects proactively

Breakthrough Pain

What Is Breakthrough Pain?

Breakthrough pain is a transient flare of pain that occurs despite around-the-clock pain medication. It affects 40-80% of cancer patients taking opioids for baseline pain. Breakthrough pain can be:

• Spontaneous (idiopathic): Unpredictable, no clear trigger
• Incident pain: Predictable, related to movement or activity (walking, coughing, etc.)
• End-of-dose failure: Pain returns before next scheduled dose

Managing Breakthrough Pain

Short-Acting Opioid "Rescue Doses":

• Typically 10-20% of total daily opioid dose given as single breakthrough dose
• Use immediate-release formulation of same or different opioid
• Can be taken every 1-2 hours as needed
• Examples:
  • If on 60 mg morphine ER twice daily (120 mg/day total), breakthrough dose = 10-20 mg immediate release morphine
  • If on 50 mcg/hour fentanyl patch, breakthrough dose = morphine 10-15 mg or oxycodone 7.5-10 mg

Rapid-Onset Fentanyl Products:

• Work within 10-15 minutes for breakthrough pain
• Forms: Buccal tablet, sublingual spray/tablet, nasal spray
• Reserved for patients already on around-the-clock opioids (opioid-tolerant)
• Must be individually titrated - not directly converted from other opioids

For Predictable Incident Pain:

• Take breakthrough medication 30-60 minutes before anticipated painful activity
• Examples: Before dressing changes, physical therapy, walking

When to Adjust Baseline Medication:

• If using >3-4 breakthrough doses per day regularly
• Calculate total daily opioid use (baseline + all breakthrough doses)
• Increase baseline long-acting opioid to cover most pain
• Recalculate new breakthrough dose (10-20% of new total daily dose)

Adjuvant Medications

Adjuvant (co-analgesic) medications are drugs with primary indications other than pain but can enhance pain relief or treat specific pain types. They are used at every step of the WHO ladder.

For Neuropathic Pain

Neuropathic pain (burning, shooting, tingling) often responds poorly to opioids alone and benefits from adjuvants:

Gabapentin (Neurontin):

• First-line for neuropathic pain
• Start: 100-300 mg at bedtime, increase gradually
• Target: 300-600 mg three times daily (900-1800 mg/day), can go higher (up to 3600 mg/day)
• Mechanism: Binds calcium channels on nerves
• Benefits: Well-tolerated, no organ toxicity
• Side effects: Drowsiness (often improves), dizziness, edema
• Tip: Take largest dose at bedtime if sedating

Pregabalin (Lyrica):

• Similar to gabapentin but more potent
• Dose: 75-150 mg twice daily (can increase to 300 mg twice daily)
• Benefits: Twice-daily dosing, faster titration than gabapentin
• Side effects: Similar to gabapentin
• Note: More expensive than gabapentin

Tricyclic Antidepressants:

• Amitriptyline (Elavil): 10-75 mg at bedtime
• Nortriptyline (Pamelor): 10-75 mg at bedtime (fewer side effects than amitriptyline)
• Desipramine: 10-75 mg at bedtime
• Mechanism: Increase norepinephrine and serotonin (modulate pain pathways)
• Benefits: Also help sleep, depression
• Side effects: Dry mouth, constipation, drowsiness, urinary retention, weight gain
• Caution: Heart rhythm effects, avoid in elderly or heart disease

SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors):

• Duloxetine (Cymbalta): 30-60 mg daily (FDA approved for neuropathic pain)
• Venlafaxine (Effexor): 75-225 mg daily
• Benefits: Also treat depression, anxiety; better tolerated than tricyclics

For Bone Pain

Corticosteroids (Dexamethasone, Prednisone):

• Reduce inflammation and swelling around tumors
• Especially effective for bone pain, spinal cord compression, increased intracranial pressure
• Dose: Dexamethasone 4-8 mg daily or twice daily
• Benefits: Also improve appetite, energy, nausea
• Side effects: Insomnia, mood changes, elevated blood sugar, increased infection risk, stomach upset
• Note: Usually not for long-term use due to side effects

Bisphosphonates (for bone metastases):

• Zoledronic acid (Zometa), pamidronate (Aredia)
• Reduce bone destruction and pain from metastases
• Given IV every 3-4 weeks
• Benefits: Prevent fractures, reduce pain, lower calcium levels
• Caution: Kidney function monitoring, rare jaw osteonecrosis (see dentist before starting)

Denosumab (Xgeva):

• Alternative to bisphosphonates for bone metastases
• Subcutaneous injection monthly
• Can be used with kidney disease (unlike bisphosphonates)

For Muscle Spasms and Cramping

• Baclofen: 5-20 mg three times daily
• Cyclobenzaprine (Flexeril): 5-10 mg three times daily
• Tizanidine (Zanaflex): 2-8 mg every 6-8 hours
• Note: All cause sedation; use with caution

Managing Opioid Side Effects

While opioids are essential for cancer pain management, they do cause side effects. Many can be anticipated, prevented, or managed effectively. Do not let fear of side effects prevent you from achieving adequate pain control.

Constipation (Nearly Universal)

Most common and persistent opioid side effect - occurs in >90% of patients and does NOT improve with time.

Prevention is Key:

• Start bowel regimen at the same time as starting opioids (don't wait)
• Standard regimen: Stool softener (docusate 100-200 mg twice daily) PLUS stimulant laxative (senna 2 tablets at bedtime, or bisacodyl 1-2 tablets at bedtime)
• Goal: Bowel movement at least every 2-3 days
• Increase laxatives aggressively if no bowel movement for 2-3 days

Additional Options:

• Polyethylene glycol (MiraLAX): 17 grams daily in liquid (osmotic laxative)
• Lactulose or sorbitol: 15-30 mL daily (osmotic laxative)
• Magnesium citrate: For more severe constipation
• Enemas or suppositories: If oral regimen insufficient
• Methylnaltrexone (Relistor) or naloxegol (Movantik): Prescription medications that block opioid effects on gut without affecting pain relief

Lifestyle Measures:

• Increase fluid intake (8-10 glasses water daily)
• Increase fiber (fruits, vegetables, whole grains) if able to eat
• Stay as active as possible
• Establish regular toilet routine

Nausea (Common Initially, Usually Improves)

• Occurs in 10-40% of patients starting opioids
• Usually improves within 5-7 days as tolerance develops
• Prevention/Treatment:
  • Take opioids with food (unless specific instructions otherwise)
  • Ondansetron (Zofran) 4-8 mg every 8 hours as needed
  • Metoclopramide (Reglan) 10 mg before meals and bedtime
  • Prochlorperazine (Compazine) 10 mg every 6-8 hours
  • Consider switching to different opioid if severe and persistent

Drowsiness and Sedation (Common Initially, Usually Improves)

• Common when starting opioids or increasing dose
• Usually improves within 3-7 days as tolerance develops
• If persistent:
  • Review all medications - many cause sedation (gabapentin, muscle relaxants, sleep aids)
  • Consider lower doses more frequently instead of higher doses less often
  • Consider opioid rotation (switching to different opioid)
  • Stimulants may help: Methylphenidate (Ritalin) 5-10 mg morning and noon, modafinil (Provigil) 100-200 mg morning
• Safety: Do not drive or operate machinery if drowsy

Respiratory Depression (Very Rare at Appropriate Doses)

• Most feared side effect but actually rare when opioids properly prescribed and titrated
• Tolerance develops quickly to respiratory depressant effects
• Risk factors: Opioid-naive patients receiving high initial doses, rapid IV administration, combining with benzodiazepines or alcohol, severe kidney or liver disease
• Signs: Respiratory rate <8 breaths/minute, shallow breathing, difficulty arousing
• If suspected: Call 911, give naloxone (Narcan) if available
• Important: Pain itself is a respiratory stimulant; patients on stable opioid doses for pain rarely develop respiratory depression

Other Side Effects

• Itching: Antihistamines (diphenhydramine, hydroxyzine), switch opioids if severe
• Confusion or hallucinations: More common in elderly; dose reduction or opioid switch needed
• Myoclonus (muscle jerking): Sign of opioid toxicity; dose reduction or opioid rotation
• Urinary retention: More common in men with prostate issues; may need catheterization

Addressing Addiction Concerns

Fear of addiction prevents many cancer patients from taking adequate pain medication. It is critical to understand the difference between physical dependence, tolerance, and addiction.

Important Definitions

Physical Dependence (Normal and Expected):

• The body adapts to the presence of opioids
• Stopping suddenly causes withdrawal symptoms (sweating, agitation, nausea, pain, anxiety)
• This is a NORMAL physiological response, not addiction
• Occurs with many medications (steroids, blood pressure medications, antidepressants)
• Managed by gradually tapering dose when pain improves - not stopping abruptly

Tolerance (Common, Manageable):

• Over time, higher doses needed to achieve same pain relief
• This is normal pharmacology, not addiction
• Managed by dose increases or opioid rotation
• Tolerance to side effects also develops (drowsiness, nausea) - a benefit
• No ceiling dose for opioids - dose increased as needed for pain

Addiction (Psychological Dependence - Rare in Cancer Patients):

• A complex brain disease characterized by compulsive drug seeking despite harm
• Psychological craving unrelated to pain relief
• Loss of control over use
• Continued use despite physical, social, psychological harm
• Risk factors: Personal or family history of substance abuse, psychiatric disorders
• Rate in cancer patients: <1% in those without prior substance abuse

Concerns About "Saving" Medications for Later

Some patients worry about taking strong pain medications "too early" because they might need them more later. This thinking is counterproductive:

• Pain is easier to control if treated early, before it becomes severe
• There is NO maximum dose of opioids - they can always be increased
• Uncontrolled pain is harmful - causes stress, weakens immune system, prevents healing
• Suffering needlessly now doesn't preserve your ability to control pain later

Safe Opioid Use

• Take medications exactly as prescribed
• Store medications securely away from children and visitors
• Never share your pain medications with others
• Do not combine with alcohol or illicit drugs
• Inform all healthcare providers about opioid use (drug interactions)
• Use one pharmacy for all prescriptions (interaction screening)
• Dispose of unused medications properly (pharmacy take-back programs)
• Keep naloxone (Narcan) available if at higher risk (available without prescription in most states)

Interventional and Non-Drug Approaches

Radiation Therapy for Pain

Highly effective for certain pain types, especially bone pain:

• Palliative radiation for bone metastases:
  • 70-90% of patients experience pain relief
  • Can be single dose or short course (1-10 treatments)
  • Pain relief may take 1-2 weeks to develop
  • Can prevent fractures and spinal cord compression
• Stereotactic body radiation therapy (SBRT): High-precision radiation for spinal or other bone metastases
• Radiopharmaceuticals:
  • Strontium-89, samarium-153, radium-223
  • IV injection targets multiple bone metastases
  • Useful when pain at multiple sites

Nerve Blocks and Interventional Procedures

Performed by pain specialists or anesthesiologists:

• Celiac plexus block: For pancreatic cancer or upper abdominal pain
  • Injection of anesthetic/alcohol near celiac plexus nerves
  • Can provide weeks to months of pain relief
  • 70-90% effective for pancreatic cancer pain
• Epidural or intrathecal drug delivery:
  • Medications delivered directly into spinal fluid
  • Allows much lower doses with fewer side effects
  • Implanted pumps for long-term use
  • For severe pain not controlled with oral medications
• Nerve blocks: Local anesthetic injections near specific nerves
• Neurolytic procedures: Destruction of nerves causing pain (radiofrequency ablation, cryoablation)
• Vertebroplasty/kyphoplasty: Cement injection for painful vertebral compression fractures

Physical Approaches

• Heat therapy:
  • Heating pads, warm baths, warm compresses
  • Good for muscle pain, stiffness
  • Caution: Not on areas receiving radiation, watch for burns if neuropathy
• Cold therapy:
  • Ice packs, cold compresses
  • Good for acute pain, inflammation, swelling
  • 20 minutes on, 20 minutes off
• Massage:
  • Gentle massage can reduce pain and promote relaxation
  • Avoid deep pressure over tumor sites or areas with bone metastases
  • Seek massage therapist trained in oncology massage
• Physical therapy:
  • Gentle exercises to maintain strength and mobility
  • Stretching to reduce stiffness
  • TENS (transcutaneous electrical nerve stimulation)
• Acupuncture:
  • May help some types of pain
  • Safe when performed by trained practitioners
  • Caution: Avoid if low blood counts (infection/bleeding risk)

Mind-Body Approaches

These do not replace medications but can enhance pain control:

• Relaxation techniques:
  • Deep breathing exercises
  • Progressive muscle relaxation
  • Guided imagery
• Meditation and mindfulness: Help change pain perception and reduce suffering
• Music therapy: Distraction and relaxation
• Hypnosis: Can reduce pain perception in some patients
• Cognitive behavioral therapy (CBT): Addresses thoughts and behaviors related to pain
• Distraction: Engaging activities, hobbies, social interaction

Common Myths About Cancer Pain

When to Call Your Healthcare Team

Schedule an Appointment For:

• Pain not adequately controlled with current regimen (most of the time >5/10)
• Using breakthrough pain medication >3-4 times per day regularly
• Side effects interfering with quality of life (constipation, persistent drowsiness, nausea)
• Pain pattern changing (worse at different times, different quality)
• Pain interfering with daily activities, sleep, appetite
• Interest in complementary approaches, nerve blocks, or other interventions
• Concerns about medications, addiction, or side effects
• Running low on medications (don't wait until you run out)
• Referral to pain specialist or palliative care needed

Keep a Pain Diary

Tracking your pain helps your healthcare team optimize your treatment:

• Pain intensity several times daily (0-10 scale)
• Location and quality of pain
• Times of day pain is worse/better
• Activities that increase or decrease pain
• Medications taken and timing
• Breakthrough doses used and effectiveness
• Side effects experienced
• Impact on sleep, mood, activities

The Role of Palliative Care

Palliative care specialists are experts in pain and symptom management for serious illnesses. Palliative care is NOT the same as hospice and does NOT mean giving up on cancer treatment.

What Is Palliative Care?

• Specialized medical care focused on providing relief from symptoms and improving quality of life
• Can be provided alongside curative cancer treatment at any stage of disease
• Provided by team including physicians, nurses, social workers, chaplains
• Focuses on whole person: physical, emotional, spiritual, practical needs

When to Consider Palliative Care Consultation

• Complex or difficult-to-control pain
• Multiple distressing symptoms
• Need for clarification about goals of care
• Difficulty coping emotionally with diagnosis
• Need for coordination between multiple specialists
• Advanced cancer or serious prognosis

Benefits of Palliative Care

• Improved pain and symptom control
• Better quality of life
• Reduced hospital admissions
• Support for emotional and spiritual needs
• Assistance with difficult decisions
• Some studies show improved survival when palliative care integrated early

Frequently Asked Questions

How quickly should pain medication work?

This depends on the type of medication and formulation. Immediate-release opioids (morphine IR, oxycodone IR) typically work within 30-60 minutes and peak at 1-2 hours. Extended-release formulations take longer to reach steady state (12-24 hours) but provide longer-lasting relief. Adjuvant medications like gabapentin or antidepressants may take 1-2 weeks to show full effect. If breakthrough pain medication isn't working within an hour, contact your team.

Is it safe to take pain medication every day long-term?

Yes, absolutely. Opioids and other pain medications can be safely taken long-term when prescribed and monitored appropriately. There is no arbitrary time limit. The goal is pain control and quality of life. Your healthcare team will regularly assess your pain and adjust medications as needed. Long-term side effects are manageable, and benefits of pain control far outweigh risks.

Can I take ibuprofen or Tylenol along with opioids?

Yes, in most cases. Non-opioid pain medications (acetaminophen, NSAIDs) work through different mechanisms than opioids and can provide additive pain relief. This is the principle of the WHO ladder. However, check with your team first: NSAIDs should be avoided if you have low platelets (bleeding risk) or kidney disease. Acetaminophen has a daily maximum dose (3000-4000 mg/day including any combination products). Always coordinate with your healthcare providers.

What if I miss a dose of my long-acting pain medication?

Take it as soon as you remember, unless it's almost time for your next dose. Don't double up doses. If you miss more than one dose or are unsure what to do, contact your healthcare team. Missing doses can lead to breakthrough pain and withdrawal symptoms. Consider setting alarms or using a pillbox to help remember medications.

Can I drink alcohol while taking pain medications?

No, you should avoid alcohol while taking opioid pain medications. Alcohol increases the sedative effects of opioids and significantly increases risk of respiratory depression, falls, and other dangerous side effects. If you have questions about alcohol use, discuss honestly with your healthcare team.

Why does my doctor keep asking about my bowel movements?

Constipation is the most common and persistent side effect of opioid pain medications, affecting more than 90% of patients. Unlike other side effects, tolerance does NOT develop to constipation - it remains a problem as long as you take opioids. Severe constipation can be dangerous (bowel obstruction) and very uncomfortable. Proactive bowel management is essential for anyone taking opioids regularly.

What is opioid rotation and when is it used?

Opioid rotation is switching from one opioid to a different opioid. This is done when: (1) Side effects are limiting dose increases needed for pain control, (2) Pain is not adequately controlled despite high doses, (3) Patient develops tolerance. Different opioids work slightly differently, and some patients tolerate one better than another. Your doctor will calculate an equivalent dose of the new opioid, usually starting at 50-75% of the calculated dose to be safe.

Will I be able to drive while taking pain medications?

This depends on how the medication affects you. When starting opioids or increasing doses, do NOT drive due to drowsiness risk. Once you're on a stable dose and no longer experiencing sedation, many patients can drive safely. However, this is an individual decision that should be discussed with your healthcare provider. Some states have laws about driving while taking controlled substances. If you feel drowsy or impaired in any way, do not drive.

What should I do with leftover pain medications?

Do NOT keep unused opioid medications "just in case" or share them with family/friends. Unused opioids should be disposed of promptly through medication take-back programs (many pharmacies offer this) or following FDA guidelines for disposal (mixing with unpleasant substance like coffee grounds in sealed bag and throwing in trash, or using drug deactivation pouches). Do not flush down toilet unless label specifically instructs to do so.

My pain is controlled but I'm not happy with the side effects. What can I do?

You don't have to choose between pain control and intolerable side effects. Multiple options are available: (1) Aggressive treatment of side effects (bowel regimen for constipation, antiemetics for nausea), (2) Opioid rotation to a different opioid with better side effect profile for you, (3) Addition of adjuvant medications to reduce opioid dose needed, (4) Interventional procedures (nerve blocks) that may reduce medication requirements, (5) Non-pharmacological approaches. Talk to your healthcare team - solutions are available.

Sources and References

• World Health Organization. WHO Guidelines for the Pharmacological and Radiotherapeutic Management of Cancer Pain in Adults and Adolescents. 2018.
• National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines: Adult Cancer Pain. Version 1.2025.
• American Society of Clinical Oncology (ASCO). Management of Chronic Pain in Survivors of Adult Cancers: Guideline. 2024.
• Paice JA, et al. Management of Chronic Pain in Survivors of Adult Cancers: ASCO Clinical Practice Guideline. J Clin Oncol. 2016.
• Swarm RA, et al. Adult Cancer Pain, Version 3.2019, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw. 2019.
• Fallon M, et al. Management of Cancer Pain in Adult Patients: ESMO Clinical Practice Guidelines. Ann Oncol. 2018.
• Portenoy RK. Treatment of Cancer Pain. Lancet. 2011.