Pain Medicine · Supplementary · from Pain Medicine

Case 3: Cancer Pain Management with Multimodal Approach

Patient Presentation

Demographics: 62-year-old male retired firefighter

Chief Complaint: "The pain in my back and ribs is getting worse despite the morphine — I can barely get out of bed now."

History of Present Illness: Mr. R.C. is referred to the palliative pain service from oncology for escalating pain in the context of metastatic non-small cell lung cancer (adenocarcinoma, EGFR-negative, PD-L1 50%, stage IV). He was diagnosed 14 months ago after presenting with persistent cough and hemoptysis. Initial staging revealed a 4.2 cm right upper lobe primary with mediastinal lymphadenopathy, T3 rib involvement (right 4th and 5th ribs), and osseous metastases to T8, T11, L2, and the right ilium. He has received pembrolizumab with carboplatin/pemetrexed (4 cycles), with partial response in the primary but progression of osseous disease.

His pain is multifocal: (1) constant, deep, aching mid-thoracic back pain rated 7/10 centered at T8 and T11, worsened by movement and position changes (somatic nociceptive — bone metastases); (2) sharp, lancinating right chest wall pain at the 4th-5th ribs rated 8/10, provoked by breathing, coughing, and truncal rotation (mixed nociceptive/neuropathic — rib metastases with intercostal nerve involvement); (3) intermittent burning, shooting pain radiating from the mid-back into the bilateral lower extremities, rated 6/10 (neuropathic — epidural extension at T11 with nerve root compression).

He reports 4-5 breakthrough pain episodes daily, each lasting 15-45 minutes, often triggered by movement. His current oral morphine regimen provides approximately 40% pain relief. He has lost 8 kg in the past 3 months, has poor appetite, and his functional status has declined from ECOG 1 to ECOG 3 over 2 months.

Past Medical History:

• Non-small cell lung cancer (adenocarcinoma), stage IV with osseous metastases (diagnosed 14 months ago)
• COPD (moderate, FEV1 55% predicted)
• Occupational exposures: 30 years of firefighting with smoke, asbestos, diesel exhaust, PFAS exposure
• Hypertension
• Remote history of alcohol use disorder (sober 15 years)

Medications:

• Morphine sulfate extended-release 60 mg BID (120 mg/day)
• Morphine sulfate immediate-release 15 mg Q4H PRN breakthrough (using 4-5 doses/day)
• Dexamethasone 4 mg BID
• Pembrolizumab 200 mg IV Q3 weeks (ongoing)
• Tiotropium 18 mcg inhaled daily
• Lisinopril 10 mg daily
• Ondansetron 4 mg Q8H PRN nausea
• Docusate/senna BID
• Omeprazole 20 mg daily

Social History:

• Former smoker: 40 pack-year history (quit 5 years ago)
• Alcohol: sober 15 years (AA member)
• Married, 4 adult children (all local and supportive)
• Retired firefighter (30 years of service); strong social network through fire department
• Has advance directive in place; full code status currently but "open to discussing" hospice

Family History:

• Father: lung cancer (died age 68, smoker)
• Mother: breast cancer (survived, died age 82 of stroke)

Physical Examination

• Vital Signs: BP 108/68 mmHg, HR 92 bpm, RR 22, SpO2 91% on room air, Temp 36.9°C, BMI 22.1 kg/m² (down from 26.3)
• General: Cachectic-appearing, chronically ill male; grimaces with position changes; moderately sedated (Richmond Agitation-Sedation Scale -1)
• Pulmonary: Decreased breath sounds right upper lobe; scattered rhonchi bilaterally; tenderness to palpation over right 4th-5th ribs with palpable mass
• Spine: Point tenderness over T8 and T11 spinous processes; midline and paraspinal tenderness at T11-L2; no gibbus deformity
• Neurological:
• Lower extremities: bilateral hip flexor weakness 4/5; knee extension 4+/5 bilaterally; ankle dorsiflexion 5/5 bilaterally
• Sensory: diminished pinprick sensation in bilateral T10-L1 dermatomes; burning dysesthesia with light touch over right T4-T5 dermatomes
• Reflexes: patellar reflexes 3+ bilaterally (hyperreflexic); no clonus; Babinski equivocal on left
• Allodynia in right T4-T5 intercostal distribution
• Abdomen: Soft, mildly distended, decreased bowel sounds (opioid-related constipation)
• Functional assessment: ECOG 3; Palliative Performance Scale 40%; unable to ambulate independently; requires assistance with transfers

Workup and Results

Laboratory Studies:

Imaging/Additional Studies:

• CT chest/abdomen/pelvis: Stable right upper lobe mass (3.8 cm, decreased from 4.2 cm); new pathologic compression fracture T11 with 40% height loss; progressive lytic lesions T8, L2, right ilium; epidural soft tissue component at T11 causing moderate spinal canal narrowing but no frank cord compression
• MRI thoracolumbar spine: T11 pathologic fracture with retropulsion of fragment into ventral thecal sac; epidural tumor extension causing 50% canal compromise at T11; T8 and L2 vertebral body metastases without canal stenosis; no definitive cord signal abnormality on T2-weighted sequences
• Bone scan: Multiple areas of increased uptake: T8, T11, L2, right ilium, bilateral 4th-5th ribs; no new metastatic sites compared to prior scan
• Edmonton Symptom Assessment Scale: Pain 8/10, fatigue 8/10, nausea 4/10, depression 5/10, anxiety 6/10, drowsiness 6/10, appetite 2/10, wellbeing 3/10, constipation 7/10

Clinical Image

Illustration depicting the WHO analgesic ladder modified for cancer pain, integrated with interventional and multimodal strategies for bone metastasis pain management. Source: Educational illustration.

Diagnosis

Cancer-Related Pain Syndrome, Mixed Mechanism: Somatic Nociceptive (Bone Metastases), Neuropathic (Intercostal and Epidural Nerve Compression), with Incident/Breakthrough Pain — in the Setting of Metastatic NSCLC with Impending Spinal Cord Compression and Malignant Hypercalcemia

Key Diagnostic Criteria:

• Multifocal pain with identifiable structural causes on imaging (bone metastases, rib involvement, epidural extension)
• Three distinct pain mechanisms identified: somatic nociceptive (bone), neuropathic (nerve compression/invasion), and movement-evoked (incident) pain
• Epidural disease at T11 with early neurological signs (hyperreflexia, mild weakness) indicating impending cord compression — oncological emergency
• Hypercalcemia of malignancy (corrected calcium 11.8 mg/dL) contributing to symptom burden
• Pain inadequately controlled on 120 mg oral morphine equivalent daily with breakthrough dosing

Treatment Plan

1. Urgent interventions:

• Hypercalcemia: IV normal saline 1L bolus then 200 mL/hr; zoledronic acid 4 mg IV over 15 minutes; recheck calcium at 24 and 48 hours
• Impending cord compression: Increase dexamethasone to 10 mg IV Q6H (24-48 hours) then taper; urgent radiation oncology consultation for T11 (conventional external beam RT 30 Gy in 10 fractions or stereotactic body RT 24 Gy in 2 fractions); neurosurgery consultation for consideration of T11 decompression and stabilization if surgical candidate

1. Opioid optimization:

• Rotate from morphine to hydromorphone (incomplete cross-tolerance advantage; better in renal impairment with Cr 1.4)
• Calculate equianalgesic dose: morphine 120 mg oral/day + 60-75 mg breakthrough = ~180-195 mg/day → hydromorphone oral ~36-39 mg/day → reduce by 25% for rotation = ~28-30 mg/day → hydromorphone ER 8 mg TID with hydromorphone IR 4 mg Q3H PRN
• Rapid-onset fentanyl (buccal tablet 200 mcg) for breakthrough episodes with fast onset needed

1. Neuropathic pain adjuvants:

• Add pregabalin 75 mg BID, titrate to 150 mg BID over 2 weeks (target intercostal and radicular neuropathic pain)
• Consider lidocaine 5% patch over right chest wall (topical for intercostal allodynia)
• If neuropathic component refractory: consider ketamine infusion (sub-anesthetic, 0.1-0.3 mg/kg/hr for 24-48 hours)

1. Interventional pain management:

• Right intercostal nerve block (T4-T5) with bupivacaine and dexamethasone for chest wall pain
• If sustained benefit needed: intercostal neurolysis with phenol or cryoablation
• Consider intrathecal drug delivery system (IDDS) if pain continues to escalate (intrathecal morphine + bupivacaine ± ziconotide); patient on >200 MME/day is appropriate candidate per PACC guidelines

1. Bone-targeted therapy:

• Continue zoledronic acid 4 mg IV Q4 weeks (both hypercalcemia and skeletal events)
• Denosumab 120 mg SC Q4 weeks as alternative if renal function declines
• Palliative radiation to T8 and right ilium if pain remains refractory
• Radium-223 or samarium-153 consideration deferred (non-prostate cancer, limited data)

1. Supportive and palliative care:

• Aggressive bowel regimen: methylnaltrexone 12 mg SC every other day (opioid-induced constipation refractory to oral laxatives)
• Nutritional support: megestrol acetate 400 mg daily or consider olanzapine 2.5 mg for appetite
• Vitamin D3 50,000 IU weekly x 8 weeks then 2,000 IU daily
• Physical therapy for mobility preservation and fall prevention
• Palliative care team co-management; goals of care discussion; hospice eligibility review

1. Follow-up: 48-hour reassessment of calcium and neurological status; weekly pain reassessments during radiation course; ESAS tracking at every visit

Key Learning Points

• Cancer pain is frequently mixed-mechanism, involving nociceptive (somatic and visceral), neuropathic, and nociplastic components; each mechanism requires targeted pharmacotherapy for optimal control — a single-agent approach is rarely sufficient
• Opioid rotation is indicated when dose-limiting side effects occur or when analgesic efficacy plateaus; the equianalgesic dose calculation must include a 25-50% reduction for incomplete cross-tolerance, with careful titration
• Impending spinal cord compression is an oncological emergency; the combination of epidural disease, hyperreflexia, and emerging weakness mandates urgent high-dose corticosteroids and radiation oncology consultation within 24 hours
• Interventional techniques (nerve blocks, neuraxial analgesia, intrathecal pumps) should be considered early in cancer pain management, not as a last resort; IDDS can provide superior analgesia with lower systemic opioid side effects
• Hypercalcemia of malignancy occurs in up to 30% of advanced cancers and contributes to pain, confusion, constipation, and fatigue; IV hydration and bisphosphonates are first-line treatment and may independently improve pain control

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