ADVANCED PAIN MANAGEMENT IN CANCER PATIENTS PADMA GULUR MD DIRECTOR, PAIN SERVICES, UCI HEALTH PROFESSOR, UNIVERSITY OF CALIFORNIA DISCLOSURES NONE OBJECTIVES • Unique considerations in cancer pain • Advanced Interventional strategies Neurolytic blocks Intrathecal drug delivery systems Neuromodulation CANCER PAIN Tom Zetterstrom. Coast Oak. CANCER PAIN - CONSIDERATIONS • Related to tumor involvement • • Accounts for 78% of pain problems in inpatient cancer population and 62% of outpatient cancer population Metastatic bone disease, hollow viscous involvement and nerve compression or infiltration are most common causes • Pain associated with cancer therapy • 19% of pain problems in inpatient population and 25% in outpatient population • Pain unrelated to cancer or therapy • Approx. 3% of inpatients have pain unrelated to their cancer and 10% in outpatient population • Generalized pain in a dying cancer patient Foley KM. Acta Anaesthesiol Scand 1982;74:91-6. Twycross RG. Pain 1982;14:303-10. PAIN IN CANCER of cancer patients undergoing treatment for their cancer and nearly 80-90% of patients with advanced disease suffer from moderate to severe pain. 30-55% THERAPEUTIC STRATEGY FOR CANCER PAIN •Pharmacotherapy •Non-pharmacological Modalities • Non-opioid analgesics • • NSAIDs Acetaminophen • • • • • • Codeine Morphine Oxycodone Fentanyl Hydromorphone Methadone • • • • • • • Opioid analgesics • Adjuvant analgesics • Anticonvulsants • Antidepressants • Local anesthetic agents • GABA agonists • NMDA antagonists • Others 14% of Cancer patients do not achieve good pain relief with acceptable side-effects even when treated by experts. Meuser T. et al., Pain, 2001 Cognitive behavioral interventions Massage, Physical Therapy Acupuncture Radiation Therapy Surgery Interventional procedures COMMON CONCERNS WITH INTERVENTIONS IN CANCER PATIENTS • Should we put patients through an “intervention”? • “Too early” or “too sick” phenomena • Sick patient population: immunosuppressed, coagulopathic, concerns with positioning • Access and follow up with interventionalists NEUROLYTIC BLOCKS FOR CANCER PAIN OVERVIEW OF NEUROLYTIC BLOCKADE ~8% cancer pain patients may need peripheral nerve block Intentional injury to a nerve/plexus: • Chemical* (alcohol or phenol) • Surgical Two Types: • Peripheral (intercostal, extremity) • Autonomic (celiac, superior hypogastric plexus) Zech et al. Validation of World Health Organization Guidelines for Cancer Pain Relief: a 10 year prospective study. Pain 1995; 63:65-76. 10 OVERVIEW OF NEUROLYTIC BLOCKADE • • “Block” vs “Neurolysis” • Effects fade: • Progression of tumor • Nerve regeneration Neurolytic effects typically last 3-6 months 11 CELIAC PLEXUS BLOCKADE CELIAC PLEXUS :UPPER ABDOMINAL STRUCTURES CP innervates: • • Pancreas • • Liver/Hepatobiliary Tree Distal Esophagus to Tranverse Colon Adrenals, Kidneys & Proximal Ureters • Mesentery Copyright Mayo Clinic, 2005 13 CELIAC PLEXUS NEUROLYSIS : TECHNIQUE Percutaneous: Fluoro/CT 1) Radio contrast dye is used to confirm placement of needle 2) Diagnostic block with local anesthetic 3) Injection of neurolytic agent Endoscopic by GI 14 “TRANSCRURAL” VS. “RETROCRURAL” Brown: Atlas of Regional Anesthesia, 3rd ed., 2006 Saunders CELIAC PLEXUS BLOCK PROVIDES EFFECTIVE ANALGESIA • Effective analgesia • Decreased opioid consumption and side effects Eisenberg et al. Neurolytic Celiac Plexus Block for Treatment of Cancer Pain: A Meta-Analysis. Anesthesia and Analgesia 1995; 80: 290-295. 16 PERCUTANEOUS CPN SERIOUS SIDE EFFECTS & ADVERSE EVENTS ARE RARE • Review of 2700 CPB/CPN in UK: • ~ 0.1% risk of paraplegia Eisenberg et al. Neurolytic Celiac Plexus Block for Treatment of Cancer Pain: A Meta-Analysis. Anesthesia and Analgesia 1995; 80: 290-295. Yan, B and Myers, R. Neurolytic Celiac Plexus Block for Pain Control in Unresectable Pancreatic Cancer. American Journal of Gastroenterology 2007; 102: 430-438) *Davies et al. Incidence of major complications of neurolytic coeliac plexus block. Journal of Royal Soc Med 1993; 86 (5): 264-6. 17 SUPERIOR HYPOGASTRIC PLEXUS BLOCKADE SUPERIOR HYPOGASTRIC PLEXUS : LOWER ABDOMEN/PELVIC ORGANS Anterior to sacral promontory at L5-S1 Innervates: • Descending Colon to Rectum • Bladder/Prostate/Gonads • Uterus/Vaginal Fundus • Some Input from Perineum/Anus 19 SUPERIOR HYPOGASTRIC PLEXUS BLOCK 1) Needles advanced anterior to L5/S1 – – Bilateral Unilateral Transdiscal 2) Radio contrast dye is used to confirm placement of needle 3) Diagnostic block with local anesthetic or Neurolytic block with alcohol or phenol 20 SHP NEUROLYSIS EFFICACY Plancarte et al, Reg Anesth 1997 • • Prospective Study: 227 patients w/ Gyn/GU/Colorectal CA • Diagnostic Block --> Bilateral SHPN Refractory pain or opioid side effects 21 SHP NEUROLYSIS EFFICACY All 227 pts w/ >7/10 pre-block • • 159 (70%) pts responded to diagnostic block 115 (51%) pts underwent SHPN w/ pain < 4/10 (16 of these required 2nd block for this effect) • 43% decrease in opioid consumption • No additional blocks at 3 months • No complications related to procedure *Poorer results in pts w/ extensive RP disease 22 MULTI-PLEXUS BLOCKADE: ? MORE EFFECTIVE IN PATIENTS W/ DIFFUSE TUMOR BURDEN • Prospective Study of 35 pts with extensive abdominal or pelvic CA w/ uncontrolled pain • Underwent combination of CPB, SHPB and Inferior Mesenteric plexus block, most w/ Transdiscal Approach • Pain scores fell from 8.8 to 2.3 over first 3 months or until death • Morphine consumption fell from 96+/-29 to 31 +/- 10 at 1 month • No Serious complications Kitoh T, Tanaka S, Ono K, et al. Combined neurolytic block of celiac, inferior mesenteric and superior hypogastric plexuses for incapacitating abdominaland/or pelvic cancer pain. J Anesth 2005; 19:328–332. 23 GANGLION IMPAR BLOCK 24 GANGLION IMPAR • Aka “Ganglion of Walther” • Sits just anterior to sacrococcygeal junction • Provides Innervation to: • Perineum* • Distal Rectum/Anus • Distal Urethra • Distal 1/3 Vagina • Vulva 25 GANGLION IMPAR NEUROLYSIS • Trans-Sacrococcygeal Approach • • Neurolysis Cryoablation (described) 26 GANGLION IMPAR NEUROLYSIS OUTCOMES • Limited to multiple small prospective studies only • eg, Plancarte et al, Anesthesiology 1990 • • • • • • 16 pts (9 w/ cervical, 1 endometrial) Rectal/perineal/vaginal pain 8 pts w/ complete relief Remainder w/ 60-90% relief Follow-up up to 120 days or death No complications reported from this technique in literature 27 SPINAL DRUG DELIVERY FOR REFRACTORY PAIN IN CANCER PATIENTS EVIDENCE IDDS OUTCOMES Clinical Success and Failure Pain and Toxicity Both Reduced by ≥ 20% Neither Reduced by ≥ 20% CMM 37.5% 23.6% IDDS 57.7% 11.3% Smith TJ et al. Journal of Clinical Oncology, October, 2002 IDDS AND SURVIVAL RESULTS AND CONCLUSION • Results • • 85% IDDS vs 70% CMM (p=.05) achieved clinical success • IDDS pts more often achieved >20% reduction in VAS and toxicity • Mean VAS reduction 52% IDDS vs 39% CMM (p=.055) • Mean Toxicity reduction 50% IDDS vs 17% CMM (p=.04) • Survival IDDS 54% alive at 6m vs 37% CMM (p=.06) Conclusion • “IDDSs improved clinical success in pain control, reduced pain, significantly relieved common drug toxicities, and improved survival in patients with refractory cancer pain” INDICATIONS • Unacceptable side effects from medical management • Uncontrolled pain with medical management CONTRA-INDICATIONS • Active infection • Obstruction to CSF flow • Mechanical barriers • < 3 month anticipated survival for implanted pump TRIAL • No consensus protocol • Bolus injection vs Continuous infusion • Epidural vs Intrathecal • Continuous intrathecal is most commonly used • Most closely simulates infusion via implanted pump EXTERNAL CATHETER External Catheter - Tunneled subcutaneously & remain external to the body - 3-4 weeks with reduced infection risk SUBCUTANEOUS PORT IMPLANTABLE INFUSION PUMP Catheter: - Tunneled under the skin - Attached to the pump Pump: - Implanted in a subcutaneous pocket in the abdomen 2 types of pump - Constant flow rate - Multiple flow rate, Programmable IMPLANTABLE PUMPS VS EXTERNAL CATHETERS Disadvantages Advantages ↓ risk of infection Fully independent of external devices Little maintenance Infrequent refill High initial cost • Opioid conversion by route is Morphine • • PO 300mg IV 100mg Epidural 10mg Intrathecal 1 mg Intrathecal Morphine 3mg/day – Opioid equivalence? On about 12.5mg IV Morphine per hour or about 2.5mg per hour of IV Dilaudid (if we use 5:1 M:HM) MORPHINE • One of 2 FDA approved IT drugs • First line drug • Opioids act at the substantia gelatinosa of • Produce dose-dependent analgesia the dorsal horn of the spinal cord • HPLC of morphine (with bupivacaine and clonidine) stored in SynchroMed pump at 37o for 90 days was 96% intact MORPHINE Paice et al (1999) • • • 429 patients ,Cancer and non-cancer After one year mean morphine dose of 14.2mg/d for cancer pts (9.2mg/d for non-cancer) Cancer patients required higher initial doses and less escalation then non-cancer pain Wallace and Yaksh (2000) reviewed 20 studies of IT morphine • • Cancer and Non-cancer Pain relief varied widely from minimal to ≥70% reporting excellent relief Bennett et al (2000) reviewed 61 studies covering >2000 pts from ’78-’99, including 3 prospective studies • • • Cancer and non-cancer 34/61 studies reported >50% pain relief Wide variations in IT doses of morphine, patient selection, etc. among studies MORPHINE • Catheter-tip granuloma • Dependent on concentration, not dose (in dog studies) • Max recommended concentration 20mg/ml ZICONITIDE (PRIALT): GOOD POTENTIAL, BUT SIDE EFFECTS LIMIT USE • Synthetic peptide derived from the venom of the marine snail Conus magus. • IT Nonopioid blocks Ca channels in spinal cord to inhibit afferent pain signal • FDA approved for refractory chronic pain • Staats et al RCT vs Placebo for Refractory Cancer/AIDS Pain in JAMA 2004* • High rate of cognitive impairment and psychiatric changes with dose escalation limit use Zuurmond et al. New aspects in performing interventional techniques for chronic pain. Current Opinion in Supportive and Palliative Care 2007; 1:132– 136.Christo, P and Mazloomdoost, D. Interventional Treatments for Cancer Pain. Ann. NY Acad. Sci. 2008; 1138:299-328. HYDROMORPHONE • Semi-synthetic hydrogenated ketone of • Activates mu, delta, and kappa • More lipid soluble then morphine • Less active metabolites • Smaller supraspinal distribution morphine FENTANYL • 100x more lipid soluble than morphine • Activates fewer receptors than morphine to achieve equivalent analgesic effect • No studies on long term safety of IT fentanyl SUFENTANIL • 1000x greater octanol:water partition coeffecient than morphine • Rapid clearance from CSF with resorption into circulatory system • Less drug tolerance than morphine METHADONE • Racemic mixture • D – isomer has NMDA antagonist activity • Mironer et al (2001) • • • • Prospective study 24 pts Failed previous IT trials 13/24 reported some level of pain reduction MEPERIDINE • Vranken et al (2005) • • • • • Prosective study 10 pts IT meperidine +/- clonidine Significantly decreased intractable neuropathic cancer pain Rapid increase in normeperidine conc 3 weeks after start BUPIVACAINE • Multiple studies report improved pain relief to IT mixture Most are uncontrolled and not randomized • • Mironer et al (2002) • • • Multicenter double-blind Randomized • No benefit with the addition of bupivacaine ROPIVACAINE • S-enantiomer • More selective sensory over motor fibers • Less toxicity and less potent than bupivacaine • No published reports on long term IT administration CLONIDINE • Selective alpha-2 adrenergic agonist • Lipophilic • Induces dose dependent anti-hypersensitivity effect • In animal models reversed hyperalgesia • Reduces mean BP and HR, induces urinary voiding and sedation KETAMINE • N-Methyl-D-aspartate (NMDA) antagonist • Increases spinal action of morphine • S(+)-ketamine traditionally considered less neurotoxic KETAMINE • No published studies on stability in pump • Case report of continuous IT +Ketamine/morphine reduced intractable cancer related neuropathic pain • Long-term antinociceptive effect • Low plasma ketamine levels • No adverse side-effects over 3 months BACLOFEN • GABA-B agonist • Primary indication for spasticity • Antinociceptive effects • May reduce hyperalgesia and allodynia • Stable (90% recovered) at 37o in pump for 14 weeks BACLOFEN • Significant and life threatening overdose and withdrawal symptoms • Overdose • • Respiratory arrest, obtundation, hypotention, fixed pupils Widthdrawal • Hypertention, hyperthermia, hallucinations, DIC, rhabdomyolysis, ARF, and multisystem organ failure • Other side effects • Drowsiness, nausea, HA, muscle weakness and light-headedness GABAPENTIN • Many mechanisms of • • • • • • action Voltage-gated ion channels at postsynaptic dorsal horns that inturrupt neuropathic pain GABA-B agonist ? Supraspinal NMDA antagonist Activates descending noradrenergic system to produce analgesia Supraspinal alpha-2-adrenergic agonist N-type Ca2+ channels • Little clinical data available on IT gabapentin KETOROLAC • COX 1 & 2 inhibitor • Continuous infusion and bolus dosing did not cause spinal pathology or CSF prostaglandin E2 in dogs and rats • IT ketorolac induces potent analgesic activity in rats MIDAZOLAM • Conflicting animal studies on neurotoxicity of IT midazolam • 5-15mg/day did not show signs of neurotoxicity in sheep and pigs • 0.1-0.3mg showed signs of neurotoxicity in rats • Limited clinical data show increased analgesia and synergistic effects with other IT medications NEOSTIGMINE • IT administration may have anti-nociceptive effects by inhibition of c-fos • Prospective trial of 60 pts 50ug of IT neostigmine resulted in post-operative pain relief for ~7hrs with fewer side effects than 300ug IT morphine (Tan et al 2001) • May be limited by GI side effects ADENOSINE • Phase 1 safety studies • Open label dose escalating • 25 subjects • Double-blinded, placebo-controlled • 40 subjects • No effect on BP, HR, EtCO2, or neurologic function • Mixed studies showing lack of post-op pain relief ADRENAL CHROMAFFIN CELLS – INTRATHECAL IMPLANTATION • Cell therapy using intrathecal chromaffin cell allograft is a promising approach for the management of cancer pain refractory to traditional drug therapy and pain lesion surgery. • Preclinical studies on experimental pain models have enabled starting prospective clinical trials. Prior to transplantation, handling and preparation of the chromaffin tissue is critical for allograft viability. • The initial results of clinical trials with human chromaffin cell grafts from intractable cancer pain have reported long-lasting pain relief, in correlation with met-enkephalin release into the CSF. • The limitations of this innovative cell therapy and especially the lack of human adrenal gland availability point to the need for new sources of cells. • Perspectives include xenogenic or engineered cell lines. Lazorthes et al Neurochirurgie. 2000 Nov;46(5):454-65 POLYANALGESIC CONSENSUS GROUP SIDE EFFECTS • Urinary retention • Lower extremity edema • Urinary retention • Pruritus • Myoclonic activity • Sweating COMPLICATIONS • • • • Catheter dislodgement 21% Mechanical failure 20% CSF leak 19% Catheter kinking 12% Cost Effectiveness Urinary retention Pruritis Myoclonic activity Sweating 3 months SPINAL CORD STIMULATION SPINAL CORD STIMULATION • Trial – Patients can trial the therapy • • • Temporary system Only component implanted is lead Patient uses system 3-10 days – Successful trial can be followed by implant • Implantation of neurostimulator, lead(s), and extensions(s) if trial effective 71 SPINAL CORD STIMULATION IN CANCER PAIN • The incidence of neuropathic component in cancer pain is estimated to be around 15% to 40%. • Spinal cord stimulators have been reported as a safe and effective management of neuropathic cancer pain. • Cata et al showed benefit in chemotherapy –induced pain in two patients. • Hamid and Haider showed improved pain relief in radiatherapy-induced transverse myelitis. • Yakovlev et al presented two case reports of cancer patients, with uncontrolled neuropathic pain using conventional medications, who benefitted from the implantation of spinal cord stimulator. • In sum multiple case series, no RCT’s. CATA ET AL Case report of two patients at MD Anderson: Pt A: 61M w/ R elbow melanoma, tx’d w/ IL-2 • Developed BLE neuropathic pain refractory to opioids, gabapentin • Dual lead SCS placement at L1 Pt B: 46M w/ Ewing’s Sarcoma of R infraclavicular region, tx’d w/ Vincristine • Developed BLE neuropathic pain refractory to opioids, gabapentin, amitriptyline • Dual lead SCS placement at T11 Cata et al. Spinal Cord Stimulation Relieves Chemotherapy-Induced Pain: A Clinical Case Report. Journal of Pain and Symptom Management. 2004. 27(1): 72-78. INTERVENTIONS FOR CHEMOTHERAPY INDUCED PERIPHERAL NEUROPATHY: SPINAL CORD STIMULATION Both patients with improved sensory thresholds SUMMARY Interventional Therapies should be Considered for Cancer Pain General Indications • Ineffective analgesia • Intolerable Side effects Less opioid = less side effects = better QOL Earlier interventions have shown better outcomes Possible survival benefit Even more of an impetus in the dying patient The Bottom Line: Patient-Tailored Therapy