Supportive Care for the Cancer Patient

Question 1

What are the pronociceptive mediators?

Answer 1

Cytokines
Interleukins
Chemokines
Prostanoids
Endothelins
Growth factors

Question 2

Where does the generation of pain signals start?

Answer 2

PNS

Question 3

What are the triggers of the pain cascade in cancer?

Answer 3

Tissue compromise
Invasion
Injury

*All from the tumor itself

Question 4

Where are sensory neurons primary afferent fibers and cell bodies located?

Answer 4

Dorsal root ganglia (DRG)

Question 5

What percentage of patients develop late radiation side effects?

Answer 5

5%
2-3 years after finishing

Question 6

In what species is radiation induced pain more common?

Answer 6

Dogs

Question 7

What does CIPN stand for?

Answer 7

Chemotherapy induced peripheral neuropathy

Question 8

What is the pathophysiology of chemotherapy induced pain?

Answer 8

1. Recruitment and activation of immune and glial cells –> production and release of pronociceptive mediators in the DRG and spinal cord
2. Oxidative stress d/t mitochondrial dysfunction
3. Increased activity of voltage-gated and ligand-gated ion channels

Question 9

What is the prevalence of cancer related pain in humans?

Answer 9

33-64%

Question 10

What tumor types are most likely to be associated with pain?

Answer 10

1. Bone tumors
2. CNS tumors
3. GI tumors
4. Inflammatory mammary carcinoma
5. Genitourinary tract tumors
6. Prostate tumors
7. Intranasal tumors
8. Invasive STS
9. Invasive cutaneous tumors
10. Liver and biliary tumors
11. Disseminated intrathoracic and intraabdominal tumors
12. Lung tumors (humans > animals)

Question 11

Which NSAIDs are approved in the EU for long term musculoskeletal pain management in cats?

Answer 11

Meloxicam
Robenacoxib

Question 12

What is a potential benefit beyond analgesic support with the use of piprant NSAIDs?

Answer 12

Grapiprant selective against EP4 prostaglandin PGE2 receptor antagonist – EP4 receptor implicated in cancer metastasis in murine models and EP4 activity promotes breast cancer progression

Question 13

In what situation should acetaminophen be recommended as a frontline analgesic therapy in dogs?

Answer 13

Dogs with renal compromise

Question 14

What is the reason why oral opioid administration in dogs is challenging?

Answer 14

High first pass effect – subtherapeutic plasma concentrations

Question 15

Which oral opioid has shown predictable analgesia when administered subligually in cats?

Answer 15

Buprenorphine

Question 16

Why is tramadol thought to be more efficacious in cats as opposed to dogs?

Answer 16

Cats produce active metabolite M1

Question 17

Why is tramadol administration difficult in cats?

Answer 17

Highly aversive taste even in compounded formulations

Question 18

What are signs of serotonin syndrome?

Answer 18

Altered mental status
- Agitation, restlessness, vocalization, confusion, seizures
Neuromuscular and autonomic dysfunction
- Abdominal pain, vomiting, diarrhea, salivation
- Muscle rigidity, tremors, ataxia, shivering

Question 19

What drugs are contraindicated concurrently with tramadol?

Answer 19

Trazodone
Mirtazapine

Question 20

What are the most common NMDA receptor antagonists in veterinary medicine?

Answer 20

Ketamine
Amantadine

Question 21

When should amantadine be avoided in veterinary patients?

Answer 21

CHF
Hx of seizures
Patients on selegiline, sertraline, or tricyclic antidepressants

Question 22

What anticonvulsant medications are the most effective for neuropathic pain in humans?

Answer 22

Gabapentin
Pregabalin

Question 23

Which tricyclic antidepressant shows the most promise for pain control in cats and based on its use to treat what other chronic condition?

Answer 23

Amitriptyline
Used to treat interstitial cystitis

Question 24

How does low dose lidocaine produce pain relief in cancer patients?

Answer 24

In pain states - aberrantly expressed sodium channels lead to hyperexcitability and ectopic activity in peripheral and central nerves encoding nociceptive information

Lidocaine – inhibits sodium channels

Question 25

In which cancers in the human population are steroids shown to provide analgesia?

Answer 25

1. Bone cancer
2. Spinal cord compression
3. Brain tumors

Question 26

Which cancers in veterinary patients may corticosteroids provide analgesic benefit?

Answer 26

Ulcerated or inflamed mast cell tumors
Cerebral edema secondary to intracranial neoplasia

Question 27

What is the mechanism of bone cancer-related pain?

Answer 27

1. Dysregulated osteoclast activity
2. Activation of nociceptors by prostaglandins, cytokines, and hydrogen ions released in resorptive pits

Question 28

What is the mechanism of action of bisphosphonates?

Answer 28

Synthetic analogs of pyrophosphate and inhibit mevalonate pathway –> inhibition of osteoclast activity

Question 29

What is an uncommon but severe side effect of bisphosphonates?

Answer 29

Mandibular osteonecrosis

Question 30

Why is zoledronate preferred over pamidronate?

Answer 30

1. Rapid infusion rate
2. 100-fold greater anti-resorptive potencyW

Question 31

What is a non-traditional palliative radiation therapy option which has reported improvement in lameness scores of 63% of dogs in a noncontrolled clinical trial?

Answer 31

Samarium Sm153 lexidronam

Question 32

What is the primary palliative radiation therapy protocol utilized in dogs with osteosarcoma which showed clinically appreciable analgesia in 91% of dogs?

Answer 32

8 Gy x 2 on consecutive days (16 Gy total)

Question 33

What is the median duration of pain relief associated with the standard pRT treatment for osteosarcoma?

Answer 33

2 - 3 mos (67 - 95 days)

Question 34

Which chemokine and receptor are commonly involved with neuropathic pain?

Answer 34

CCL2 (chemokine) + CCR2 (receptor)

Question 35

Increased levels of what protein have been described in inflammatory, neuropathic, and cancer models of pain and appears to induce long lasting pain in both animals and humans?

Answer 35

Nerve Growth Factor (NGF)