Neoplasia treatment options

Question 1

What do we need to establish about neoplasia before devising a treatment plan?

Answer 1

Histopathology to assess cells for criteria of malignancy

Once we have determined it is malignant, we can grade it

Then assess neighbouring lymph nodes & distant tissues/organs to stage it

Question 2

What are cancer grades

Answer 2

Grade describes appearance of cancer cells & surrounding tissue

Low grade tumours contain organised cells & look like relatively normal tissue

High grade tumour tissue is disorganised & cells look very abnormal

Question 3

What are cancer stages

Answer 3

Describes:
- size of tumour
- How far it has spread from where it originated

Question 4

How do we determine cancer stage?

Answer 4

To determine stage we need to:
- Palpate/sample local lymph nodes
- Image other sites in body to determinepresence of any metastases (usually thorax/abdomen)

Question 5

What information do we need to make a targeted cancer treatment plan?

Answer 5

Full extent of cancer & if/where it has spread

How tumour is likely to behave clinically

How cancer is likely to progress

Question 6

How do we make a treatment plan?

Answer 6

Talk to oncologist to get all options
- they can also help with giving more precise prognosis

Then talk owners through pros & cons of all available treatment options

Be mindful of:
- The fear of cancer
- Owners’ personal experience of cancer & its treatments

Question 7

What are the possible treatment approaches?

Answer 7

1. Monitor
2. Treatment
   a) Definitive cure
   b) Remission- decrease or disappearance of signs of cancer, but cancer cells may still be present in body
   c) Palliation- relieves clinical signs but doesn’t treat cancer itself
3. Euthanasia

Question 8

What are some important considerations when choosing a treatment plan?

Answer 8

Cure vs palliation

Expected & potential side effects

Quality of life

Realistic expectation as to survival time

Question 9

Describe monitoring as a cancer treatment approach

Answer 9

Watchful waiting

Can be appropriate where co-morbidities preclude further investigations or putative treatments

Must be satisfied that animal isn’t suffering & that owner can recognise if this changes
- Consider using pain scores or quality of life surveys

Not enough for owner to say they don’t want/can’t afford treatment

Question 10

What are the possible treatment options for cancer?

Answer 10

Surgery

Chemotherapy

Radiotherapy

Others (cryotherapy, photodynamic therapy, emerging immunotherapies)

Multimodal approach used when appropriate

Question 11

What are the possible aims of surgery?

Answer 11

Curative (surgery cures more cancer than any other treatment)

Cytoreduction/debulking

Management of oncological emergencies

Palliative

Question 12

What are the uses of chemotherapy?

Answer 12

Primary treatment where surgery isn’t possible
- e.g. lymphoma, leukaemia

Adjunct treatment following surgery to ‘mop up’ any cancer cells left behind or micrometastases

Typically used to slow cancer progression, rarely curative (increase median survival time)

Question 13

How does chemotherapy work?

Answer 13

Work by targeting rapidly dividing cells

Includes tumour cells but also normal cells in body => side effects

In particular:
- bone marrow
- fur/whiskers
- GIT

Generally better tolerated by animals than people

Question 14

How can neutropenia (due to affect on bone marrow) as a side effect of chemotherapy be managed?

Answer 14

Monitor with complete blood count
Antibiotics indicated if severe or symptomatic

Question 15

How can hair loss (fur & whiskers) as a side effect of chemotherapy be managed?

Answer 15

Supplementary essential fatty acids may help
Moisturising shampoos may prevent associated itching

Question 16

How can gastroenteritis (due to affect on GIT) as a side effect of chemotherapy be managed?

Answer 16

Anti-emetics
Hospitalisation for IVFT if severe
Diarrhoea only needs treating if severe
- antibiotics +/- anti-diarrhoeals

Question 17

What are some important chemotherapy considerations?

Answer 17

Must consider patient temperament

Patient will require multiple clinic visits
Many drugs need intravenous administration
Most protocols also require oral administration at home

Question 18

What is radiotherapy?

Answer 18

Use of ionising radiation to treat solid tumours

Question 19

What are the different methods of delivery of radiotherapy (classifications)?

Answer 19

External beam radiation (Teletherapy)(most common)
- Delivered (x-rays or gamma-rays)

Interstitial beam radiation (Brachytherapy)
- Implanted (gamma or beta-rays)

Systemic radiation therapy
- Injected (e.g. radioiodine)

Question 20

How does radiotherapy work?

Answer 20

Radiation causes DNA damage in all exposed cells –> cell death

Focussed radiation delivered in small doses on regular basis minimises risk of carcinogenesis

Local therapy with no systemic effects

Question 21

What are the possible aims of radiotherapy?

Answer 21

Curative treatment
- Adjunct following surgical removal of tumour to kill any microscopic cancer cells left behind (e.g. mast cell tumours)
- Sole treatment in some radiosensitive tumours that are inoperable or surgery not recommended (e.g. CNS tumours, anal sac tumours)
- Usually delivered in fractions 3x/week over 4 weeks

Palliative treatment (short-term/poor prognosis)
- Slowing growth & relieving clinical signs of inoperable tumours(e.g. nasal or CNS tumours)
- Pain relief(e.g. osteosarcomas)
Usually delivered 1x/week over 4 weeks (hypofractionated)

Question 22

What are some important radiotherapy considerations?

Answer 22

Must consider patient temperament, co-morbidities & travelling practicalities

Only 6 centres in UK that deliver radiotherapy

Curative-intent radiotherapy requires 12 visits in 4 weeks

Each radiotherapy session is delivered under short general anaesthetic

Question 23

Describe palliative care as a cancer treatment approach

Answer 23

Aim is to provide relief from pain & clinical signs of cancer, NOT treat cancer itself

e.g. analgesics, anti-emetics, appetite stimulants

Focus is on quality of life

Question 24

Describe euthanasia as a cancer treatment approach

Answer 24

Considered a positive option once QoL can no longer be maintained

Support owners in their decision-making & provide tools to help them recognisewhen their pet has had ‘enough’
- Ask owner to think about 3 key things their pet enjoys doing- when they can no longer do them then it is reasonable to consider euthanasia
- Use quality of life surveys/scales

Question 25

What clinical signs mean euthanasia should be considered?

Answer 25

Euthanasia should be considered when treatments don’t help or are no longer effective & animal is having difficulty with:
- Breathing
- Eating/drinking
- Elimination (either through incontinence or inability to move)
- Standing and walking
- Pain (owners may need help recognising this)