Neoplasia treatment options and management considerations Flashcards
What do we need to establish about neoplasia before devising a treatment plan?
Histo to assess cells for criteria of malignancy
Grade if malignant
Stage
Describe cancer grade
Grade describes the appearance of the cancer cells and surrounding tissue
Low grade tumours contain organised cells and look more like relatively normal tissue
High grade tumour tissue is disorganised and cells look very abnormal
Describe cancer stage
Describes the size of the tumour and how far it has spread from where it originated
What do we need to do to determine cancer stage?
Palpate/sample local lymph nodes
Image other sites in the body to determine presence of any metastases (usually thorax/abdomen)
What information do we need to make a targeted cancer treatment plan?
The full extent of the cancer and if/where it has spread
How the tumour is likely to behave clinically
How the cancer is likely to progress
What are the treatment options for cancer?
Monitor
Treatment:
- surgery
- chemotherapy
- radiotherapy
- multimodal
- other (cryotherapy, photodynamic therapy, emerging immunotherapies)
Euthanasia
What are the different forms/aims of cancer treatments
Definitive cure
Remission- a decrease or disappearance of signs of cancer, but cancer cells may still be present in body
Palliation- relieves clinical signs but does not treat the cancer itself
What are the different aims of surgery in cancer treatment?
Curative
Cytoreduction/debulking
Management of oncological emergencies
Palliative
What are the uses of chemotherapy?
A primary treatment where surgery is not possible e.g. lymphoma, leukaemia
An adjunct treatment following surgery to ‘mop up’ any cancer cells left behind or micrometastases
Typically used to slow cancer progression (increase median survival time), rarely curative
How does chemotherapy work?
Drugs enter body and target rapidly dividing cells (including non-cancer cells)
=> side effects
In particular:
- bone marrow => neutropenia
- fur/whiskers => alopecia
- GIT => gastroenteritis
How can the side effects of chemotherapy be managed - bone marrow/neutropenia
Monitor with complete blood count
Antibiotics indicated if severe or symptomatic
How can side effects of chemotherapy be managed? - alopecia
Supplementary essential fatty acids may help
Moisturising shampoos may prevent associated itching
How can the side effects of chemotherapy be managed? - GIT/gastroenteritis
Anti-emetics
Hospitalisation for IVFT if severe
Diarrhoea only needs treating if severe- antibiotics +/- anti-diarrhoeals
Why is patient temperament important to consider when choosing chemotherapy as a treatment option?
Patient will require multiple clinic visits
Many drugs need intravenous administration
Most protocols also require oral administration at home
What is radiotherapy?
Use of ionising radiation to treat solid tumours
What are the different methods of delivery of radiotherapy?
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)
How does radiotherapy work?
Radiation causes DNA damage in all exposed cells => cell death
Focussed radiation delivered in small doses on a regular basis minimises risk of carcinogenesis
Local therapy with no systemic side effects
What are the possible aims of radiotherapy?
Curative treatment
Palliative treatment
Describe radiotherapy as a curative treatment?
Usually as an adjunct following surgical removal of tumour to kill any microscopic cancer cells left behind e.g. mast cell tumours, soft tissue sarcomas
Also used as a sole treatment in some radiosensitive tumours that are inoperable or surgery not recommended or desired
e.g. CNS tumours, anal sac tumours
Usually delivered in fractions 3 times a week over 4 weeks
Describe radiotherapy as a palliative treatment
Slowing growth and relieving clinical signs of inoperable tumours e.g. nasal or CNS tumours
Pain relief e.g. osteosarcomas
Usually delivered once a week over 4 weeks (hypofractionated)
What are the considerations when including radiotherapy in a cancer treatment plan?
Must consider patient temperament, co-morbidities, and travelling practicalities
Only 6 centres in the UK that deliver radiotherapy
Curative-intent radiotherapy requires 12 visits in 4 weeks
Each radiotherapy session is delivered under a short general anaesthetic
Describe palliative care as an option for cancer treatment
Aim is to provide relief from pain and clinical signs of cancer, NOT treat the cancer itself
e.g. analgesics, anti-emetics, appetite stimulants
Focus is on quality of life
What are the red flags that suggest euthanasia should be considered?
Euthanasia should be considered when treatments do not help or are no longer effective and the 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)
