Feline Bone Tumour

Re: Feline Bone Tumour

Richard Fox — Mon, 09 Jan 2012 09:18:47 GMT

I would suggest:

1. If money and owner compliance allows - deep core bx

2. if no complience / money and there is def. lysis without sings of infection then go for amputaion myself then chop out lesion and send for histo for long term prognosis is required?

3. If there is bone lysis then tumour is most likely. Apendicular osteosarcs tend to have a lower metastatic potential than canine ones IIRC but prognosis still very guarded they to have a much greater median survival time. This tends to make them better candidates for amputation.

Re: Feline Bone Tumour

Braden Collins — Mon, 09 Jan 2012 09:11:27 GMT

I would certainly agree that chemo is not something to be recommended. It may be something to mention to the owners though so they can make an informed decission. I can't say I've seen enough cases to make much of a judgement myself on other areas, so I'm afraid I'm just on the books there.

Re: Feline Bone Tumour

Judith Joyce — Mon, 09 Jan 2012 08:52:58 GMT

[quote user="Braden Collins"]Median survivals are from Wintrow and McEwen's Small Animal Clinical Oncology. Article Referenced is Bitetto WV, Patnaik AK, Schrader SC et al: Feline Osteosarcoma 22 cases (1974-1984).[/quote]

I haven't seen the book but my query came from my familiarity with the numbers in that paper: 15/22 cats had appendicular osteosarc and all were middle-aged or older cats. 3/15 killed at dx; 12/15 amputated and of these, 6/12 were still alive 5 years later. The others had had a median survival time of more than 4 years. In essence, it appears that following diagnosis of appendicular osteosarc and amputation, the cats lived long enough to die of something else.

From this, I can't see any place for chemo, especially speculative regimens extrapolated from another species for which the evidence base is poor.

All but one of the appendicular osteosarcs in this series were metaphyseal and that reflects my experience.

Malcolm N

Re: Feline Bone Tumour

Braden Collins — Mon, 09 Jan 2012 04:02:22 GMT

Median survivals are from Wintrow and McEwen's Small Animal Clinical Oncology. Article Referenced is Bitetto WV, Patnaik AK, Schrader SC et al: Feline Osteosarcoma 22 cases (1974-1984).

The protocol is from notes in the University of Sydney Medical Oncology Distance Education Course. I believe it is largely extrapolated from similar protocols in dogs.

As for what type of tumour/disease process it is, only histopath will tell. Site predispositions don't rule in or out a diagnosis, so whatever treatment is chosen it should be diagnosed properly from the start.

Re: Feline Bone Tumour

Judith Joyce — Fri, 06 Jan 2012 18:40:22 GMT

Where do these numbers come from and what evidence do you have for the use of chemo in general and this protocol in particular?

Osteosarcomata are usually metaphyseal and I think that a previous post said this tumour was diaphyseal. Many, perhaps most tumours of the diaphysis that I see are mets and not primaries.

Malcolm N

Re: Feline Bone Tumour

Braden Collins — Fri, 06 Jan 2012 02:07:14 GMT

I would agree that radiographs do not provide an exact diagnosis, but you can be fairly suspicious. Assuming it is an osteosarcoma, there is about a 20% metastatic rate. Amputation alone has been shown to have a 2-4 year median survival, so this is not a bad option as a sole treatment. Some people argue that with a 20% metastatic rate, it may be worth considering adjunctive chemotherapy. My choice would be carboplatin and doxorubicin (or you could do either of these on their own) if the owners were keen to do this, but I'm not sure it is something I would personally recommend.

Re: Feline Bone Tumour

Evelyn Barbour-Hill — Thu, 05 Jan 2012 20:13:53 GMT

[quote user="robloxley"]

[quote user="Wren"]Radiography confirmed a bone tumour[/quote]

Can radiography do this?

[/quote]

Near as dammit, it can.

Re: Feline Bone Tumour

Wren — Thu, 05 Jan 2012 18:56:04 GMT

[quote user="robloxley"]

[quote user="Wren"]Radiography confirmed a bone tumour[/quote]

Can radiography do this? I thought you needed cytol/histol to be sure... FNAs (sent to a good cytologist) can often be helpful. Equally I accept that if everything points towards a tumor then amputation may be the sendible next step, I just remember a report of a cat whose bony lesion turned out to be TB![/quote]

Sorry, not usually so sloppy in my choice of words but I'm tired and grumpy! Please accept my apologies.

The owner has decided on amputation which one of the SA bods will do tomorrow (although they aren't here today so they don't know it yet!). Hopefully it will all go well. I remember radiographing lung mets years ago on a flatcoat who'd had a leg amputated due to osteosarcoma. They were horrible and the dog was put to sleep not all that long after the amputation. Have been checking the literature and it would seem that cats have a much better outcome so we shall cross our fingers.

Re: Feline Bone Tumour

Mark Holmes — Thu, 05 Jan 2012 16:17:38 GMT

I would amputate forequarter ie including scapula.

Re: Feline Bone Tumour

Rob Loxley — Thu, 05 Jan 2012 16:09:12 GMT

[quote user="Wren"]Radiography confirmed a bone tumour[/quote]

[quote user="Wren"]Is this a good plan for a cat forelimb where the whole of the humerus needs to be removed?[/quote]

I'd be thinking of a forequarter amputation. Cats do very well on 3 legs, and in my experience feline bone tumors do really well for a good long time (unlike the dogs where the prognosis is usually pretty grim).

Re: Feline Bone Tumour

Kate Richardson — Thu, 05 Jan 2012 14:56:30 GMT

Definitely worth amputating if it is an osteosarcoma, much much less likely to metastasise compared to dogs.

Re: Feline Bone Tumour

Neil Wheadon — Thu, 05 Jan 2012 13:52:52 GMT

I'd amputate if a tumour

According to Ettinger - Osteosarcomas are the commonest bone tumour and the mean survival time is 5.5-6.1 months, with most euthanased due to local recurrance rather than metastatic disease. So removal at the shoulder would be a good idea and I have done this in dogs.

If the owner is happy and the cat is happy then as long as the costs/risks are explained, then do this. Pallative care, tumours are painful and would be a short term option. 3 legged cats do really well and with cats living longer and longer you may be gifting more years, and the operation would be interesting to do..

Good luck

Neil