Canine lymphoma how long do you treat?

Re: Canine lymphoma how long do you treat?

Richard Fox — Mon, 08 Nov 2010 13:44:42 GMT

Sorry I should have said most or generally - I am not normally emphatic about these things sorry yes we did have a high grade T-cell rich B-cell a few months ago :( But I guess academically these are not indolent :)

I should have been more clear AND said indolent lymphomas are not multi-centric neoplasms they most often occur as one or a small collection of enlarged lymph nodes and are slowly progressive. Think before you type ;)

Re: Canine lymphoma how long do you treat?

Christopher Saul — Mon, 08 Nov 2010 13:32:35 GMT

[quote user="Richard Fox"] T-cell rich B-cell lymphomas and indolent lymphomas are cytologically distinct from the above and of generally much lower grade. [/quote]

[quote user="Richard Fox"]These however are not multi-centric neoplasms they most often occur as one or a small collection of enlarged lymph nodes and are slowly progressive. [/quote]

Not in this case Richard! this was mutlicentric allright, we had involvement in the popliteal, inguanal, prescapular and submandibular lymph nodes. cytology from the initial aspirates was described as ( no quotaiton marks here, it was a long time ago and I'm going from memory) early lymphoproliferative disease, probhable.

Sometimes I wish I had written this case up in JSAP, it was an unusual one, there was much discussion with the pathologits at NW labs and also glasgow uni before a diagnosis was reached.

Re: Canine lymphoma how long do you treat?

Richard Fox — Mon, 08 Nov 2010 13:06:01 GMT

Most dogs with acutely arising multi-centric lymphoma are high grade B-cell lymphomas. T-cell rich B-cell lymphomas and indolent lymphomas are cytologically distinct from the above and of generally much lower grade. We have had quite a few cases of indolent lymphomas in dogs over the past 5 years including several T-zone lymphomas but little is known about their response the chemo as they occur so infrequently. The subsets as Chris describes are generally quite uncommon but certainly early stages can easily be overlooked. These however are not multi-centric neoplasms they most often occur as one or a small collection of enlarged lymph nodes and are slowly progressive.

If you want to know more then the AFIP WHO tumour fascicle on haematopoietic tumours is the place to go but is a daunting read even for me :)

http://www.afip.org/consultation/vetpath/who/whohema.html

Re: Canine lymphoma how long do you treat?

Martin Atkinson — Mon, 08 Nov 2010 12:50:37 GMT

There was a paper in this week's (Nov 6th) Vet Record on a 13 week dose intensifying chemotherapy course with what appears to be a modified madison protocol with apparently good results. The addition of Asparaginase into chemo protocols has been questioned by some authorities but anecdotally it seems to help.

Re: Canine lymphoma how long do you treat?

Christopher Saul — Mon, 08 Nov 2010 12:34:10 GMT

Firstly, good skills on 13 months remission so far!!

It would be interesting to know if you did immunohistology on this one?... Few years back I had a case of a T-cell rich, B-cell lymphoma. I had submitted lymph nodes for histo as well as numerous cytologies. Was stage IV at diagnosis. I used a continuous COP protocol (had a heart murmur and owners were reluctant for CHOP) and the dog went into remission for more than 2 years, whereupon it went into renal failure, presumably in part as a result of my chemo.

There have traditionally been 2 schools of thought; 1] maintenance therapy long term or alternatively 2] discontinuous therapy (usually 6 months but sometimes 12 ) whereupon therapy is withdrawn and an induction protocol re-introduced upon relapse.

Current recommendations for CHOP protocols are to use discontinuous rather than maintenance therapy ( Withrow and MacEwen's Small animal clinical oncology, 4th edition eds Withrow and Vail, page 713). I cannot find any info on whether to do this with COP, presumably because COP patients generally don't live long enough or maybe it's just not popular with referral oncologists.

My own thoughts on this matter are (Don't quite me this is just anecdote) is that overall survival times are similar for both approaches, but animals with discontinuous therapy spend less time on chemo than those on maintenance and so run less risk of side effects ( see my own experience aboove!).

Having said that if you are now at a point 13 months in, and you withdraw therapy now you'll feel bad if it relapses ( I've been there!). I guess all you can do is be open with the owners and help make a joint decision with them about what to do next. ( things to consider include how well the dog tollerates therapy, financial constraints etc). Food for thought, with my case I found that round about the 18 month mark the veins started to get really difficult to find!!

I feel that there are distinct subsets of lymphoma patients with disctinct diseases which we have yet to classify.

Hope this helps

Chris

Re: Canine lymphoma how long do you treat?

Richard Fox — Mon, 08 Nov 2010 11:25:58 GMT

[quote user="Martin Atkinson"]I wonder if the lymphoma biomarkers may be a useful tool for monitoring relapse (or not) as they are not particularly useful as an initial diagnosis.[/quote]

I think this type of test is very misleading (personal opinion) as there is no good science to suggest it is sensitive or specific for lymphoma and I do not recommend to any of my clients.

Re: Canine lymphoma how long do you treat?

Martin Atkinson — Mon, 08 Nov 2010 11:03:16 GMT

One of the problems here I guess is that because not many survive this long and we tend not to classify our lymphomas accurately there is precious little data. I have a CKCS which had modified Madison protocol for lymphosarcoma and is still alive 2.5 yrs later with no evidence of recurrence. I have elected to keep it on prednisolone at anti-inflammatory rate every other day having gradually reduced the dose from chemotherapeutic doses slowly over several months from the end of the primary course. This was an unusual case because the peripheral lymph nodes have never been enlarged and as far as I could detect was confined to the sub-lumbar region and the kidneys. The initial symptoms were therefore haematuria and a sub-lumbar mass. I check it every 3 months now and test the urine for blood and palpate the abdomen - so far so good. I wonder if the lymphoma biomarkers may be a useful tool for monitoring relapse (or not) as they are not particularly useful as an initial diagnosis.

Re: Canine lymphoma how long do you treat?

Hannah Wynne Richards — Mon, 08 Nov 2010 11:02:09 GMT

If you've built up a good relationship with a referral centre, which has an oncologist, then try asking them

Wynne

Re: Canine lymphoma how long do you treat?

Richard Fox — Mon, 08 Nov 2010 10:50:10 GMT

Does to me esp if the architecture has been effaced! and the lesions were multicentric. BTW I was not questioning the pathologst . I always like to review a case that is behaving out of the norm. Like the malignant round cell tumour (very nasty on histo) I diagnosed in a 9 week old puppy that has now all regressed and has not stained for anything on immuno so far and has now gone to America for clonality testing and further specialist immuno

Utlendigur - that's what I understood but my opinion was a personal one rather than based on science . Maybe give the owner all the information you have and let her/him decide?

Re: Canine lymphoma how long do you treat?

Andrew Mellor — Mon, 08 Nov 2010 10:46:16 GMT

histo performed by Jane Miller at Nationwide , very experienced and always seems on the ball.

Re: Canine lymphoma how long do you treat?

Utlendigur — Mon, 08 Nov 2010 10:45:15 GMT

The last time I had a case that went into (and stayed in) remission, I seem to remember the advice was that if they were in remission at 6months there was no significant benefit in continuing the chemo longer than that. At some point they will recur but beyond 6mnths the chemo didn't seem to affect recurrence. Things may have changed since then though.

Re: Canine lymphoma how long do you treat?

Andrew Mellor — Mon, 08 Nov 2010 10:44:26 GMT

would you say that the histo discription sounds fairly much clear cut ?

Re: Canine lymphoma how long do you treat?

Richard Fox — Mon, 08 Nov 2010 10:40:39 GMT

Fair enough :) Just first easy thing to check and have been asked to do so a few times :) Not sure then if there is a firm answer - I personally would keep treating but that's not based on pure science :)

Re: Canine lymphoma how long do you treat?

Andrew Mellor — Mon, 08 Nov 2010 10:32:48 GMT

[quote user="Richard Fox"]

Maybe worth reviewing the original histo results - I presume it was not a diagnosis made on cyto alone?

[/quote]

fnab was clear so biopsied whole node and histo for lymphoma -" lymph node architecture is extensively replaced by medium-sized lymphoid cells with prominent nucleoli and moderate mitotic rate"

Re: Canine lymphoma how long do you treat?

Richard Fox — Mon, 08 Nov 2010 10:00:46 GMT

Maybe worth reviewing the original histo results - I presume it was not a diagnosis made on cyto alone?