results for MCT & FNAs
February 8th, 2012 § Leave a Comment
Just when I was worrying about not having enough results, we are suddenly drowning in results… but what to make of them? Things are perhaps only slightly clearer.
Here we go:
The vet got good margins on the MCT, meaning that the cells around the edge of what was removed were healthy cells and hopefully we have all of it.
It was a Stage 2 MCT. This makes it a difficult one to call. Stage 1 MCT means that (in theory) the lump is whipped out and that’s it, it is unlikely to spread. Stage 3 means your dog is at death’s door, and it’s likely to have spread. Stage 2 is the category everything else gets chucked in, so it is a bit of a catch-all category with a variable outlook. The report from the lab stated that 5-22% of Stage 2 MCTs metastasise (spread elsewhere). Which is a huge variation.
This helpful article says: ”It is reported that 50-75% of dogs with Grade 2 MCT survive long-term (beyond 35 weeks). Another study concluded that 44% of dogs with Grade 2 MCT survived long-term (over 4 years) after nothing more than complete surgical removal of their tumors. Yet another author reports a 45% mortality rate.” So that’s nice and clear, then. Go figure. Apparently, there are other indicators to help you further… such as…
The ‘mitotic index’, which is a measure of how fast the cells were dividing. The higher, the faster and the more aggressive the cancer; the more chances of it recurring or spreading. For Slate, this result was <1 (less than 1). Apparently this is great, since anything up to 5 is really good, and less than one is great.
As this paper states in an abstract, “For grade II tumors with a [mitotic index] < or =5, the median survival time (MST) was 70 months”. So, the average survival time of dogs with a stage 2 MCT and a mitotic index of 5 or less is 70 months. 70 months doesn’t sound long, but is actually 5.8 years. If Slate, at 7.5yo, lived another 5.8 yrs – to be 12 or 13 – we would be lucky, even without all this! So this is an excellent result, really.
Another nice and more easily-readable article about the ‘mitotic index’ and why it is important for prognosis can be found here, on the Dog Cancer Blog. I can now perhaps stop beating myself up for not acting sooner.
We are still waiting on a Ki-67 result, which will apparently give us more info on how likely it is to have spread. But this doesn’t seem to be as important/significant as the mitotic index.
The fine-needle aspiration results on the remaining 5 lumps: Two of these came back as follicular cysts (benign). The remaining 3 lumps were ‘inconclusive’, meaning that there was not enough material for the lab to be able to analyse what it was. The lab did say they found no mast cells in these samples. But neither did they find much else, it seems. However, this is one thing we are going to pursue further on Monday, possibly repeating the 3 FNAs to see if we can get any better results. (More Slate-needle torture.)
So that’s it, for today.
The vet did talk about us seeing an oncologist, and mentioned the centre in Cambridge as being the best in the country, and there also being the North Downs Specialist Referrals Centre to consider if we wanted somewhere a bit closer to home. This would be for a CT scan and further diagnostic testing to see if it has spread. He also mentioned doing a lymph node biopsy, since the lymph nodes in the groin are where any MCT cells would have drained to, from the MCT – this wouldn’t need a referral.
However, all these would require more G.As and we’re reluctant to go all out on invasive testing and further G.As “just to be sure”. On the other hand, our insurance will only cover us for MCTs for 12 months and up to £4K. So, from a financial perspective it makes sense to use that up now, with further tests – because if we miss something now and it crops up in a year, we won’t be covered.
Finally, none of this quite answers why her liver enzyme results were raised in the bloods taken beforehand, or the slightly-yellow poos. The vet said this indicates inflammation of the liver, to some degree, yet any number of things could cause raised liver enzymes and mild pancreatitis: If you had a few too many to drink, your liver enzymes would be raised the next day. Or exposure to any toxins (environmental) could also cause them to be raised. Metronidazole has been known to be a cause of pancreatitis, and the very yellow poos came immediately we stopped the metronidazole before Xmas.
He suggested we might re-test some more bloods in a month or so, so we can see if they are still raised or if this was a one-off thing.
Anyway, it is now a case of – how far do we go with all this testing and how invasive should we be?
But the results are pretty good so far and we are cautiously optimistic.
