unpublished UK paper on 68 hypophysectomy cases

I have been in touch with WSU in Pullman WA about a possible hypophysectomy for Kierra. Dr. Owen wrote the following in an email:

"Currently there are no long-term publications on long-term outcome after hypophysectomy in cats with acromegaly. There was a study, not published yet out of the UK on 68 cases. They reported an 88% survival rate with a 12% mortality rate. Of the surviving cats, 70% had complete remission of their diabetes, in other words no longer required insulin. 25% had a reduced insulin requirement and 5 % were unchanged with their diabetes. The bigger the tumor the poorer the outcome. If the tumor is small and can be removed in it’s entirety the prognosis is good. The long-term survival with this group of cats was 2.3 years with a recurrence rate of 13%."

I am surprised the long-term survival is only 2.3 years. Hard to know what that really means though since the full paper is not available to know more about the cases, like age, tumor size, etc.

 

Ask Dr. Owen what their particular survival rate is at WSU. And how many acro cats they've done now. I've only heard of two cats that went there. One had a bleeding problem. The second, the tumour was not removed completely and the caregiver ended up having to have SRT (elsewhere) afterwards. Thought I heard they'd stopped doing the surgery. At the time we went for SRT at CSU, the average life span was 2 years after SRT. Neko lived 4.5 years. Remember, these cats generally are older cats to start with. Of the cats here that went to SRT around the time we did, half passed from cancers so totally unrelated conditions.

 

This doesn't sound too promising to me. I think the SRT average life span is comparable to this. Less risk. Less Invasive.

Thank you for sharing this information.

 

Dr. Owen said a pre-print is not available (maybe I willl try to send a request to the author) but she sent me a proceedings from a meeting which reported on 60 cases. In the paper, it says 95% confidence level for 1.3-3.3 years. I asked her about her own surgeries and she said this: "

"Yes, I have been involved in all 75 surgeries, between LA and here. As far as what we have observed after surgery is difficult to condense into an email. We know cats and dogs with smaller tumors have a longer survival time, a better outcome with surgery and a lower recurrence rate. Mortality associated with this surgery is between 8-10% with small tumors and can be as high at 30% with larger tumors. Mortality rate in this case is defined as any patient that dies within 4 weeks of surgery. The majority of the patients wake up from anesthesia and are a normal patient. There are significant electrolyte changes that we manage quite intensively after surgery. These changes are controlled by the medications I mentioned below and are adjusted based on blood work and clinical signs. Some patients do not wake up from surgery and remain in a comatose state, these patients are typically those that do not survive. The majority of patients recover from anesthesia and are eating and drinking the day following surgery."

Wendy - are there any papers about long-term survival after SRT? I am realizing the surgery is not the panacea I thought it was. How about long-term survival simply giving the high insulin doses? And then there is the cabergoline route. I am contemplating if anything really extends their lives beyond giving the high insulin doses? Do you think (or know?) Neko would have lived as long without the SRT? And did you ever think about trying cabergoline? Did you have to do imaging when you did the SRT? Is the SRT specialized and only done at certain locations? Sorry for so many questions, direct me to where this info is if it is already here somewhere on the FDMB.

 

Interesting they mention 75 surgeries, but also lump dogs into the list. It is a surgery for treating Cushings too. A more specific question - how many cats with hypersomatotropism have they performed surgery on - might be more informative. I searched through the Acrotracker file, and didn't see a single mention of anyone going to WSU for surgery. There are a couple posts here on cats that went to AMC in New York. One, Schmee, relapsed in diabetes.

Not that I know of. The figure I gave was a quote from the internal medicine vets at CSU, the place with the most experience at the time we went there. They did find the same thing as that RVC paper, a large number of cats died from other conditions. That means it's harder to get a good number on how many cats specifically died from acromegaly. And even then it's still hard to differentiate. Neko had heart disease, kidney disease and small cell lymphoma. At least the first two are common in acros, though with Maine Coon heritage heart conditions are also an issue. I've seen a number of GI issues in acros, but did it helped in spite of the acro?

It widely ranges. Here is one post I did on the upside. On the down side, I've seen several cats last not much longer than a year. Heart conditions are quite common. Unfortunately they are often "silent killers" because you don't know about them until quite late. They are treatable though if found in time, so I would suggest getting her heart looked at. I had a civvie who had a thromboembolism two days before his scheduled echocardiogram. And again, you have old cat diseases to contend with, cancers being a common one.

I have no idea how Neko would have done without SRT. No one can guess that. Her QOL was way better after though. And so was mine. The only options available at the time of Neko's diagnosis was SRT or just insulin. Cabergoline came much later. Imaging was done with SRT - they need to map the tumour to plan the radiation therapy so as to not damage any of the surrounding brain tissue.

The equipment for performing SRT is expensive, and so even is the cost of the cement needed to line the room where it takes place. This post has some places listed, but doesn't have anything added for the last couple years, I'm sure the list is longer now:
Places to get Acro treated and notes I took in Sept 2015 At one point WSU did SRT too and we had one member go there, post here, though more elsewhere you can search on that member.

 

I stand corrected. Did some researching in the vault of papers. Stereotactic Radiation Therapy for the Treatment of Functional Pituitary Adenomas Association with Feline Acromegaly, by Wormhoudt, Boss and LaRue. Susan LaRue was the head of Radiation Oncology when we were at CSU. From the paper " The median overall survival time for all patients after SRT, was 1072 days", or almost 3 years. See section 3.4 of the article for more detail. Some of the cats were still alive when they did the calculation, so the survival time would be longer. And there is the usual list of other unrelated diseases (mostly cancers) that took some of them.

 

Good point, I will ask.

What is the best way to do this?

https://felinediabetes.com/FDMB/thr...treated-and-notes-i-took-in-sept-2015.146553/
"And for a list of sites (around the world) and their radiation capabilities: members of the vet cancer society."
This link is no longer working.

 

Great find, thanks!

 

Start with the vet listening to her heart. If they hear anything off, an echocardiogram.

Poke around that site, I found the link inside of 10 seconds. http://vetcancersociety.org/wp-content/uploads/2019/07/radiation-facilities.pdf

 

Thank you. I was afraid it was going to be a rabbit hole since I wasn't sure what to search for... Looks like there is no SRT in WA state unfortunately.

 

I was poking around that vet cancer society site some more, found that UC Davis has a study on pituitary surgery that pays for a large part of the costs. More details here, if you want to inquire.

I seem to remember from someone else that they stopped doing SRT at WSU. We did have one member who drove there from Oklahoma to get it done.

 

That is interesting. After seeing the UK info, I don't think we will do the surgery. No matter what, this is a tough journey.

 

Dr. Owen said this -- "We have performed surgery on 13 cats, two with Cushing’s disease the others with hypersomatotropism."