Of course! Apologies to Dr Pam.

To follow up on the original topic of Crush's tumour, I connected with Dr Edwards the rehab vet today. It must have been a clerical mixup, we don't need a new referral and she was able to give me some good advice over the phone for his injury, and we planned a appointment from August 18th, provided he's well enough to travel by then. One of the things she mentioned was relevant to his met. We are going to try putting him on Low Dose Naltrexone (LDN) going forward to manage some of his chronic pain, which she said is also being studied for it's uses in slowing down tumour growth in humans and animals. We'll be it mainly for pain control, but it can't hurt with the cancer. It also is sometimes used to offset symptoms of chemotherapy so it could be useful if we go that route after consulting with the oncologist.
I looked up LDN and did see a fair bit of research come up on it's uses for breast cancer, cervical cancer, colo-rectal cancer. Curious if Dr Pam or anyone else here has heard of it being used for osteosarcoma mets? I'm interested to give it a shot, although I know it's a longshot. 

Here is the product description I got from Dr Edwards, I've pasted the text here as I don't think I can upload files.
I put some links to studies at the bottom as well, I have access to the full text from all but the first but again, can't upload files... If anyone is interested in reading more than the abstract I could email you.
Googling "low dose naltrexone" and "cancer" brings up a ton of results, and some websites that seem dedicated to promoting it's promise. However from what I can tell, actual research is still in it's early stages (mice) and the pathways through which it acts aren't yet understood.The human and canine benefits are mostly anecdotal from what I can see. The bottom three articles here share some common authors as well, so make of that what you will... They appear to be published in reputable journals though. In regards to cervical and breast cancer I did see several other articles written by others as well.

Chronic Pain can be very difficult to
recognize in some of our pets as they
cannot communicate how they are
feeling and some instinctively attempt
to hide their discomfort. It is important
for clients to realize that just because
their pet does not cry, limp, or stop
eating; it does not mean they are not
experiencing pain.
It is often easier to recognize acute
pain in our pets because it serves the
body a useful purpose. This pain is
usually due to trauma or inflammation
and helps to protect the body by
encouraging rest, healing, and
recovery.
Chronic pain or “maladaptive pain” is
often more difficult to recognize. This
is a result of the body being exposed
to long term pain signals which
ultimately allows the body to become
more efficient at experiencing pain.
Common conditions that may
contribute to chronic pain include
obesity, organ disease, joint disease,
and spinal cord or nerve damage.
Successful management of chronic
pain often includes a multi-modal
approach that may include
rehabilitation medicine as well as
medications.
Physical medicine supports the body
to heal and helps to restore functional
ability.

Therapeutic exercises and modalities
such as low-level laser therapy
(photobiomodulation) and medical
acupuncture can assist with muscle
dysfunction and pain management .
There are many medications that can
assist with chronic pain management
including but not limited to
Nonsteroidal Anti-inflammatories
(NSAIDs), Gabapentin, Amantadine,
and Ketamine.
Naltrexone has historically been used
for medication-assisted treatment of
alcoholism and opioid use disorders.
However, low-dose naltrexone (LDN) is
more recently being used in human
medicine as a novel treatment for
chronic inflammatory type pain. It is
currently being researched in human
medicine for reducing the severity of
symptoms in conditions such as
fibromyalgia, chronic regional pain
syndrome, multiple sclerosis (MS),
Chron’s disease, and cancer.
Naltrexone is an opioid receptor
antagonist and when used at low
doses has the ability to provide
analgesia and anti-inflammatory
actions.

The complete mechanisms of action
of naltrexone are not completely
understood in human medicine but is
thought to have an effect on:
1. Microglial cells which play a
negative role in inflammation
2. Temporarily blocking opioid
receptors may result in an
increased production of the
body’s own endorphins
(endogenous opioids).
In human patients, it is being shown to
help reduce chemotherapy related
side effects, improve quality of life,
assist with disease reduction, and
prolong survival times with certain
types of cancer. In veterinary
medicine, it has been investigated
with respect to improving quality of
life and survival times of dogs with
mammary cancer.
In human medicine, there are no
known reported serious concerns or
known abuse potential. Naltrexone is
not given in conjunction with opioids.
It is not a “quick acting” medication
and often takes a trial period of 4-8
weeks before improvement is noted.
If you are concerned about your pet’s
level of discomfort or mobility, physical
well-being, or their recovery process;
please speak to a rehabilitation
veterinarian.

https://pubmed....../33504322/

https://www.sci.....5811002708

https://www.sci.....3321000206

https://www.sci.....6920306585

https://www.sci.....6918302315