Fat Tissue Delivers Chemotherapy Directly to Cancer Sites in Dog Study

First-Ever Use of MFAT Drug Delivery for Mesothelioma

This study explored a new way to deliver cancer-fighting medication using Lipogems® technology. Researchers treated a dog with mesothelioma—a rare and aggressive cancer affecting the lining of body cavities. They combined micro-fragmented adipose tissue (specially processed fat from the patient's own body) with a chemotherapy drug called paclitaxel. This created a delivery system that could release the medication slowly, right where the cancer was growing.

Mesothelioma is extremely difficult to treat in both dogs and humans. Most patients survive less than 18 months after diagnosis. Dogs develop this cancer naturally, making them valuable models for testing new treatments that might help humans too.

Treatment Delivered 17 Times Over Nearly Two Years

The six-year-old mixed-breed dog received treatments through ultrasound-guided injections into the chest and abdominal cavities. Each session involved:

• Draining fluid buildup from the chest and abdomen

• Injecting about seven milliliters of fat tissue loaded with chemotherapy

• Targeting both the abdominal cavity and both sides of the chest

Over 22 months, the dog received 17 treatments. Sessions were spaced an average of 38 days apart, ranging from two weeks to 70 days between visits.

No Serious Side Effects Reported During Treatment

One of the most encouraging findings was how well the dog tolerated the treatment. Monthly blood tests showed no abnormal results. The researchers observed no major short-term or long-term adverse effects. There were no signs of drug toxicity or allergic reactions—common concerns with traditional chemotherapy.

This safety profile matters because standard chemotherapy often causes significant side effects. The fat tissue appeared to protect the body from the harsh effects while still delivering the medication where needed.

Drug Stayed Local Rather Than Spreading Bodywide

Blood tests revealed that very little chemotherapy entered the bloodstream. The researchers measured drug levels at 30 minutes, two hours, four hours, and eight hours after the first treatment. They found low concentrations circulating through the body.

When they later tested tissue samples from the chest lining and the sac around the heart, they found the drug had remained in those areas. This "stay local" effect is important because:

• Higher drug concentrations at the cancer site may work better against tumors

• Lower drug levels in the bloodstream mean fewer side effects throughout the body

• The fat tissue acts as a slow-release system, extending how long the medication works

Dog Showed Long-Lasting Improvement in Health

Before treatment, the dog was weak, had lost appetite, was coughing, had a swollen abdomen, and struggled to breathe. After beginning the MFAT-paclitaxel treatment, the researchers observed long-lasting improvement in the dog's overall condition.

The treatment extended well beyond typical survival times for this cancer. While untreated dogs are often put down shortly after diagnosis, and treated dogs typically survive two to 13 months, this patient lived for at least 22 months while receiving treatment.

What This Means for Patients Exploring Options

This single-patient study represents the first time mesothelioma has been treated using fat tissue as a drug delivery system. While results from one dog cannot guarantee the same outcomes in humans, this research suggests a promising direction worth further investigation.

The approach offers potential advantages over traditional chemotherapy: targeted delivery, fewer body-wide side effects, and the ability to treat hard-to-reach cancers in body cavities. The researchers recommend additional studies to confirm these findings and explore whether this method could help with other tumor types.

If you have mesothelioma, discuss all available options with your oncologist. This study provides early evidence that MFAT-based drug delivery is safe and feasible, but more research is needed before it becomes a standard treatment option for humans.

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Source: Zeira et al., Frontiers in Veterinary Science, 2021.