New research investigating a rare but aggressive cancer, histiocytic sarcoma, will be hugely beneficial to one of the UK’s native gundogs.
A UK study showed that more than 50% of Flatcoated Retrievers die of cancer, and the breed is particularly susceptible to histiocytic sarcoma. At the time of histiocytic sarcoma diagnosis, almost half of all affected Flatcoated Retrievers will have a tumour in multiple locations in the body. The outlook for these dogs is very poor and, in most cases, means they receive a terminal diagnosis.
Scientists at veterinary charity, the Animal Health Trust, in collaboration with the University of Cambridge, will undertake new research which ultimately hopes to enable the creation of a simple blood test to identify Flatcoated Retrievers with early stage histiocytic sarcoma. An early diagnosis would enable earlier investigation and treatment, improving the chances of successful treatment and of extending survival time.
Drs Dobson, Constantino-Casas and Sargan at the University of Cambridge have worked for many years with owners and breeders of Flatcoated Retrievers to define the cancer problem in the breed and to investigate its potential genetic basis. By way of a ‘Tumour Survey’ conducted over a period of 25 years, they have established an archive of tumour / tissue submissions of over 3,000 samples.
These, along with the information collected, have been invaluable in understanding the high incidence of histiocytic sarcoma within the breed to date and will provide a valuable source of tumour tissue for the new study.
Dr Anna Hollis, cancer researcher at the Animal Health Trust, said: “Histiocytic sarcoma is a particularly tricky cancer to diagnose, because the tumours are frequently located deep within or between the muscles of the upper limbs – underneath the shoulder is a common location.
“Often lame dogs are rested and given pain relief before imaging is sought. Delayed diagnosis is a potential problem with histiocytic sarcoma given its aggressive nature and ability to spread rapidly to other locations within the body. If we could identify affected dogs at an earlier stage, this may allow more successful treatment of the disease.”
The research project has been generously funded by the Flatcoated Retriever Society (FCRS) and the FCRS Rescue, Rehousing and Welfare Scheme. The Flatcoated Retriever Breed Health Co-ordinator, Liz Branscombe, who recently won the Kennel Club’s 2019 Breed Health Coordinator Award for her work in promoting breed health initiatives for Flatcoated Retrievers, said “The Flatcoated Retriever Society has regularly supported breed specific cancer research initiatives over the years. When we were told of plans by researchers at the Animal Health Trust and the University of Cambridge to instigate a pilot study to further understand histiocytic sarcoma we were keen to make a donation towards funding the project.
“Sadly, there is a high incidence of this aggressive form of cancer in our beautiful breed. Early detection of the disease is key in optimising cancer treatment and prolonging survival time so the prospect of a diagnostic blood test for use in the future is exciting.”
Dr Mike Starkey, Head of Cancer Research at the Animal Health Trust, said: “Cancer remains one of the biggest threats to the wellbeing of dogs, but through research we are making major strides forward in finding ways to beat it.”
What will this new research entail?
MicroRNAs are the focus of an exciting new field of cancer research. Abnormal levels of microRNAs are often found in tumours, and the microRNAs involved vary between different types of cancer. These cancer-specific microRNA ‘biomarkers’, or ‘signatures’, can even be found within the blood of cancer patients, meaning that the presence of a tumour could potentially be diagnosed by a simple blood test. Significantly, a previous research study undertaken by the University of Cambridge indicated that there may be a specific set of microRNAs whose levels are altered in histiocytic sarcomas in Flatcoated Retrievers, and that this is not found in other tumours and normal tissue.
To begin with, researchers plan to confirm if there is a specific microRNA ‘signature’ that is unique to histiocytic sarcomas amongst tumours and normal tissue samples from Flatcoated Retrievers. If such a signature is identified, the project will investigate if measuring the levels of these microRNAs within a Flatcoated Retriever tissue sample can be used to accurately identify a histiocytic sarcoma.
If a unique microRNA ‘signature’ is found in histiocytic tumours in Flatcoated Retrievers, additional funding will be sought to enable further research work to identify if the microRNA signature is also detectable in the blood of affected dogs. If such a microRNA signature is found in the blood of these dogs, this could potentially be identified via a simple blood test. This would mean that a blood sample from a Flatcoated Retriever that was lame, or was showing non-specific clinical signs of the disease such as depression, lethargy, appetite or weight loss, could be tested for the presence of the histiocytic sarcoma-associated microRNAs. A dog with a ‘positive’ test result could then have an early MRI scan and histopathology done to confirm the diagnosis, hopefully at a stage where treatment would be more successful. The ability to diagnose histiocytic sarcoma earlier could have a major beneficial impact on the management of histiocytic sarcoma in Flatcoated Retrievers.