OSTEOSARCOMA IN THE IRISH WOLFHOUND
The Animal Health Trust (AHT) is a unique charity; an independent, highly professional institute which undertakes pioneering work in the fields of veterinary research, clinical veterinary medicine and education. It has been making an outstanding contribution to improving the health and welfare of companion animals for over 60 years.
Irish Wolfhounds and Cancer
Osteosarcoma is the most common bone cancer of dogs, and in 2006 a Kennel Club/British Small Animal Veterinary Association Purebred Dog Health Survey reported that it was the most common cause of death in Irish Wolfhounds.
With the support of The Irish Wolfhound Society and The Irish Wolfhound Club and their members, since June 2005 we have been collecting samples from Wolfhounds to enable a study of the genetics of this disease. At present, we have collected samples from 212 Wolfhounds, including 36 from dogs with osteosarcoma.
Osteosarcoma is a tumour found particularly in the long bones of the legs close to the joints, such as by the stifle, or close to the shoulder joint. The early signs of the cancer are lameness and pain (which may be intermittent), limb swellings and fractures at the tumour site. Currently treatment for this disease is surgery plus anticancer drugs to deal with the spread from the primary. Life expectancy without treatment varies from a few weeks to 3-6 months. However, 40-60% of dogs that do receive chemotherapy survive for 12 months, and indeed half of these survive long term.
Cancer Research
The best way to treat cancer is to try to understand more about what triggers the disease in the first place. The Oncology Research Group applies a multidisciplinary approach to the study of a number of canine and feline cancers that are common and of considerable welfare importance. The group combines the expertise and experience of clinicians, pathologists, epidemiologists, molecular geneticists and statisticians to address the multifaceted nature of cancer and expedite cancer research at the AHT. The Group only uses tissue left over from clinical investigations, never taking tissue especially for research. The objectives of the research work are varied, but include developing tests that are better able to detect tumours at an early stage, or predict how a cancer in an individual animal will behave and respond to treatment, identifying the underlying causes of cancer, and developing and optimising new cancer treatments.
We wish to identify the genes that, when defective, are associated with the increased risk of Wolfhounds developing osteosarcomas. In the long term, we hope that the research will lead to the development of tests to identify dogs that carry the gene mutations conferring an increased risk, allowing breeders to take this into consideration in their breeding programmes. A realistic objective would be to attempt to reduce the incidence of dogs affected with osteosarcoma. Identification of 'osteosarcoma susceptibility genes' will also improve our understanding of how these tumours develop, thereby ultimately assisting the development of new therapies.
Irish Wolfhounds and Cancer Research
A specific example of the AHT's cancer research is a study to identify the gene mutations that are associated with the increased risk of Irish Wolfhounds developing osteosarcomas. In the long term it is hoped that the research will lead to the development of tests to identify dogs that carry the gene mutations conferring an increased risk, allowing breeders to take this into consideration in their breeding programmes. A realistic objective would be to attempt to reduce the incidence of dogs affected with osteosarcoma. Identification of 'osteosarcoma susceptibility genes' will also improve understanding of how these tumours develop, thereby ultimately assisting the development of new therapies.
For a conventional genetic study, approaching 100 samples from both affected and non-affected dogs are likely to be required. However, as it became apparent that we were unlikely to be able to collect this number of samples from Wolfhounds with osteosarcoma in the foreseeable future we decided to try an alternative novel approach of genetic analysis, which requires a much smaller number of samples.
In July 2008, the AHT Oncology Research Group was successful in an application to the United States-based Morris Animal Foundation for £29,400 to undertake a one year study to attempt to locate osteosarcoma susceptibility genes in the Irish Wolfhound. In the course of the study (which started in September 2008) the Group will identify the genetic markers present at 22,000 positions across the 39 dog chromosomes in DNA samples from each of 28 Wolfhounds with osteosarcoma (referred to as 'affected dogs') and 20 Irish Wolfhounds (known as 'control dogs'). The aim is to identify combinations of genetic markers (known as 'haplotypes') that are shared by all the Wolfhounds with osteosarcoma and not by the control dogs. If such markers are identified they are likely to be located in the same regions of the chromosomes concerned as the genetic defects that increase the risk of developing osteosarcomas.
Unfortunately, so far it has not been possible to identify genetic markers that are only present in the DNA samples from dogs with osteosarcoma. Therefore, it is likely that we will need to pursue our original plan of comparing DNA samples from around 100 Wolfhounds with osteosarcoma and an equal number of samples from Wolfhounds (aged 6 or above) who have never had cancer. The 'genetic profiles' already derived from the DNA samples from the 28 affected Wolfhounds and 20 control dogs will be re-analysed in combination with additional genetic data that we will generate from DNA samples that we will hopefully be able to collect from additional affected and control Wolfhounds.
How Irish Wolfhound owners can help
If you would like to submit a sample for this study, please refer to the details of how you can help that follow below. In addition, if you have previously submitted a sample for this project and your dog has subsequently developed cancer, please notify Lisa Jeffery (contact details below) at the AHT.
Thank you for your continued help and support.
Dr Mike Starkey
Oncology Research Group
June 2009
Irish Wolfhound owners can help this project as follows:
A) If your dog has a suspected osteosarcoma:
If your vet is taking a blood sample for a clinical reason, ask the vet to save a surplus sample (1-2ml) in an EDTA tube
OR
Contact the AHT (contact details below) to request a cheek swab kit.
Ask your vet to collect a small piece (3-5mm cube) of the biopsy of the suspected tumour (normally removed for diagnostic histopathology) and send it to the AHT.
If you have advance notice of your vet removing a biopsy, contact the AHT (contact details below) to ask for a special preservative ('RNAlater'), in which to collect the small piece of tissue, to be sent to the vet
OR
Ask your vet to place a small piece of the biopsy of the suspected tumour in a freezer, and then ask the vet to contact the AHT (contact details below) to ask to be sent a special solvent ('QIAzol') in which to transport the piece of tissue
B) If your dog does not have cancer (and has not had cancer) and is at least 6 years old:
If your vet is taking a blood sample for a clinical reason, ask the vet to save a surplus sample (1-2ml) in an EDTA tube
OR
Contact the AHT (contact details below) to request a cheek swab kit.
Please let us know if your dog develops cancer within the next 4 years,
For any queries or more information about the project, please contact:
Dr Mike Starkey (Tel: 01638 555603) Website
To submit a blood sample, or request a cheek swab kit
and/or an RNAlater/QIAzol sample tube (for a tumour biopsy), please contact:
Lisa Jeffery (Tel: 01638 751000, extension 1214)
This study is supported by the Irish Wolfhound Health Group