January 14, 2020 – Histiocytic sarcoma (HS) is an uncommon but aggressive cancer of dogs. Golden retrievers have a higher incidence of developing HS. Among Golden Retriever Lifetime Study dogs, there are nine cases of histiocytic sarcoma.
Histiocytes are a type of white blood cell that reside within the tissues of almost every organ in the body and are an important part of the immune system. They help get rid of invading pathogens and stimulate other cells of the immune system.
Histiocytic sarcomas develop when these specialized white blood cells begin dividing uncontrollably. Because they are found in lots of different tissues, they can arise almost anywhere and spread quickly.
Histiocytic sarcoma was first described in Bernese Mountain Dogs in the late 1970s but it’s now noted in many other breeds of dogs including flat-coated retrievers, miniature schnauzers, rottweilers, Labrador retrievers, Pembroke Welsh corgis and golden retrievers.
Histiocytic sarcoma is more common in middle-aged or older dogs although there are reports of the disease in dogs as young as three years old. Males and females are affected equally.
Histiocytic sarcoma can take many forms and clinical signs and prognosis varies with different subtypes. There are three recognized subtypes: localized, disseminated and hemophagocytic.
- Localized HS is confined to one organ and is usually treated with surgery followed by chemotherapy. In many cases, patients can live more than one year (and occasionally longer) depending on the success of the surgery.
- Disseminated HS affects many different organs. Chemotherapy can be used to slow progression of disease but prognosis is poor, with most patients only living a few months.
- Hemophagocytic HS is the most aggressive subtype. There are no effective treatments and survival times are only one to two months.
There is evidence that a genetic component may play a role in HS. The only other risk factor identified to date is a history of orthopedic disease and inflammation when HS is localized to a joint.
The Golden Retriever Lifetime Study cohort might provide valuable clues to understanding more about the genetics of this disease, particularly in golden retrievers. As we open our data and samples for use by researchers around the world, we hope that veterinary scientists will unlock the secrets of this deadly disease and help improve the lives of all dogs afflicted by histiocytic sarcoma.