Melanoma

Melanoma is a cancer of the pigment cells of the skin: the melanocytes. It is a very aggressive cancer that affects the skin, mucous membranes and the eye.

– In Humans, the incidence of melanomas is increasing in different parts of the world and is a major public health issue. Indeed, no method allows an early diagnosis, except surgery before extension and metastatic spread and to date no therapy is effective. Among the different of melanoma forms, the cutaneous form is the most fres, Its main risk factor is sun exposure, ocular and mucosal forms being more rare.

– In Dog, melanomas are frequent and affect many breeds, some of them being more frequently affected than others. Oral melanomas are by far the most frequent, and cutaneous and ocular melanomas are more rare. The sun is not a major risk factor. However, there are clearly racial predispositions specific to these different types of melanoma.

Human and canine melanomas show strong clinical, histological and treatment response analogies. Unfortunately, the genetic mechanisms involved in the appearance and development of these particularly aggressive cancers are still poorly understood in humans and dogs. This is why the team developed a study to search the genetic underlying the different types of melanoma in dog, in several predisposed breeds, in order to discover the molecular mechanisms that will be used for research in dogs and humans.

The breeds concerned by our study are the Poodle (mucous-type melanoma with oral location), the Labrador Retriever (cutaneous, ocular and mucosal melanomas with oral location), the Golden Retriever (melanomas of cutaneous and mucous type with oral location) and the Schnauzer (cutaneous melanomas with digitized localization). However, we are interested in all cases of melanoma and melanocytoma (benign tumors) regardless of race. For predisposed breeds, the goal is to collect blood samples, and if possible tumors and corresponding healthy tissue, for a hundred affected dogs and a hundred control dogs (old dogs without cancer).

Genetic analysis consist in the comparison of the genomes (DNA extracted from blood and tumors) of affected dogs to the genomes of unaffected dogs. This allows, after statistical analysis, the identification of chromosome regions that will be specifically linked to the disease and in which we may find genetic alterations implicated in the tumour onset and its development.

The results can then be used to :

  • identify prognostic factors and develop early screening tests, based on genetic risk factors in dogs,
  • transfer these data to human melanoma research.

We are looking for :

  • Affected dogs : all breeds, all ages
  • Unaffected dogs : old Poodles and Schnauzers (> 12 years old and no cancer), as well as Golden Retriever, Labrador Retriever and Rottweiler.

To participate in this research work, please send us:

  • a blood sample and a tumor sample :

melanomas CNRS_Melanome_Protocole

uveal melanomas CNRS_Melanome uvéaux_Protocole

  • the following questionnaire according to the type of melanoma:

melanomas CNRS_Melanome_Questionnaire

uveal melanomas CNRS_Melanome uvéaux_Questionnaire

  • a copy of the dogs’ pedigree (if possible and if available)
  • the histological report (if available)

This work is realized at the CNRS in Rennes, in collaboration with Dr. Patrick Devauchelle (Veterinary Cancer Center, ENV Alfort), Dr. Jerome Adabie (LHA, ENV Nantes), Dr. Jean-Pierre Jégou (Veterinary Ophthalmologist, Ophtanimal , Paris) and thanks to veterinary histopathology laboratories (LAPVSO, Toulouse and IDEXX Alfort), ONCOVET (Lilles) with the help of numerous veterinarians and thanks to the numerous owners and breeders who accept to sample their dog(s).

Examples of melanomas in dogs: 

  1. Cutaneous melanoma

Photo M. Delverdier

  1. Ocular melanoma

Photo M. Delverdier

  1. Oral melanoma

Photo M. Delverdier

We remind you that the data collected at the CNRS remain confidential.

For more information, you can contact the team by phone at 02 23 23 45 09 or by email cani-dna@univ-rennes1.fr.