Genetic and environmental risk indicators in canine non-Hodgkin's lymphomas: breed associations and geographic distribution of 608 cases diagnosed throughout France over 1 year.
BACKGROUND
The etiology of non-Hodgkin's lymphomas (NHL) is multifactorial. Environmental and genetic factors are frequently incriminated both in humans and dogs.


OBJECTIVE
Our purpose was to study the geographic distribution of canine NHL (CNHL) in France and to evaluate genetic and environmental influences.


METHODS
Six hundred and eight cases of CNHL, diagnosed throughout France over 1 year, were collected from 7 Veterinary Histopathologic Laboratories.


METHODS
Retrospective study. Breeds affected by lymphomas were compared with the national population and associations between breed and immunophenotype were studied. The distribution of CNHL and canine T-cell NHL per 100,000 dogs per department was compared with the distribution of waste incinerators, polluted sites, and radioactive waste.


RESULTS
The breeds significantly overrepresented among lymphoma cases were Boxer, Setter, and Cocker Spaniel (P < .001). There was a significant association between Boxer and T-cell NHL (P < .001), and between German Shepherd and Rottweiler and B-cell NHL (P < .01). The geographic distribution of CNHL and canine T-cell NHL indicated significant heterogeneity. Significant association between distributions of CNHL and waste incinerators (rho= 0.25, P < .05), polluted sites (rho= 0.36, P < .001), and radioactive waste (rho= 0.51, P < .001) was found.


CONCLUSIONS
Influence of genetics in the development of CNHL was supported by the existence of an association between breed and immunophenotype. Waste incinerators, polluted sites, and radioactive waste could just be considered as risk indicators of CNHL, but not as risk factors. Case-control studies around critical sites are necessary to confirm the implication of those environmental factors in the development of CNHL.
Pastor
M
M
Unité de Médecine Interne, Ecole Nationale Vétérinaire de Lyon, Université de Lyon, 69280 Marcy l'Etoile, France. m.pastor@vet-lyon.fr
Chalvet-Monfray
K
K
Marchal
T
T
Keck
G
G
Magnol
J P
JP
Fournel-Fleury
C
C
Ponce
F
F
D000818:Animals; D004283:Dog Diseases / Q000453:epidemiology* / Q000235:genetics; D004285:Dogs; D004777:Environment; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D016130:Immunophenotyping; D016393:Lymphoma, B-Cell / Q000453:epidemiology / Q000235:genetics / Q000662:veterinary*; D016399:Lymphoma, T-Cell / Q000453:epidemiology / Q000235:genetics / Q000662:veterinary*; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors