Page 109 - Withrow and MacEwen's Small Animal Clinical Oncology, 6th Edition

88 PART I The Biology and Pathogenesis of Cancer

TABLE 4.5 Selected Observational Studies of Canine and Feline Cancers by Type of Exposure—cont’d
Exposure Main Findings Strengths/Limitations
VetBooks.ir Pesticides

Any use of chemicals containing 2,4-dichlorophenoxyacetic acid (2,4-D)
63
Hayes, 1991
cases; high participation rates among cases and con-
positively associated with canine malignant lymphoma, compared with Strengths: Complete ascertainment of newly diagnosed
no use. Lymphoma risk increased with greater number of applications trols; collected extensive information on chemical use on
of 2,4-D–containing chemicals. lawns/yards (self-applied and commercially applied).
Limitations: One control group composed of dogs with other
cancers. note: This and other limitations were addressed
in subsequent analyses.
Glickman, Residence location within one mile of a marsh (where chemicals Strengths: Collected information on numerous sources
1989 65 were used for mosquito control) positively associated with of chemical exposure, including residential location to
canine TCC of the urinary bladder. Receiving flea dips more than industries, pesticide use, flee/tick treatments.
two times/year versus no use was positively associated with TCC. Limitations: 45% of control dogs had malignant neoplasia;
information was not collected on individual dog exposure
to the marsh or on specific chemicals used around the
house/yard.
Glickman, Access versus no access to phenoxy herbicide–treated lawns/yards posi- Strengths: Collected information on brand name and active
2004 44 tively associated with TCC of the urinary bladder among ingredients for household, lawn, and garden chemicals;
Scottish terriers. No association was observed for lawns/yards results were specific for phenoxy herbicide exposure.
not treated with phenoxy herbicides. Limitations: Limited statistical power to conduct subgroup
analyses.
Raghavan, Use of topical flea/tick products (e.g., shampoos, dips, powders, sprays, Strengths: Collected detailed information on use of flea/tick
2004 111 and collars) not associated with TCC of the urinary bladder among products (e.g., type, brand, pattern of use)
Scottish terriers. Limitation: 24% of control dogs had cancer; numbers for
cases and controls were not presented by exposure
level.
Environmental Pollutants
Bettini, 2010 112 Pulmonary anthracosis (high versus none) positively associated with Strengths: Histologic confirmation of primary diagnosis of
canine lung cancer risk. lung cancer; exposure assessment determined by histo-
logic scoring of anthracosis; strong biologic mechanism
supporting the a priori hypothesis.
Limitations: Small number of cases limited the statistical
analyses.
Marconato, Living in geographic areas exposed to toxic waste positively associated Strengths: Population-based study design, histologic
2009 43 with canine cancer risk (all tumors and lymphoma), compared with confirmation of cases; odds ratios were adjusted for age,
living in an unexposed area. No associations observed for canine sex, and breed.
mast cell tumors, canine mammary cancer, or feline cancers. Limitations: Same eligibility criterion (i.e., living at same
address for 2 years before enrollment) was not applied
to controls.
Gavazza, Living in an industrial neighborhood was positively associated with Strengths: Histopathologic or cytologic confirmation of
2001 66 canine lymphoma risk, compared with living in any other neighborhood. cases; information was collected on potential confound-
Use or storage of paints and solvents was positively associated ers.
with lymphoma risk, compared with no use of chemicals. Limitations: Very low prevalence of exposed cases and
controls; only univariate analyses were conducted.
Bukowski, Cumulative kerosene or coal heat exposure was positively associated Strengths: High participation rate; covariate information
1998 113 with sinonasal cancer risk. was compared between respondents and nonrespon-
dents; histopathologic confirmation of cases.
Limitations: Use of controls with cancer.