title: Hormonal and sex impact on the epidemiology of canine lymphoma.
abstract: The Surveillance Epidemiology and End Results data demonstrate that the risk of non-Hodgkin lymphoma is lower for women, but that the incidence increases after fifty years of age, at which menopause is regularly reached, suggesting that female hormones may be protective for NHL. This study examines the influence of sex on lymphoma risk in a relevant large animal model. Records for dogs in the Veterinary Medical Database were analyzed from 1964 to 2002. Risk ratios were calculated to evaluate associations between sex, neutering status, and lymphoma occurrence. A total of 14,573 cases and 1,157,342 controls were identified. Intact females had a significantly lower risk of developing lymphoma, Odds Ratio 0.69 (0.63-0.74) with a P < .001. We conclude that there is a sex effect on NHL risk in dogs similar to humans. We hypothesize that the hormone levels of intact females lower the risk of NHL. The possibility of a protective role of endogenous estrogens in the etiology of NHL should be investigated.
authors.affiliation: Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO 65211, USA.
authors.forename: J Armando
authors.initials: JA
authors.lastname: Villamil
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Henry
authors.forename: Allen W
authors.initials: AW
authors.lastname: Hahn
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Bryan
authors.forename: Jeff W
authors.initials: JW
authors.lastname: Tyler
authors.forename: Charles W
authors.initials: CW
authors.lastname: Caldwell
references.citation: J Comp Pathol. 1997 Jul;117(1):35-59
references.pmid: 9263843
references.citation: Vet Clin North Am Small Anim Pract. 2007 Nov;37(6):1023-32; v
references.pmid: 17950880
references.citation: Nat Biotechnol. 2006 Sep;24(9):1065-6
references.pmid: 16964204
references.citation: Cancer Causes Control. 2002 Mar;13(2):131-6
references.pmid: 11936819
references.citation: PLoS One. 2008 Jun 30;3(7):e2816
references.pmid: 18636124
references.citation: Int J Cancer. 2007;120 Suppl 12:1-39
references.pmid: 17405121
references.citation: Cancer Res. 2005 Jul 1;65(13):5654-61
references.pmid: 15994938
references.citation: Cancer Epidemiol Biomarkers Prev. 2002 Nov;11(11):1466-71
references.pmid: 12433728
references.citation: Am J Epidemiol. 2008 Aug 1;168(3):278-88
references.pmid: 18550561
references.citation: J Natl Cancer Inst. 1959 Apr;22(4):719-48
references.pmid: 13655060
references.citation: J Am Vet Med Assoc. 1979 Jun 15;174(12):1301-3
references.pmid: 511727
references.citation: Bibl Haematol. 1970;(36):403-15
references.pmid: 5538360
references.citation: Cancer Invest. 2000;18(8):781-92
references.pmid: 11107448
references.citation: Am J Epidemiol. 2004 Oct 15;160(8):766-73
references.pmid: 15466499
references.citation: J Natl Cancer Inst. 1969 Dec;43(6):1249-61
references.pmid: 4319248
references.citation: Cancer. 1990 Aug 1;66(3):480-90
references.pmid: 2364361
references.citation: J Vet Intern Med. 2009 Mar-Apr;23(2):301-10
references.pmid: 19192140
references.citation: Vet Comp Oncol. 2007 Sep;5(3):133-44
references.pmid: 19754785
references.citation: Prostate. 2007 Aug 1;67(11):1174-81
references.pmid: 17516571
references.citation: Vet Pathol. 2006 May;43(3):241-56
references.pmid: 16672571