Evidence of a chemopreventive effect of progestin unrelated to ovulation on reproductive tract cancers in the egg-laying hen.

Published

Journal Article

Epidemiologic, laboratory, and animal evidence suggests that progestins and vitamin D may be potent ovarian cancer preventives. Our objectives were to evaluate progestins as reproductive tract cancer chemopreventives in the chicken, determine whether restricted ovulation affected the incidence of reproductive tract tumors, and assess whether vitamin D would confer cancer protection either alone or in addition to progestin. A total of 2,400 two-year-old Single Comb White Leghorns were randomized into six groups (400 each) with hormonal and dietary manipulation for 2 years as follows: (i) no intervention, regular feed/caloric intake, (ii) control, (iii) vitamin D, (iv) the progestin levonorgestrel, (v) vitamin D plus levonorgestrel, and (vi) the progestin Provera (medroxyprogesterone acetate). Groups 2 to 6 were caloric restricted to inhibit ovulation. Our results indicated that caloric restriction decreased egg production by more than 60%, and was associated with a greater than 70% decrease in reproductive tract cancers. Ovulatory events did not differ among the caloric-restricted groups (groups 2-6), except for the group receiving levonorgestrel, which had fewer ovulatory events than controls (P = 0.046). After correcting for egg production, birds receiving progestins had significantly fewer reproductive tract cancers [OR, 0.61; confidence interval (CI), 0.39-0.95; P = 0.03], with similar proportionate reductions in tumors arising in either the ovary or oviduct. Vitamin D did not significantly affect cancer incidence overall, or add to the cancer preventive effect of progestins. This study suggests a protective effect of progestins against ovarian and oviductal cancers. These data support the concept that progestins provide a chemopreventive effect unrelated to ovulation.

Full Text

Duke Authors

Cited Authors

  • Rodriguez, GC; Barnes, HJ; Anderson, KE; Whitaker, RS; Berchuck, A; Petitte, JN; Lancaster, JM; Wenham, RM; Turbov, JM; Day, R; Maxwell, GL; Carver, DK

Published Date

  • December 2013

Published In

Volume / Issue

  • 6 / 12

Start / End Page

  • 1283 - 1292

PubMed ID

  • 24136864

Pubmed Central ID

  • 24136864

Electronic International Standard Serial Number (EISSN)

  • 1940-6215

Digital Object Identifier (DOI)

  • 10.1158/1940-6207.CAPR-12-0426

Language

  • eng

Conference Location

  • United States