Use of genetic strains of chickens in studies of ovarian cancer.

Ovarian cancer is a deadly disease often diagnosed late in development when there is little chance for a successful recovery. Although ovarian cancer is a rare occurrence in most animals, the domestic hen has been shown to spontaneously develop the disease with an age-related incidence. Two strains of hens derived from a similar genetic background and maintained at Cornell University have been shown to differ in the incidence of the disease. At 2 yr of age, the C strain hens have a greater incidence of ovarian neoplasms than do K strain hens. Interestingly, levels of plasma estradiol are elevated in the C strain compared with K strain hens. In addition, plasma immunoreactive inhibin is lower in the C strain than in the K strain. Finally, mRNA expression of the alpha-subunit of inhibin in the granulosa cell layer of the large yellow follicles is lower in the C strain compared with the K strain hens. Further studies using these as well as other strains of hens may be useful in learning more about the etiology of this disease.