Role of host endocrine status in murine leukaemogenesis.

Permanent changes in the endocrine status of female SJL/J and CR mice were induced by masculinization, ablation of endocrine glands, inoculation of hormones, or feeding of the chemical carcinogen DMBA. All these procedures resulted in modification of the host hormonal milieu, as shown by blood hormone determination. Masculinization reduced drastically the onset of lymphosarcoma and increased the incidence of systemic neoplasms respectively in DMBA-treated female SJL/J and CR mice. Continued administration of gonadotrophins increased the incidence of systemic neoplasia in CR mice. A direct correlation is suggested between onset of lymphosarcoma or other tumours in mice and a specific shift to an abnormal hormonal environment.