Effect of leukopenia and leukocytosis on tumor growth and survival time.Part I. Leukopenia

Abstract

The study was performed with 174 rabbits to determine the effect of leukophoresis and the resulting leukopenia on tumor transplant, growth, and survival time using the V2 carcinoma in the rabbit. Definite inhibition of tumor growth, together with increase in survival time, was found when leukophoresis was performed 7‐28 days after transplant as evidenced by an increase in survival time of 314 days in the entire group receiving 2 leukophoreses following transplants and 347 days in subgroups of those receiving 3 leukophoreses following transplants (but on days 7‐14‐21 or 14‐21‐28) vs. 73 days for the controls. The tumor growth rate paralleled the survival time and following transplant and leukophoresis, the increase and decrease of leukocytes paralleled the rate of tumor growth and retardation, respectively. There is reason to believe that the granulocyte may be more implicated than lymphocyte in tumor inhibition and survival time although so far experimental evidence has been on the side of the latter. A chance observation that leukophoretic plasma injected into cancerous and noncancerous animals produced marked leukocytosis, indicating a leukocytosis‐inducing factor, will serve to investigate any significant effects of leukocytosis on tumor growth and survival time and any possible interrelationship of leukopenia/leukocytosis to tumor inhibition and immunosuppression in Part II of this paper.

Leucopoietic Properties of Four Different Androgenic Hormones in Irradiated Rats

“…The androgenic hormones influence leucopoiesis in irradiated bone marrow to different degrees (Horn 1971, Horn et al 1968, 1971. The existence of a circulating humoral factor, the leucolcytosis inducing factor has been described but its action is still not clear (Bierman et al 1962, Craddock et al 1956, Gordon et al 1960, Morley et al 1970, Scott et al 1970, Sodicoff et al 1968, Steinberg et al 1965. The effect of androgenic hormones on the leucopoiesis was discussed in a p r e vious paper (Horn & Robinson 1971).…”