[Effect of age on the growth of transplantable tumors in mice]

Tumors of various histological patterns (squamous-cell carcinoma of uterine cervix SCC. Lewis lung carcinoma, hepatoma-22a, mammary adenocarcinoma-755, sarcoma-180 and hemocytoblastosis La) were transplanted in mice aged 3, 12-18 months. Tumor SCC, hepatoma-22a, sarcoma-180 and adenocarcinoma-755 grew faster in older animals (18 months) than in younger one (3 months), while Lewis lung carcinoma and hemocytoblastosis La developed at the same rate in old and young animals. It is suggested that tumor growth in senescent organism is determined by both hormono-metabolic shifts, degree of immunologic vigor and a number of biological characteristics of tumor.