An experimental study of postoperative tumor metastases.I. Growth of pulmonary metastases following total removal of primary leg tumor

Abstract

ULTIPLE distant metastases sometimes a p M pear and grow rapidly after operations designed to extirpate primary cancers.This Occurrence is most common after amputation of an extremity in which there is osteogenic sarcoma, but rapid growth of metastases is not infrequent after surgical removal of other tumors.Despite lack of proof, there is a suggestion that surgical procedures may precipitate dissemination and growth of tumor in these instances.It is the purpose of t h i s study to evaluate the effect of removal of a malignant neoplasm on the growth of its distant metastases. MATERIAIS AND METHODSCXDBA hybrid and DBA strain mice were approximately 4 weeks of age at the time they were used in these experiments.The mice were housed in plastic cages and were fed Purina Laboratory Chow and given water ad libitum.S-91 melanoma and DBA sarcoma 49 were the tumors used in this study.S-91 melanoma originated in a strain DBA/l mouse.'The stock tumor grows only in strain DBA mice or hybrid derivatives thereof.DBA sarcoma 49 originated in a strain DBAf/2An mouse.2I t grows progressively in 90% of strain C mice as well as in DBA mice.S-91 and DBA 49 tumors were removed aseptically from the strains of mice in which they were maintained, and suspensions of cells were made by passing 1 gm. of solid tumor through a cytosieve.as described by Snell.8An inoculum of 0.05 ml. of a 1:lO dilution with normal saline was injected into the inferior portion of the posterior muscles of the hind leg of a mouse.Tumor takes were uniformly