The Organ Distribution of Disseminated 51Cr-labeled Tumor Cells1

The present study was undertaken to obtain quantitative data relative to the deposition and egress of neoplastic cells from organs following their hematogenous dissemination and subcu taneous inoculation. MCr-labeled Walker tumor cells in the rat and similarly tagged Brown-Pearce and V2 carcinoma cells in the rabbit were employed. Preliminary investigation confirmed the efficacy of this isotope technic for such studies. Following jugular vein or intraportal injection, the residence of a vast majority of the living tumor cells in the lung or liver was transient, contradicting the common belief that most circu lating cells lodge in the first organ encountered. The difference in the ability of the Brown-Pearce and V2 tumor cells to traverse the lungs was quantitated. Cells from the latter tumor less read ily left this organ 24 hr following inoculation of 10 X IO6 cells. Liver, kidney, spleen, and gastrointestinal tract, in decreasing order, were recipients of most of the cells which traversed the lungs. Distribution to brain, lymph nodes, and endocrine organs was considered insignificant. Subcutaneous inoculation of tumor cells in the legs of animals was followed by a rapid egress of cells from the injection site to other organs. These studies lend further support to the obsolescence of the concept that tumor distribution is related to mechanical con siderations or soil factors. In all probability, patterns of tumor spread are dictated by anatomic considerations as well as in trinsic factors in the tumor cell and the tissue it reaches.