Growth of primary explants of human cancer in newborn rats

Suspensions of human cancer cells were prepared from surgical specimens or effusions and were transplanted into rats by 2 techniques. Thirty specimens were transplanted by intravenous inoculation of single cell suspensions containing one to 5 million cells before the rats were 24 hours old. Five of these specimens produced tumor nodules in lungs and sometimes in other organs. One hundred twenty-six specimens were transplanted by subcutaneous or intraperitoneal inoculation of a crude suspension of cells and tissue fragments into young rats which had been made tolerant by intravenous injection of human tissue-cultured cells when they were newborn. Twenty-six of these produced subcutaneous or intraperitoneal nodules. All takes were confirmed by histologic study.