THE ANTIMETASTATIC EFFECT OF INTRAVENOUSLY-INOCULATED BCG ON PROSTATETUMOR-CELLS

The complication of metastasis from the primary tumor site to the dist ant organ is difficult to control. Tumor cells usually spread through the vascular system: lymphatics and/or blood; or by direct extension i nto adjacent sites. Transplantable prostate adenocarcinoma (PA-III) ce lls in L-W rats produces a tumor in the implant site and then spreads via the ipselateral lymphatic route to the lungs in which new visible tumors develop. Viable bacillus Calmette-Guerin (BCG) was inoculated S C or IV into rats which were then inoculated either SC or IV with PA-I II cells. They were examined thereafter for primary and for lung tumor s. IV-inoculated BCG generated a strong intravascular intervention mec hanism on metastatic PA-III cells in L-W rats. This immobilization mec hanism was not demonstrable in rats that had been inoculated SC with B CG.