Liver regeneration and tumor growth in the rat after partial hepatectomy.

Tumor growth of Yoshida sarcoma implanted in the remnant liver was studied in rats subjected to a hepatectomy. After 70 percent hepatectomy, the liver progressively regenerated and the total liver weight was reverted to by 10 days after the operation. Concomitantly with liver regeneration, tumor growth in the remnant liver was stimulated significantly, compared with that in the sham-operated liver. Incorporation of tritiated thymidine into tumor cells in the remnant liver was strikingly high and progressive, while that in the sham-operated liver was low and retained. Mitomycin C given to the hepatectomized rats was more effective against the tumor in the remnant liver than in the sham-operated liver. We conclude from this study that cancer cell proliferation in the remnant liver can be accelerated by the process of liver regeneration.