[Experimental study on tumor growth in the regenerating liver]

The purpose of this study was to investigate the effect of liver regeneration on the growth of liver tumor. VX2 carcinoma was transplanted in the liver of New Zealand white rabbits, and 40% partial hepatectomy was performed. The following results were obtained. 1. After 40% partial hepatectomy VX2 carcinoma was transplanted in the remaining liver. Two weeks later, the tumor volume was larger in partially hepatectomized than in shamoperated rabbits (p less than 0.01). 2. When 40% hepatectomy of rabbits which carrying VX2 carcinoma transplanted 2 weeks previously was performed, the mitotic index of the tumor at 24 to 36 hours was significantly higher in hepatectomized than in sham-operated rabbits (p less than 0.02). At 24, 36, 48 hours after partial hepatectomy, the mitotic index of the hepatocytes of the hepatectomized group was significantly higher than that of sham-operated group (24 hrs.: p less than 0.005, 36 hrs.: p less than 0.01, 48 hrs.: p less than 0.005). 3. At 36 hours after partial hepatectomy there was a significant increase of DNA synthesis in tumor cells as compared with that in sham-operated controls (p less than 0.05). These data indicate that liver regeneration enhances the tumor growth in regenerating liver.