[Experimental study of liver regeneration and tumor growth following partial hepatectomy]

An experimental study was performed aiming to clarify the mechanism of early recurrence of hepatocellular carcinoma following hepatectomy. AH109A ascites hepatoma cells were implanted in a liver or subcutaneous tissue of male Donryu rats 5 days prior to 70% partial hepatectomy (H group) or simple laparotomy (L group) or non operation control (C group). Rats were sacrificed at 1, 3, 7 postoperative days. Tumor size, labelling index (LI), tissue blood flow (TBF) and regeneration rate of the remnant liver were measured. Tumor size of the remnant liver in hepatectomy group was 492 +/- 117 mm3 against 129 +/- 63 mm3 in laparotomy group showing enhancement of tumor growth following partial hepatectomy with statistical significance (p < 0.01). On the contrary, there was no difference in the growth of subcutaneous tumor among H, L, C group. A significant increase of LI in both liver and subcutaneous tumor cells comparable to regenerating liver cells at 24 hours after hepatectomy was observed in H group. It suggests that some humoral hepatotrophic factors increased DNA synthesis of not only tumor cells but liver cells. TBF in the tumor and remnant area of the liver were increased. This result supports that increased hepatotrophic factors and TBF led to the enhancement of tumor growth in the remnant liver following partial hepatectomy.