Preliminary report of tumor metastasis during liver regeneration after hepatic resection in rats.

In an attempt to ascertain possible facilitation of tumor metastasis during liver regeneration after hepatectomy, a series of experiments in rats was carried out using the RBT-1 carcinoma. WKA rats were separated into three groups: Group A received a sham operation; Group B underwent one-third hepatectomy; and Group C underwent two-thirds hepatectomy. Three groups had viable tumor cells injected into the tail vein after treatment. Survival period and lung metastases were analysed 14 days after initial injection of tumor. When comparisons were made between all groups, survival was shown to be significantly shorter in Group C than Group A (P < 0.05). The number of metastatic nodules in the lungs was significantly increased in Group B (P < 0.05) and C (P < 0.01), compared to Group A and in Group C, compared with Group B (P < 0.05). These results suggest that facilitation of tumor metastasis during liver regeneration may be proportional to the extent of liver resection.