Facilitation of tumor metastasis after hepatic resection in rats

In an attempt to ascertain for possible facilitation of tumor metastasis after hepatectomy, a series of experiments was carried out using the RBT-1 carcinoma.

The animals were separated into three groups: Group A, received no treatments, Group B, received a sham operation, and Group C underwent partial hepatectomy. Three groups had viable tumor cell injected into the tail vein after the treatment.

The mean survival periods in Group A, B, and C were 32.7, 28.8, and 24.8 days, respectively. When a comparison was made with all groups, survival time was significantly shorter in Group B and C than Group A (p < 0.01), and in Group C, compared with Group B (p < 0.05). Fourteen days after initial injection of RBT-1 tumor ten rats in each group were sacrificed and their lungs were assessed for evidence of metastatic spread of tumor. The mean number of metastatic nodules in Group A, B, and C were 5.1, 11.5, and 49.8, respectively. 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 < 0.01). The facilitation of metastasis by surgical treatment was examined in relation to serum adrenocortical hormones. After the treatment, serum corticosterone levels were transiently increased in Group B (p < 0.01) and C (p < 0.01), compared to Group A, and in Group C (p < 0.01), compared with Group B.

These results are taken to mean that facilitation of tumor metastasis after hepatectomy was possibly increased.