Effects of triple therapy with octreotide, galanin and serotonin on liver metastasis of human colon cancer in xenografts.

Human colon cancer cells (SW 620) were implanted under the capsule of the left liver lobe of female nude (C57BL/6JBom-nu) mice. After 7 days, relaparatomy was performed and an ALZET osmotic pump was implanted intraperitoneally and left in situ for 14 days. The mice were divided into 2 groups, 10 in each. The first group received 40 micro g/kg body weight of octreotide, galanin and serotonin, and the second group received sterile saline. The number of metastases in the liver, and to the intra-abdominal lymph nodes was significantly greater in the controls. The incidence of metastases to the peritoneal cavity was lower in the treated animals (though not statistically significantly). Tumour volume, wet weight, proliferation index and number of tumour blood vessels decreased significantly in the treated animals. The apoptotic index was significantly higher in the treated mice. The decrease in the volume and weight of tumours following the triple therapy seemed to be caused by low proliferation, and increased apoptosis, and reduced vascularization of the tumours. The low invasion of cancer cells observed following this treatment could have been due to the low tumour burden, and to the reduced number of the blood and lymph vessels.