Comparison between triple therapy with octreotide, galanin and serotonin vs. irinotecan or oxaliplatin in combination with 5-fluorouracil/leukovorin in human colon cancer.

Human colon cancer cells were injected sub-cutaneously into 30 nude mice. After 8 days, the animals were divided into 3 equal groups. The first and second groups received an i.p. injection with 5-fluorouracil/leukovorin (5-FU/LV) for 5 days (20 mg and 10 mg/kg body weight respectively). On the first day of 5-FU/LV treatment, the first group received an i.p. injection of irinotecan (2.5 mg/kg body weight), and the second group received an i.p. injection with oxaliplatin (1 mg/kg body weight). The third group were injected i.p. with 100 microl saline solution containing octreotide, galanin and serotonin. Injections were given 3 times daily for 5 days with a total dose of 150 microg/kg body weight/day. Three days after the treatment, the animals were sacrificed. Whereas the animals treated with triple therapy held a stable body weight, animals treated with 5-FU/LV-irinotecan and 5-FU/LV-oxaliplatin had gradual weight loss, which amounted to approximately 25% of their body weight at the end of the experiment. Moreover, 2 mice in the group treated with 5-FU/LV-irinotecan died, most probably due to side effects. There was no statistically significant difference between the 3 groups regarding tumour proliferation, apoptosis, blood vessel density, EGF- and VEGF-expression. Treatment with triple therapy using octreotide, galanin and serotonin appear to be comparable to 5-FU/LV in combination with irinotecan and oxaliplatin. However, triple therapy seems to have a better safety profile.