Prostacyclin and its stable analogues have been shown to interfere specifically with certain steps of the metastatic cascade. The antimetastatic activity of the stable
prostacyclin analogue
Cicaprost (Schering AG) on haematogenous
metastasis in a series of tumours in rats and mice has been well established. In order to test the effect of
Cicaprost on lymphogenous
metastasis we chose the metastatic cell clone MTLn3 derived from the 13762NF rat mammary
carcinoma. The effect of
Cicaprost on prevention of lung
metastasis, lymph node metastasis and primary tumour growth was investigated.
Cicaprost given in daily doses of 0.01, 0.03 and 0.1 mg/kg orally, reduced the number of lung
metastases in a dose-dependent manner. Whereas the median number of lung
metastases in the controls was greater than 1000,
Cicaprost at a dose of 0.1 mg/kg reduced the number of lung
metastases to between 11 and 100. The weight of the ipsilateral axillary lymph nodes was diminished by
Cicaprost to 30-50% of controls. Moreover,
metastasis to the contralateral axillary lymph node was completely inhibited by
Cicaprost at all three doses tested.
Cicaprost did not influence the growth rate of the MTLn3 cell clone implanted into the mammary fat pad or the weight of the primary tumour at the end of treatment. In conclusion, in addition to its dose-dependent effect on haematogenous
metastasis,
Cicaprost strongly inhibits
lymph node metastasis.