Abstract: The invention relates to a gaseous composition containing xenon as active ingredient for use in preventing or limiting tumour cell migration and/or limiting or preventing metastasis formation in an individual suffering from cancer. The prevention or limitation of tumour cell migration is obtained through the action of the xenon on free cancer cells. The xenon acts on the free cancer cells carried by the blood. The effective volume proportion of xenon is between 5% and 79%, it is preferably at least 50%. The gaseous composition also contains a volume proportion of oxygen (O2) of at least 21%. It is administered by inhalation or insufflation.

Abstract: The invention relates to a liquid formulation including a liquid solution and at least one gas selected from xenon, argon, hydrogen, H2S, helium, krypton, neon, radon or CO, said gas being dissolved in said liquid solution, for the use thereof as a preservative solution for preserving biological material, in particular cells, tissue and biological organs, in particular an organ selected from the heart, the kidney, the liver, the pancreas and the intestines. The gas is preferably argon.