Functionality of circulating DNA: the hypothesis of genometastasis.

The detection of free, circulating tumor DNA in the plasma of cancer patients opens up new possibilities for the diagnosis and prognostication of cancer. Whatever might be the mechanism for the presence of such DNA, it is now clear that oncogenes can circulate in the plasma fraction of blood and we can now ask whether this phenomenon has potentially important implications in cancer patients. The results of our experiments, together with previous observations of other authors, have led us to propose the "Hypothesis of Genometastasis", which suggests that metastases might develop as a result of transfection of susceptible cells in distant target organs with dominant oncogenes that circulate in the plasma and are derived from the primary tumor.