Fetal cell microchimerism in human cancers

The transfer of fetal cells into the maternal circulation occurs normally during pregnancy and the post-partum persistence of these cells in the maternal blood and tissues, known as fetal cell microchimerism, has been clearly demonstrated. However, the long-term consequences of this phenomenon are only beginning to be appreciated. In particular, whether microchimerism could be involved in the carcinogenetic process or whether fetal microchimeric cells could be able to differentiate in host tissues, participating in the maternal response to injury, is still matter of study. In this review, the possible role and the consequences of fetal cell microchimerism, as emerged from studies in animal models and in women with different types of cancer, will be presented.