Abstract
Fetal cell microchimerism (FCM) is the persistence of fetal cells in the maternal circulation and organs following pregnancy. Proposed hypotheses about the function of fetal cells in the pathogenesis of maternal cancer include promotion of tumorigenesis, protection by providing immunosurveillance, and participation in tissue repair. To date, studies of FCM and cancer have been primarily descriptive and quantitative. More research is needed to understand the cellular phenotype of the microchimeric cells in maternal tumors and whether they have a functional role. This research will require further study using a multidisciplinary approach, incorporating knowledge of the fetomaternal relationship, tumor biology, immunology, and clinical oncology.