Transplacental cancer transmission: a comprehensive review focusing on mechanisms, challenges, and maternal-fetal outcomes.

The phenomenon of transplacental transmission of cancer, where cancer cells pass from a pregnant mother to her fetus is an extremely rare occurrence. This phenomenon has significant implications for maternal and fetal health, challenging our understanding of cancer biology and maternal-fetal interactions. The literature on transplacental cancer transmission is sparse, consisting mainly of case reports, small cohort studies, and reviews. Examples of cancers that have been transmitted in this way include melanoma, choriocarcinoma, leukaemia, and lymphoma. Understanding this phenomenon is important because it has direct clinical implications for managing pregnant women with cancer and the infant, raises questions about the placental barrier and immune interactions between mother and fetus, and offers insights that could influence cancer biology and treatment strategies. This review aims to evaluate existing data, identify and synthesize evidence on transplacental cancer transmission cases, evaluate cancer types involved, their transmission mechanisms, and clinical outcomes for both mothers and infants. A comprehensive electronic search of databases was conducted for relevant case reports and series, using specific keywords related to vertical and transplacental transmission of cancer. The review elucidates comprehensive information from the reports to understand how cancer transmission occurred and was confirmed as vertical transmission, aiming to enhance knowledge in this critical area of maternal-fetal medicine.