Metastasis of maternal cancer to the placenta and fetus

The occurrence of metastasis of maternal cancer to the products of conception is numerically inconsequential but offers an opportunity for significant biological research into the behavior of cancer. More extensive investigation, both clinical and experimental, is necessary before any firm conclusions can be established. The surprisingly infrequent occurrence of this condition allows speculation that biological protective mechanisms may exist for the placentofetal unit. Circulatory or immunologic responses may play a role in this defense. The possibility of an intrinsic trophoblastic property achieving this result warrants investigation.