Maternal malignancy during pregnancy is estimated to occur in 1 out of 1000 pregnancies. Controversy exists regarding the effect of pregnancy on cancer prognosis. Gestational hormones and pregnancy-related growth factors may induce a more aggressive behavior in malignant cells. However, metastasis to the products of conception is rare. In the current study investigators wish to analyze the effect of placental explants on cancer cells (cervical, ovarian, thyroid, melanoma, lymphoma, leukemia and breast)phenotype (cell death, proliferation, migration , invasion), signaling pathway, mRNA, miRNA and protein expression.