Epidemiologic Study of Leukemia in Twins (1928-1969)

Abstract

SUMMARYA review of 62 cases of leukemia in twins reveals most cases occurred in MZ twins, although diagnosis of zygosity was at times admittedly questionable. Concordance was clearly highest in MZ twins of the perinatal-congenital period. This tendency was not maintained at later stages of life.The older concept of a human placental barrier has been greatly modified. Tracer substances have demonstrated that leukemic cells pass the placental barrier. Materno-fetal transmission of leukemia is well known; all forms of murine leukemia can be transmitted similarly from generation to generation. Certain requisites effect the transmission of neoplastic-hematopoietic disease during pregnancy. Rare cases are reported of pregnant women with leukemia who bear children in whom clinical leukemia subsequently develops. The maternal diagnosis was made at the time of, or shortly after, delivery, suggesting an evolution of the maternal disease late in pregnancy.That both partners of a pair of twins, either MZ or DZ, can become ill with leukemia within days or months of each other, appears more than coincidental. Chromosomal defects, common environmental factors, and conjoined intrauterine circulations may be important in the transmission of leukemia from one twin to another, a theory supported by the frequent concordance during the first year of life.