Malignant disease in pregnancy

Abstract

Cancers in pregnancy are uncommon but do occur with an average frequency of 1 in 1,000 births. This gives rise to opposing emotional reactions in these women: they are happy they are pregnant, but usually devastated when they hear they have cancer.

The major reasons for suspecting that pregnancy adversely affects the clinical course of cancer is the immunologic tolerance that characterizes both conditions. It has been pointed out that normal pregnancy and cancer are the only two biologic conditions in which the antigenic tissues is tolerated by a seemingly intact system. It may be stated that the mechanisms that insure the survival of fetus during pregnancy presumably also favors the progress of the neoplasia.

Management requires individualization with careful thought as whether termination is necessary or whether continuing with the pregnancy is possible prior to definitive treatment. The physician's aim must be to cure the cancer and deliver live, healthy infants. This is one question when a joint decision is probably best reached among the obstetrician, surgical and medical oncologists and other disciplines.

The life-threatening cancer should be managed both for the diagnosis and treatment as in the non-pregnant state. An early small cancer gives a better prognosis than an advanced cancer. The same holds for the non-pregnant patient. The survival in the non-pregnant patient stage for stage is the same as for the pregnant patient. However, all too often in the pregnant state the cancer is more advanced than in the non-pregnant patient. The disease must be evaluated and treated in full light of its exact location in conjunction with an understanding of the natural history within the context of the pregnancy with the potentially viable unborn infant.

Concern that maternal cancer may metastasize to the fetus is not justified from a review of the accumulated literature. Infrequency of fetal involvement has led to speculation about biologic protective mechanisms that may exist for the placenta and the fetus and the role circulatory separation in the placenta and immunologic responses of the fetus may play. The association of cancer in pregnancy represents a major physiologic process for the maintenance of the race and a major pathologic process that accounts for numerous deaths. It presents a controlled growth and an uncontrolled growth in the same host.