Although rare, cancer, including lymphoma, does occur in pregnant women. The effect of both the cancer and treatment on the fetus is a major concern to expectant parents, adding to the stress of dealing with a diagnosis of malignancy. Some types of anti-cancer treatment, such as the anti-folate drug methotrexate, are best avoided at all stages of fetal development, and the effects of other classes are likely dependent in part on the physical characteristics of each drug, which can affect the ability of each to cross the placenta. For example, certain anthracyclines, which are critical in the treatment of lymphoma and other hematologic malignancies, cross the placenta poorly, whereas others, such as idarubicin and liposomal formulations of doxorubicin, have physical characteristics which allow greater penetration into the fetal circulation.
Fortunately, evidence is mounting that exposure of the fetus to many common types of chemotherapy after the first trimester does not produce negative effects on normal development, either in terms of organ development or neurologic function. A recent study published in the Lancet Oncology observed children born to mothers that were treated for cancer and compared their physical, behavioral and cognitive development to established norms in similar populations. The authors found that children born to mothers that were exposed to chemotherapy for treatment of cancer after the first trimester did not show notable differences in development from children in the general population matched for other characteristics. Although the numbers were too small to compare different chemotherapy regimens in their effects, the general finding of no significant decrement in development in this prospective study was encouraging. Of note, the most powerful predictor of cognitive developmental delay was premature birth, comparable to that seen in children born prematurely for other reasons. Although it is not possible to definitively rule out an additional effect of chemotherapy in this group, this finding argues that “iatrogenic prematurity,” or delivery of a baby before term for purposes of treating the mother’s cancer, is likely to be counter-productive, unless undertaken for a specific reason other than sparing the fetus exposure to chemotherapy.
Another critically important question involves the outcome of treatment for the patient. Pregnancy affects blood volume and could affect the body’s handling and metabolism of chemotherapy drugs. No large prospective studies are available to address this issue, but a presentation by Dr. Andrew Evens of the University of Massachusetts at the most recent meeting of the American Society of Hematology in December of 2011 showed excellent outcomes in a retrospective study of 88 women diagnosed with lymphoma during pregnancy. Weill Cornell Medical College participated in the study. Although the retrospective nature of the study and heterogeneity of the patients preclude definitive conclusions, this study provides more encouraging data for women facing a diagnosis of lymphoma during pregnancy. Click here to read the abstract.