According to a recent article published in the Journal of Clinical Oncology, it doesn’t matter whether you are experiencing a planned or unwanted pregnancy, chemotherapy administered to pregnant women during second or third trimesters for the treatment of breast cancer appears safe for both the fetus and mother.
Since breast cancer diagnoses during pregnancy are uncommon, data involving treatment with chemotherapy during pregnancy is relatively scarce, and researchers must gradually build on existing data regarding this issue. While the biggest fear about receiving chemotherapy during pregnancy is harm or even death to the fetus, postponing treatment raises the risk that the cancer will become more advanced and is more likely to yield a poor prognosis. However, research continues to indicate that some chemotherapy regimens administered in the second and third trimesters may not only pose no threat to the growing fetus, but also optimize long-term outcomes for the mother.
Researchers from England recently reviewed records from 28 women who were diagnosed with breast cancer during pregnancy. All women were treated with chemotherapy in their second and third trimesters (except one who was treated during her first trimester). Chemotherapy consisted of anthracycline-based regimens (doxorubicin or epirubicin) or consisted of the regimen referred to as CMF (cyclophosphamide, methotrexate, 5-fluorouracil). Women received chemotherapy either prior to or following surgery. Seventeen patients underwent surgery during their pregnancy, while some patients underwent surgery following delivery. The majority of women had stages II and III breast cancer, and the average number of chemotherapy cycles delivered was four. Of the 27 patients who received chemotherapy during their second and third trimesters, no birth defects occurred. The one patient who received chemotherapy during her first trimester suffered a spontaneous abortion (miscarriage). The average weight of the babies was over 6 pounds and the average delivery occurred on the 37th week of pregnancy.
The researchers concluded that even though the group studied was small, these results add to a growing body of evidence that chemotherapy delivered during the second and third trimesters of pregnancy does not appear to harm the fetus. Other results have indicated, however, that chemotherapy administered during the first trimester of pregnancy may pose significant risks to the fetus. Women who are diagnosed with breast cancer during pregnancy should discuss their individual risks and benefits of treatment including chemotherapy with their healthcare provider.
Reference: Ring A, Smith I, Jones A, et al. Chemotherapy for Breast Cancer During Pregnancy: An 18-Year Experience From Five London Teaching Hospitals. Journal of Clinical Oncology 2005;23: 4192-4197.