Chemotherapy delivered in the first trimester is associated with a 10% to 30% risk of abortion and 10% to 25% risk of malformations. Therefore, it should be postponed until the second or third trimester, when most regimens appear to be safe, according to Nicholas Pavlidis, MD, of the University of Ioannina in Greece, who is coauthor of Cancer and Pregnancy (Springer, 2008). At a lecture during the 2011 European Multidisciplinary Cancer Congress, Dr. Pavlidis offered his principles for safely giving chemotherapy to pregnant women:
- Medical oncologists should treat the mother and protect the fetus.
- Chemotherapy should not be allowed during the first trimester.
- Methotrexate should be avoided entirely.
- Endocrine therapy should also be avoided; tamoxifen has been associated with congenital defects in anecdotal reports.
- Targeted small molecules and monoclonal antibodies should be avoided due to lack of documented safety; trastuzumab (Herceptin) has been linked to an increased risk of maternal and fetal adverse outcomes.
- Risks associated with bisphosphonates are not clear, and therefore, they should be avoided.
Dr. Pavlidis referred oncologists to the recent recommendations of the European Society of Medical Oncology for the treatment of pregnant patients with malignancies.1 ■
Disclosure: Dr. Pavlidis reported no potential conflicts of interest.
Reference
1. Pentheroudakis G, Orecchia R, Hoekstra HJ, et al: ESMO Guidelines Working Group. Cancer, fertility and pregnancy: ESMO Clinical Recommendations for diagnosis, treatment and follow-up. Ann Oncol 21(suppl 5):v266-v273, 2010.
