Special Issues in Pregnancy
Summary of Key Points
• Cancer complicates 1 in 1000 pregnancies; the most common malignancies in pregnant women are breast, uterine, and cervical cancer, lymphoma, and melanoma.
• No evidence exists that pregnancy alters the clinical behavior of cancer, but cancer often is advanced at diagnosis because of the overlap of symptoms with those of a normal pregnancy.
• Important factors in management include assessment of gestational age, maternal staging with limited exposure to ionizing radiation, the urgency of therapy, and the impact of therapy on maternal prognosis and fetal outcome.
• Physiological changes in pregnancy affect the metabolism of chemotherapy drugs, but few practical guidelines exist about how dosing should be adjusted to take this factor into account.
• Alkylators and antimetabolites should be avoided in the first trimester, but these agents and other cytotoxic drugs are generally not contraindicated (with the possible exceptions of methotrexate and hydroxyurea) in the second and third trimesters.
• The scheduling of chemotherapy should be planned to minimize the risk of complications at the time of delivery.
• No evidence exists that exposure to chemotherapy results in long-term adverse effects on physical or intellectual development, and surviving children have no increased risk of malignancy.
• Therapeutic radiation jeopardizes fetal outcome and should be reserved for the postpartum period whenever possible.
• Subsequent pregnancy after cancer diagnosis and treatment is usually possible.
1. Malignancy in pregnancy affects:
2. Maximum fetal radiation dose exposure during pregnancy is:
3. A 38-year-old gravida 1, para 0 woman at 10 weeks’ gestation is diagnosed with a clinical T2N1 left-sided infiltrating ductal carcinoma that is estrogen receptor and progesterone receptor positive and HER2 positive. She wants to continue with the pregnancy and declines mastectomy but agrees to neoadjuvant chemotherapy. Treatment recommendations may include:
A Immediate chemotherapy with doxorubicin and cyclophosphamide
B Tamoxifen, because she is estrogen receptor/progesterone receptor positive
C Doxorubicin and cyclophosphamide beginning in the second trimester with consideration of sequential paclitaxel
D Doxorubicin and cyclophosphamide followed by trastuzumab beginning in the second trimester
4. The most common types of lymphoma and leukemia seen in pregnancy are:
A Burkitt lymphoma and acute lymphoblastic leukemia
B Diffuse large B-cell lymphoma and chronic myeloid leukemia
5. True or false: It is safe to use imatinib during pregnancy.
1. Answer: C. Cancer in pregnancy affects 1 in 1000 pregnancies and is the second leading cause of maternal death in the United States.
2. Answer: B. The American College of Obstetricians and Gynecologists has published recommendations for imaging during pregnancy that state that 5-cGy exposure to the fetus is not associated with any increased risk of fetal loss or birth defects. Radiation exposure is well below this for most procedures except for the maximum dose with computed tomography scanning of the abdomen and pelvis (Table 64-2).
3. Answer: C. Ideally, administration of chemotherapy should wait until the second trimester. Doxorubicin and cyclophosphamide with or without fluorouracil have the most data supporting safe use. Taxanes have limited data but appear safe in the second and third trimester and may be considered in cases where benefit is believed to outweigh risk, such as in this young patient with node-positive breast cancer. Tamoxifen and trastuzumab are contraindicated in pregnancy.
4. Answer: B. The most common type of lymphoma seen in pregnant women is diffuse large B-cell lymphoma, which is also the most common lymphoma seen in the general population. The most common type of leukemia seen in pregnant women is chronic myeloid leukemia.
5. Answer: B. The use of imatinib and other BCR-ABL tyrosine kinase inhibitors is contraindicated during pregnancy, because it is associated with exencephaly, encephalocele, exomphalos, and skull bone abnormalities with fetal loss.
