By Chandley Silin, RN, FNP-BC, AOCNP®
A 33-year-old woman presents to the emergency department with fever, weight loss, and dyspnea. She is five months pregnant. A computed tomography (CT) chest scan without contrast shows a large mediastinal mass. Biopsy demonstrates Hodgkin lymphoma (HL), but magnetic resonance imaging (MRI) of her abdomen and pelvis without contrast is negative for lymphadenopathy. Her echocardiogram and pulmonary function testing are normal.
She is started on doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) at 31 weeks pregnant and begins seeing a high-risk obstetrics physician. She delivers a healthy baby at 37 weeks after two ABVD cycles but was advised not to breastfeed until two months after her cancer treatment ends. Positron-emission tomography (PET)/CT after delivery demonstrates complete remission, and she completes four additional ABVD cycles. End-of-treatment PET/CT demonstrates a continued remission.
HL in Pregnancy
HL is a rare lymphoma subtype, accounting for 10% of lymphomas, but it is the most common hematologic malignancy diagnosed during pregnancy, likely because of the increased incidence of HL during early adulthood.
Any cancer diagnosis in pregnancy carries both emotional weight and clinical implications. The embryo is most vulnerable during organogenesis in weeks two through eight. Most chemotherapy drugs are small enough to cross the placenta; therefore, to prevent birth defects or miscarriage, treatment is delayed until at least the second trimester.
Because of limited safety data for PET imaging in pregnancy and the high amount of radiation with CT, MRI is preferred for staging. Chest X-rays are done with abdominal shielding to reduce radiation exposure. Bone marrow biopsies are not routinely conducted for staging but can be safely performed.
Treating HL During Pregnancy
The most-used treatment regimen in HL is ABVD. After the first trimester, ABVD is considered safe. No case reports show fetal pulmonary damage from bleomycin or neurotoxicity from vinblastine, and a review by Evens et al. did not demonstrate cardiac toxicity secondary to in utero doxorubicin exposure.
Brentuximab (BV) was recently approved for advanced stage and relapsed HL. It is classified as pregnancy category D because of adverse reproductive effects in animal studies. Additionally, when combined with doxorubicin, vinblastine, and dacarbazine (AVD), BV is myelosuppressive and requires the use of growth factors, which have limited safety data in pregnancy. ABVD is therefore preferred over BV-AVD.
Radiotherapy after chemotherapy is often recommended. Although treating the neck and axilla pose a low risk of fetal radiation exposure, radiating fields closer to the diaphragm may increase the risk of congenital malformations in the first trimester and childhood cancer in the second and third.
Most supportive medications are safe, but lorazepam and prochlorperazine are classified as category D and C, respectively, and thus avoided. Dexamethasone is designated as category C but may be safely administered in reduced doses after the first trimester.
Special Patient Considerations
Breastfeeding during chemotherapy is typically contraindicated because doxorubicin is excreted in high levels into breast milk and vinblastine has a long half-life. Data on the safety of bleomycin and dacarbazine are limited, but the risks posed by the other drugs in the ABVD regimen outweigh the benefits of breastfeeding during treatment.
Outcomes for pregnant patients treated for HL mirror those of nonpregnant patients; the goal of treatment is curative. In a review of 40 patients undergoing antenatal chemotherapy, Evens et al. found three-year progression-free and overall survival rates of 85% and 97%, respectively.