Consensus guidelines for the perinatal management of hematologic malignancies detected during pregnancy have been issued by a panel of international experts.
The guidelines, published online in the Journal of Clinical Oncology, aim to ensure that timely treatment of the cancers is not delayed in pregnant women (doi: 10.1200/JCO.2015.62.4445).
While rare, hematologic malignancies in pregnancy introduce clinical, social, ethical, and moral dilemmas. Evidence-based data are scarce, according to the researchers, who note the International Network on Cancer, Infertility and Pregnancy registers all cancers occurring during gestation.
“Patient accrual is ongoing and essential, because registration of new cases and long-term follow-up will improve clinical knowledge and increase the level of evidence,” Dr. Michael Lishner of Tel Aviv University and Meir Medical Center, Kfar Saba, Israel, and his fellow panelists wrote.
Hodgkin lymphoma
The researchers note that Hodgkin lymphoma is the most common hematologic cancer in pregnancy, and the prognosis for these patients is excellent. When diagnosed during the first trimester, a regimen based on vinblastine monotherapy has been used. ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) therapy can be used postpartum and has been used in cases of progression during pregnancy, the panelists wrote.
“The limited data available suggest that ABVD may be administered safely and effectively during the latter phases of pregnancy,” the panel wrote. “Although it may be associated with prematurity and lower birth weights, studies have not reported significant disadvantages.”
Non-Hodgkin lymphoma
The second most common cancer in pregnancy is non-Hodgkin lymphoma. In the case of indolent disease, watchful waiting is possible, with the intent to treat with monoclonal antibodies – with or without chemotherapy – if symptoms or evidence of disease progression are noted. Steroids can be administered during the first trimester as a bridge to the second trimester, when chemotherapy can be used with relatively greater safety, the panelists noted.
Aggressive lymphomas diagnosed before 20 weeks’ gestation warrant pregnancy termination and treatment, they recommend. When diagnosed after 20 weeks, therapy should be comparable to that given a nonpregnant woman, including monoclonal antibodies (R-CHOP).
Chronic myeloid leukemia
Chronic myeloid leukemia occurs in approximately 1 in 100,000 pregnancies and is typically diagnosed during routine blood testing in an asymptomatic patient. As a result, treatment may not be needed until the patient’s white count or platelet count have risen to levels associated with the onset of symptoms. An approximate guideline is a white cell count greater than 100 X 109/L and a platelet count greater than 500 X 109/L.
Therapeutic approaches in pregnancy include interferon-a (INF-a), which does not inhibit DNA synthesis or readily cross the placenta, and leukapheresis, which is frequently required two to three times per week during the first and second trimesters. Counts tend to drop during the third trimester, allowing less frequent intervention.
Consideration should be given to adding aspirin or low-molecular-weight heparin (LMWH) when the platelet count exceeds 1,000 X 109/L.
Myeloproliferative neoplasms
The most common myeloproliferative neoplasm seen in women of childbearing age is essential thrombocytosis.
“A large meta-analysis of pregnant women with essential thrombocytosis reported a live birth rate of 50%-70%, first trimester loss in 25%-40%, late pregnancy loss in 10%, placental abruption in 3.6%, and intrauterine growth restriction in 4.5%. Maternal morbidity is rare, but stroke has been reported,” according to the panelists.
Limited literature suggests similar outcomes for pregnant women with polycythemia vera and primary myelofibrosis.
In low-risk pregnancies, aspirin (75 mg/day) should be offered unless clearly contraindicated. For women with polycythemia vera, venesection may be continued when tolerated to maintain the hematocrit within the gestation-appropriate range.
Fetal ultrasound scans should be performed at 20, 26, and 34 weeks of gestation and uterine artery Doppler should be performed at 20 weeks’ gestation. If the mean pulsatility index exceeds 1.4, the pregnancy may be considered high risk, and treatment and monitoring should be increased.
In high-risk pregnancies, additional treatment includes cytoreductive therapy with or without LMWH. If cytoreductive therapy is required, INF-a should be titrated to maintain a platelet count of less than 400 X 109/L and hematocrit within appropriate range.
Local protocols regarding interruption of LMWH should be adhered to during labor, and dehydration should be avoided. Platelet count and hematocrit may increase postpartum, requiring cytoreductive therapy. Thromboprophylaxis should be considered at 6 weeks’ postpartum because of the increased risk of thrombosis, the guidelines note.
Acute leukemia
“The remarkable anemia, thrombocytopenia, and neutropenia that characterize acute myeloid and lymphoblastic leukemia” require prompt treatment. Leukapheresis in the presence of clinically significant evidence of leukostasis can be considered, regardless of gestational stage. When patients are diagnosed with acute myeloid leukemia during the first trimester, pregnancy termination followed by conventional induction therapy (cytarabine/anthracycline) is recommended.