SAN DIEGO – Women diagnosed with lymphoma during pregnancy stand a good chance of carrying a healthy child to term even when they opt for treatment during the second or third trimester, according to a retrospective multicenter analysis.

Among 82 women diagnosed with either Hodgkin’s or non-Hodgkin’s lymphoma during pregnancy, 48 opted to start therapy during pregnancy rather than defer it until after delivery, investigators reported at the annual meeting of the American Society of Hematology.

All but one woman had a normal birth, the exception being a severe malformation: microcephaly in the fetus of a woman who had received four cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) for diffuse large B-cell lymphoma (DLBCL).

The timing of therapy did not appear to affect overall survival, with the 3-year progression-free survival (PFS) rate being 76% among women who underwent treatment during pregnancy, compared with 79% for those who deferred it, said Dr. Andrew M. Evens of the University of Massachusetts in Worcester.

Respective overall survival rates were 92% and 83%, he reported. For the six women who elected to terminate their pregnancies, the 3-year PFS rate and overall survival rate were each 100%.

Among 39 women with Hodgkin’s lymphoma (HL), the 3-year PFS rate was 90%, and overall survival was 95%. Among 33 patients with B-cell non-Hodgkin’s lymphomas (NHL), 73% were progression free at 3 years; the overall survival rate was 82%. For 10 women with NHL of T-cell histology, the respective figures were 50% and 90%.

"We conclude that standard chemotherapy – non-antimetabolite chemotherapy – and radiation in select cases, in particular localized disease likely above the diaphragm during the second and third trimester, were associated with expected maternal complications and fetal detriment," Dr. Evens said.

Women with low-risk disease, such as indolent NHL, or a diagnosis late in gestation may be able to defer therapy until after delivery, he added.

Cancers in Pregnancy Uncommon. Cancer diagnoses during pregnancy are uncommon, occurring in about 3,500 women annually in the United States. The estimated prevalence is 1 in 1,000 gestations. Hematologic malignancies, primarily lymphomas, account for about 20% of all cancers diagnosed in pregnancy, Dr. Evens said.

He and his colleagues at nine academic medical centers conducted a descriptive retrospective analysis looking at histology, disease characteristics, therapy received, and maternal and fetal complications among pregnant women diagnosed with lymphomas from 1998 through 2011.

Of the 82 women identified for whom follow-up data were available, 43 (52%) were diagnosed with NHL (83% B-cell and 17% T-cell histologies) and 39 (48%) with HL. The median time of diagnosis was at 24 weeks gestation (range 5-40 weeks).

Six patients (4 with NHL and 2 with HL) decided to terminate the pregnancies to have immediate chemotherapy. Five of these patients were diagnosed in the first trimester and required systemic therapy.

The remaining patient was diagnosed early in the second trimester with lymphoma involving the central nervous system and requiring high-dose methotrexate, an antimetabolite in FDA pregnancy category X (positive evidence of fetal harm from animal or human studies and/or clinical experience; contraindicated). Other antimetabolites are classified in category D (positive evidence of fetal risk, but the benefits may warrant use in pregnant women).