Blood cancers during pregnancy are rare, but rare does not mean simple. It means every decision feels like it was designed by a committee of chaos goblins. The doctor is not just treating a cancer. They are balancing the health of the pregnant patient, the timing of the pregnancy, the type of cancer, how fast it is moving, and which treatments might cross the placenta and cause trouble. In other words, this is not "follow the usual recipe and bake at 350."
The new paper by Dierickx and colleagues lays out expert guidance for diagnosing and treating several hematologic malignancies during pregnancy, including acute leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, myeloproliferative neoplasms, aplastic anemia, and multiple myeloma. It also tackles the hard stuff: chemotherapy, radiation, and immunotherapy, all in the setting where the phrase "acceptable risk" suddenly gets very personal. [1]
The placenta is not a magic force field
A lot of people hear "pregnancy" and assume cancer treatment must fully stop until delivery. Not necessarily. The key issue is timing.
The first trimester is the sketchiest stretch because that is when major fetal organs are forming. Many anticancer drugs are much riskier then. Later in pregnancy, some chemotherapy regimens can sometimes be used with better fetal safety than most people expect, especially when managed by teams that do this for real and not just in inspirational conference slides. Broad cancer-in-pregnancy reviews and recent clinical studies support that idea, while also making it clear that "some" does a lot of work in that sentence. [2-5]
Basically, the placenta is less a brick wall and more a very selective bouncer. Some things get through. Some do not. Some are fine later in pregnancy and a terrible idea earlier. Radiation is particularly tricky because dose and body location matter a lot. Immunotherapy is one of those areas where modern oncology gets exciting and pregnancy gets nervous, because the immune system and the pregnancy are already in a complicated relationship. The expert opinion paper exists precisely because newer cancer treatments are outpacing the pregnancy-specific data. [1,2]
What makes this paper worth your time
The interesting part is not that doctors need to be careful. We already knew that. The interesting part is that cancer care in pregnancy is slowly moving away from the old panic-button reflex of "delay everything" or "end the pregnancy first" and toward something more nuanced.
That shift matters because preterm delivery itself can cause long-term problems for babies, and several reviews now stress that avoiding unnecessary early delivery should be a major goal whenever the cancer situation allows it. [2,5] That sounds obvious, but medicine has a long history of doing obvious things only after several committees, three consensus statements, and one person with a laser pointer says, "Have we tried not making this worse?"
The paper also highlights something very human: pregnant patients with blood cancers do not fit neatly into one specialty’s box. Hematology needs obstetrics. Obstetrics needs neonatology. Radiology needs to know what is safe to image and when. Everyone needs to communicate like adults. Recent literature on cancer during pregnancy keeps hammering that same point, because fragmented care in this setting is a terrible plot twist. [2,4,5]
Why this could matter in the real world
If these recommendations hold up and get adopted widely, the payoff is huge. More patients could receive timely cancer treatment without automatically sacrificing the pregnancy. More babies could avoid avoidable prematurity. And more clinicians in non-mega-center hospitals might have a roadmap when a case like this walks through the door at 2:17 p.m. on a Thursday, right after someone reheats fish in the staff microwave.
There are still big gaps. Pregnancy-specific evidence is thin because pregnant patients are usually excluded from clinical trials. Many newer drugs have little human safety data. Different blood cancers behave very differently, so there is no one-size-fits-all cheat code. But this paper pushes the field toward a more practical truth: pregnancy does not erase cancer biology, and cancer treatment does not have to erase thoughtful obstetric care. [1-4]
That is not a tidy happy ending. It is better. It is medicine getting less blunt.
References
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Dierickx D, Heimovaara JH, Bellido M, et al. Expert Opinion on the Diagnosis and Treatment of Hematologic Malignancies During Pregnancy. Journal of Clinical Oncology. Published online April 24, 2026. doi:10.1200/JCO-25-02351
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Varella L, Partridge AH. Approaching cancer during pregnancy. Nature Reviews Cancer. 2024;24:159-160. doi:10.1038/s41568-023-00647-6
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Gangat N, Tefferi A. Myeloproliferative neoplasms and pregnancy: Overview and practice recommendations. American Journal of Hematology. 2021;96(3):354-366. doi:10.1002/ajh.26067
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Cairncross ZF, Cresswell K, Clifton-Hadley L, et al. CAnceR IN PreGnancy (CARING) - a retrospective study of cancer diagnosed during pregnancy in the United Kingdom. British Journal of Cancer. 2024. doi:10.1038/s41416-024-02605-x
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Schwab R, Anic K, Hasenburg A. Cancer and Pregnancy: A Comprehensive Review. Cancers (Basel). 2021;13(12):3048. doi:10.3390/cancers13123048 PMCID:PMC8234287
Disclaimer: The image accompanying this article is for illustrative purposes only and does not depict actual experimental results, data, or biological mechanisms.