Lung cancer in pregnancy is rare, but it is becoming more common, especially in younger women who have never smoked. A new study has looked at what happens when women take targeted treatments for lung cancer while pregnant. In most cases the pregnancy continued and the baby was born, and the treatments still worked well for the mothers. But many babies were born early, and the researchers say there is not yet enough evidence to call any of these treatments safe in pregnancy.
Why lung cancer in pregnancy is becoming more common
Lung cancer is being diagnosed more often in people under 50, particularly in young women who have never smoked. Many of these cancers are driven by a change in a gene such as ALK, EGFR or ROS1, and can be treated with targeted tablets called tyrosine kinase inhibitors (TKIs).
Because these treatments can keep lung cancer under control for years, more women of childbearing age are living well on long-term treatment. Some are diagnosed during pregnancy, and some become pregnant while on treatment.
Pregnant women are usually left out of clinical trials, so most of what doctors know comes from individual case reports, which tend to be published when outcomes are good.
What the researchers did
The study was published in the journal Drugs on 22 October 2026 and is free to read. It was carried out by an international team of researchers from Switzerland, Italy, France and the US, led by Dr Roberta Noseda and Dr Martina Imbimbo. They combined two types of evidence:
Global safety reports: they looked at reports sent to VigiBase, the World Health Organization’s global database of suspected side effects, between 2006 and February 2026. They found 162 reports of pregnancy exposure to targeted treatments used for lung and other chest cancers.
Published cases: they reviewed every published case they could find of women taking these treatments during pregnancy for lung cancer. This came to 26 women and 27 pregnancies, all with stage 4 lung cancer driven by ALK (14 women), EGFR (10) or ROS1 (2). Around half had never smoked.
What happened to the pregnancies and babies
In the published cases:
In 26 of the 27 pregnancies, the baby was born. One pregnancy did not continue because the mother’s cancer had progressed.
14 of the 26 babies (54%) were born early, before 37 weeks.
A third of pregnancies had complications, such as the baby being smaller than expected or low levels of fluid around the baby.
Around 1 in 5 babies had complications after birth, mostly with breathing.
The global safety reports showed a similar pattern. Compared with other cancer drugs, targeted treatments were more often reported alongside premature labour, low birth weight, babies being smaller than expected, and breathing problems in newborns. This type of data can highlight possible concerns, but it cannot measure true risk or prove the drugs caused them.
How the mothers’ cancers responded to targeted treatment
The treatments worked well for the mothers. In 21 of the 26 women (81%), the cancer responded to treatment, and in four women there was no sign of cancer on scans.
What the study found about alectinib and ALK+ lung cancer
Alectinib, a targeted treatment for ALK+ lung cancer, was the most common drug in the published cases. Across 10 pregnancies where women took alectinib alone:
there were no pregnancy or delivery complications
one baby needed help with breathing for three days after birth
Alectinib was found in the placenta and in breast milk.
Results for other drugs were more mixed. Both pregnancies on lorlatinib and both on osimertinib had complications, although one of the women on osimertinib was also taking another treatment. Half of the women on erlotinib had complications, and there were none in the four women on gefitinib.
The researchers are clear that 10 pregnancies is not enough to say alectinib is safe in pregnancy.
How researchers are filling the gaps
Because pregnant women are left out of trials, researchers rely on safety reports and published cases. These can show patterns worth looking into, but they can’t give the full picture.
To build better evidence, an international registry called LUCINAE (Lung and Thoracic Cancers during Pregnancy) is now collecting information on pregnancies in people with lung cancer. This includes pregnancies during treatment, pregnancies within five years of diagnosis, and pregnancies where the father is on cancer treatment. A Global Consortium on Lung Cancer in Pregnancy was also set up in 2025 to bring this work together internationally.
What this means for women living with lung cancer
The researchers say targeted treatment during pregnancy can be considered in carefully selected cases. That decision should be made individually, with a team of specialists, after weighing up the benefit for the mother against the possible risk to the baby.
If you are living with lung cancer and are pregnant, or are thinking about pregnancy, talk to your oncology team before making any changes to your treatment.
Read the research: Noseda R, Salfi G, Bedussi F, et al. Small molecules prescribed on- and off-label for thoracic cancers during pregnancy: a combined VigiBase and systematic review analysis. Drugs. 2026. doi:10.1007/s40265-026-02405-y
