Lung Cancer Treatment During Pregnancy: What You Need to Know

Pregnancy does not automatically mean that all cancer treatment must wait until after the baby is born.

Some treatments may be considered during pregnancy in carefully selected circumstances, while others are usually delayed or avoided. The type and stage of lung cancer, how urgently treatment is needed and the stage of pregnancy all need to be considered together.

Why Timing Matters When Treating Lung Cancer During Pregnancy

Pregnancy is divided into three trimesters, and the potential effects of cancer treatment are different at each stage.

The first trimester is particularly important because the baby's major organs are developing. Exposure to certain anti-cancer medicines during this period can increase the risk of miscarriage and congenital abnormalities, which significantly limits the treatments that can safely be considered.

After the first trimester, some treatment options may become possible. However, this does not mean that every cancer treatment is suitable later in pregnancy. Each medicine and procedure has to be assessed individually.

For someone diagnosed during pregnancy, a lung cancer treatment plan needs to consider the cancer subtype and stage alongside gestational age and the potential risks of either proceeding with or delaying treatment.

How Is Lung Cancer Assessed During Pregnancy?

Accurate diagnosis and staging remain essential because doctors need to know exactly what they are treating before recommending a plan.

A biopsy may be required to establish whether the cancer is non-small cell lung cancer (NSCLC) or small cell lung cancer (SCLC). Molecular and biomarker testing can also be particularly important in NSCLC because the results may identify alterations such as EGFR, ALK or ROS1 that would ordinarily influence treatment.

Imaging may also be required to establish the extent of the disease. The choice of investigation is made carefully during pregnancy, taking into account whether it involves ionising radiation, whether contrast is needed and how urgently the information is required.

Pregnancy should not prevent appropriate investigation of suspected cancer. Instead, the diagnostic approach is adapted so that the information needed for treatment planning can be obtained while minimising unnecessary risk.

Can Lung Cancer Surgery Be Performed During Pregnancy?

Surgery may be considered during pregnancy when the cancer is localised, and an operation offers an appropriate route to treatment. In early-stage lung cancer, surgery can form an important part of treatment for patients whose cancer is suitable for removal. During pregnancy, however, the timing and safety of an operation require additional assessment.

Surgery can often be performed during pregnancy when necessary, although the timing depends on the type and urgency of the operation, gestational age and the health of both mother and baby.

Lung cancer surgery is a major procedure, so the decision requires input from thoracic surgeons, anaesthetists, oncologists and obstetric specialists.

The important point is that pregnancy does not automatically rule out surgery. The risks of operating need to be weighed against the potential consequences of allowing the cancer to progress while waiting until after delivery.

Can Chemotherapy Be Given During Pregnancy?

Chemotherapy presents different considerations depending on the stage of pregnancy.

It is generally avoided during the first trimester because exposure during early fetal development can increase the risk of miscarriage and congenital abnormalities.

After the first trimester, certain chemotherapy medicines have been used during pregnancy. However, treatment must be selected carefully by a consultant oncologist, and the evidence available for individual chemotherapy regimens varies.

Chemotherapy is usually planned to stop several weeks before the expected delivery date, allowing time for blood counts to recover and reducing the risk of complications around labour and birth.

For lung cancer specifically, the decision is particularly individual because the chemotherapy normally recommended depends on whether the diagnosis is NSCLC or SCLC, its stage and the overall treatment goal.

What About Radiotherapy During Pregnancy?

Radiotherapy is generally avoided during pregnancy because ionising radiation can potentially harm a developing baby. The level of risk depends on factors including the radiation dose, the part of the body being treated and the stage of pregnancy.

For lung cancer, radiotherapy would usually be postponed until after delivery where this can be done safely. If urgent radiotherapy were being considered during pregnancy, detailed specialist assessment of fetal radiation exposure would be required.

There can be exceptional situations in cancer care where radiotherapy is considered during pregnancy because treatment is urgently required. These are highly specialised decisions that need careful discussion within a multidisciplinary team.

Modern techniques such as stereotactic radiotherapy can deliver radiation very precisely, but precision alone does not make it suitable during pregnancy.

Are Immunotherapy and Targeted Therapy Safe During Pregnancy?

Modern lung cancer treatment increasingly involves immunotherapy and targeted medicines, but pregnancy substantially changes how these treatments are considered.

Outside pregnancy, systemic therapy for lung cancer may include chemotherapy, immunotherapy and targeted medicines. During pregnancy, however, each of these treatments has to be considered separately because their safety profiles and the evidence available are very different.

Immunotherapy works by helping the immune system recognise and attack cancer cells. Because normal immune regulation is important in maintaining pregnancy, checkpoint inhibitors raise potential concerns for the developing baby, and safety data in pregnant patients remain limited.

For these reasons, immunotherapy is generally avoided during pregnancy unless an exceptional individual situation leads the specialist team to consider otherwise.

Targeted therapies require similar caution. Although molecular testing may identify an actionable alteration such as EGFR or ALK, identifying the mutation does not automatically mean that the corresponding drug can safely be used during pregnancy.

Evidence varies considerably between medicines, and many targeted therapies are not recommended during pregnancy because fetal safety has not been established or because preclinical data suggest potential harm.

Molecular testing can still be valuable because the results may influence treatment after delivery or contribute to decisions about the timing and sequencing of therapy.

Does Treatment Ever Need to Wait Until After Delivery?

Sometimes it does, but delaying treatment is not automatically the safest option.

If the cancer appears relatively slow-growing, the pregnancy is already advanced, and the oncology team believes a short delay is unlikely to compromise cancer control, treatment may potentially be postponed until after delivery.

In other situations, waiting could allow the cancer to progress, and treatment may need to begin during pregnancy.

In some circumstances, the timing of delivery may form part of the treatment discussion, particularly when cancer treatment cannot safely be given during pregnancy. Any decision to deliver early needs to balance the urgency of cancer treatment against the risks of prematurity.

This is why there is no universal answer to whether treatment should begin immediately, be modified or wait until after birth. The balance is different for every patient.

Who Should Be Involved in Treatment Decisions?

Lung cancer during pregnancy requires close collaboration between several specialists.

The multidisciplinary team may include:

• A clinical or medical oncologist
• A thoracic surgeon
• An obstetrician specialising in high-risk pregnancy
• A fetal medicine specialist
• A radiologist
• An anaesthetist
• A neonatologist where early delivery is being considered

The oncology team considers the urgency and likely effectiveness of cancer treatment, while the obstetric and fetal medicine teams assess how different options could affect the pregnancy.

For particularly complex cases, seeking a second opinion can provide another specialist assessment of the diagnosis, treatment sequence and whether there are reasonable alternatives to the plan already proposed.

Does Pregnancy Affect the Chances of Successful Lung Cancer Treatment?

Because lung cancer during pregnancy is rare, there is limited evidence allowing doctors to predict outcomes specifically for pregnant patients.

Prognosis is therefore assessed mainly using the same factors that matter outside pregnancy, including the type of lung cancer, its stage, molecular characteristics and response to treatment.

Pregnancy itself does not provide a simple prediction of how successful treatment will be. The difficulty is that pregnancy may restrict or alter the timing of treatments that would ordinarily be considered, which makes early specialist planning particularly important.

Modern lung cancer treatment success can mean different things depending on the diagnosis. For early-stage disease, treatment may be given with curative intent. With advanced cancer, success may instead mean controlling disease for longer, relieving symptoms and maintaining quality of life.

The aim during pregnancy is to preserve effective cancer treatment wherever possible while minimising avoidable risks to the developing baby.

About Dr James Wilson

Treating lung cancer during pregnancy requires a highly individual approach. The safest treatment plan depends on the biology and stage of the cancer, the stage of pregnancy and the potential consequences of either proceeding with or delaying treatment.

Dr James Wilson is a consultant clinical oncologist in full-time private practice in London, specialising in lung cancer and advanced radiotherapy. His work includes radiotherapy, chemotherapy, immunotherapy, targeted therapies and other systemic cancer treatments. He helps patients understand complex treatment recommendations and make informed decisions about their care.