Is Lung Cancer in a Pregnant Woman Increasing?

What do You Need to Know About Lung Cancer During Pregnancy?

pregnant woman holding her hands o her chest
Lung cancer during pregnancy is not common and requires special management. istockphoto.com

How often do pregnant women develop lung cancer? Can people receive treatment for lung cancer while pregnant? Does the pregnancy need to be terminated? Since it appears that lung cancer in pregnant women is increasing, these are important questions. Remember that anyone with lungs can get lung cancer.

Lung Cancer in Pregnant Women

Many people are surprised to hear that pregnant women can develop lung cancer.

Most people associate lung cancer with those who are older and have smoked. Yet that's not always the case.

Lung cancer can occur in young adults and unlike the recent decreases in lung cancer in older people, lung cancer in younger people is increasing. In fact, for one group of people the incidence of lung cancer has increased the most: young, never-smoking women.

Yet while lung cancer may occur during pregnancy, it is not very common. We aren't sure of the actual incidence, but as of 2016, there were less than 70 cases of lung cancer in pregnant women which had been written up in the medical literature.

Is Lung Cancer Different in Pregnant Women?

There haven't been enough pregnant women with lung cancer to do in depth studies of these cancers, but we know that lung cancer in young adults is often different from lung cancer in older adults, that lung cancer in women may be different from lung cancer in men, and that lung cancer in non-smokers often differs from that in non-smokers.

Let's take a look at some of these differences.

Types of Lung Cancer Found in Pregnant Women

It's thought that lung adenocarcinoma, a type of non-small cell lung cancer, is responsible for around 85 percent of lung cancers found in pregnant women. This is the type of lung cancer which is found most often in young people and never smokers with the disease.

 

Why May it Be Hard to Diagnose Lung Cancer in Pregnant Women?

An obvious reason why diagnosing lung cancer in pregnant women can be difficult is that we usually try to avoid radiation exposure, such as lung CT scans or chest x-rays, during pregnancy. Another reason, however, has to do with the most common type of lung cancer found in pregnant women noted above.

There are two major categories of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). with 80 percent of lung cancers being NSCLC's. Non-small cell lung cancers are again broken down into lung adenocarcinomas (around 50 percent of NSCLC's) squamous cell carcinomas of the lung (30 percent of NSCLC's) and large cell lung cancer.

Small cell lung cancers and squamous cell lung cancers tend to occur near the large airways. These cancers tend to cause symptoms early on such as a cough, recurrent infections due to airway obstruction, or coughing up blood. In contrast, lung adenocarcinomas tend to grow in the periphery of the lungs. These cancers may grow quite large before they cause symptoms. Because of their location, they often cause slowly progressive shortness of breath, often first occurring only with exertion.

They may also cause fatigue. Since some degree of shortness of breath and fatigue is so common with pregnancy, many women first dismiss their lung cancer symptoms as being related to pregnancy, especially if they have never smoked.

Gene Mutations in Pregnant Women with Lung Cancer

Among young adults, non-smokers, and women with lung cancer, there is a greater incidence of "actionable gene mutations." In other words, tumors found in young people are more likely to have genetic changes for which the newer targeted therapies may be effective. For this reason it is extremely important for women who are diagnosed during pregnancy (as well as all young adults who are diagnosed with the disease) to have molecular profiling (gene testing) done on their tumors.

Some of these changes may include EGFR mutations, ALK rearrangements, ROS1 rearrangements, and more.

Diagnosing Lung Cancer in Pregnant Women

How can lung cancer be diagnosed and staged in a way which minimizes radiation exposure to the baby? There are options for testing for lung cancer in pregnant women. Tests such as MRI do not use radiation and are considered relatively safe in pregnancy. X-ray studies such as CT scans may be done when necessary if the baby is shielded from exposure.

Why is Lung Cancer in Pregnant Women Increasing

It's thought that the main reason why lung cancer in pregnant women is increasing is because lung cancer is increasing in young people worldwide. At the same time, the age at first pregnancy is increasing in developed countries. It appears that the cause goes beyond exposure to secondhand smoke, but the precise reasons have eluded us at this time. We do know that there is a relationship between estrogen and lung cancer but aren't certain whether this may play a role but aren't certain whether this may play a role

Facing Lung Cancer as a Pregnant Woman

A diagnosis of lung cancer during pregnancy may seem to come out of left field. You are waiting to hear the words "it's a boy" or "it's a girl," not  "you have lung cancer."

If you've been diagnosed with lung cancer during pregnancy, there are a few things you should know. People have received treatment during pregnancy and gone on to deliver healthy babies. It may be surprising, but treatments such as some types of chemotherapy are relatively safe for the baby during the latter part of pregnancy (not during first trimester.)

Managing Lung Cancer and Pregnancy at the Same Time

Being diagnosed with lung cancer during pregnancy is a little like walking a tightrope, but that tightrope walk can go much better if you have specialists helping you on both sides. It's important to find an oncologist who is comfortable treating pregnant women with lung cancer. You may need to get a second opinion (or a 3rd or a 4th.) At the same time, having an obstetrician who specializes in high-risk pregnancies is important. This physician can help you weigh the risks of prematurity with an early delivery with the risks of continuing the pregnancy and exposing the baby to the treatments you need.

During second and third trimester, chemotherapy is not associated with a teratogenic effect - meaning that chemotherapy is unlikely to cause birth defects. There is a risk of babies having a low birth weight as well as a small risk of intrauterine growth retardation. A 2010 study found that metastases to the baby from the tumor occurred 26 percent of the time. Due to this risk, your obstetrician may consider delivering your baby well before your official due date.

Fertility after Lung Cancer Treatment

If you develop lung cancer during pregnancy you may wonder about future pregnancies. It's true that some chemotherapy drugs can cause infertility, and thus these are questions you want to ask right away if you are hoping to have another child. There are options, such as freezing embryos before starting treatment, that can leave the door open if you would wish to become pregnant in the future. At that time you will face the decision about whether you are healthy enough to carry a baby or if you should consider a surrogate. 

Bottom Line on Pregnancy During Lung Cancer Treatment

Lung cancer during pregnancy is becoming more common. Though there are certainly many risks, many people have gone on to receive treatment and deliver healthy babies. Treatment of lung cancer during pregnancy depends on how far along you are (the gestational age of the baby.) and many other factors such as the type and stage of your cancer, molecular profiling, and social support.

Sources:

Azim, H., Peccatori, F., and N. Pavlidis. Lung Cancer in the Pregnant Woman: To Treat or Not to Treat, That is the Question. Lung Cancer. 2010. 67(3):251-6.

Boussios, S., Han, S., Fruscio, R. et al. Lung Cancer in Pregnancy: Report of Nine Cases from an International Collaborative Study. Lung Cancer. 2013. 82(3):499-505.

Garrido, M., Clavero, J., Huete, A., Sanchez, C., Solar, A., Alvarez, M., and E. Orellana. Prolonged Survival of a Woman with Lung Cancer Diagnosed and Treated with Chemotherapy During Pregnancy. Review of Cases Reported. Lung Cancer. 2008. 60(2):285-90.

Matrou, S., Petrakis, D., Fotopoulos, G. et al. Lung Cancer During Pregnancy: A Narrative Review. Journal of Advanced Research. 2016. 7(4):571-574.

Sariman, N., Levent, E., Yener, N., Orki, A., and A. Saygi. Lung Cancer and Pregnancy. 2013. 79(3):321-3.

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