Chest X-Ray's Role in Breast Cancer Staging

Nurse examining chest x-rays in hospital
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In the past, chest x-rays were almost always ordered as part of the breast cancer staging process, but this is changing, and a chest x-ray may or may not be one of the tests you receive. While chest x-rays have a low yield of detecting lung metastases (when they are done to see if your cancer has spread to your lungs), there are many other reasons why a chest x-ray may be recommended. Let's look at what we currently know about chest x-rays and breast cancer staging as well as indications for chest x-rays during treatment.

Chest X-Rays and Breast Cancer Staging

After you are diagnosed with breast cancer and before you begin treatment, your doctor will determine the stage of your cancer. In actuality, you may not know the stage until after you have surgery, a sentinel node biopsy, and potentially a PET scan or other tests.

Chest x-rays are no longer recommended as part of staging according to the guidelines of the National Comprehensive Cancer Network. A 2015 study looking at chest x-rays done as part of staging found that this test did not improve the detection of occult metastases but did increase costs. In addition, chest x-rays in people with early-stage breast cancer have a high incidence of false positives, which can, in turn, increase emotional distress.

As an added concern, some studies (though not all), have found that chest x-rays may increase breast cancer risk in young women who carry BRCA gene mutations. While a 2013 study did not confirm earlier findings, the potential of an increased risk along with the a lack of benefit (not to speak of cost concerns) are topics that people may want to discuss with their doctors.

That said, many cancer centers still order chest x-rays as part of the staging process for breast cancer.

Reasons for a Chest X-Ray During Breast Cancer Treatment

There are several reasons other than staging why your oncologist may order a chest x-ray. Some of these include:

  • To evaluate any breathing problems, such as a cough or shortness of breath, that you have either prior to or during treatment
  • To take a look at your heart and lungs before you have surgery (and a general anesthetic) or chemotherapy
  • To look for evidence of pneumonia if you develop a fever while on chemotherapy. A low white blood count (neutropenia) can increase your risk.
  • To look for evidence of radiation pneumonitis (inflammation of the lungs) while you are receiving or after you have had radiation therapy. Some of the chemotherapy drugs used for breast cancer can also cause inflammation of the lungs.
  • As part of a clinical trial. A chest x-ray may be one of the criteria for participating in the clinical trial.
  • To look for evidence of lung metastases (spread of breast cancer to the lungs) if you develop any symptoms that are suggestive of this

Metastatic Breast Cancer and Chest X-Rays

The lungs are a common site of breast cancer metastases in people with metastatic breast cancer, and there is often confusion when this occurs. Cancer which spreads to the lungs from the breast (even if the breast tumor was removed years earlier) is still breast cancer. If you took out the tumors in the lungs and looked at them under the microscope, you would see cancerous breast cells, not lung cells. When breast cancer spreads to the lungs it is referred to as breast cancer with lung metastases, not lung cancer. This is important because the best treatment options are those that treat breast cancer, not lung cancer.

When breast cancer spreads to the lungs, there may not be any symptoms at first. When symptoms occur they often include a dry cough, shortness of breath, or recurrent respiratory infections.

Roughly 4 percent of people have metastases (most common are bones, liver, lungs, and brain) at the time of diagnosis.

Limitations of Chest X-Rays in Looking for Cancer

If your doctor is concerned that you may have a tumor or metastases in your lungs, a better test is a chest CT scan (or PET scan). Chest x-rays are limited in their ability to detect small areas of cancer (either metastases or a primary lung tumor). In fact, screening chest x-rays are not recommended for people who smoke because they fail to pick up a cancer early enough to make any difference in survival.

Recent studies suggest this is even more important. When looking at spread of breast cancer to the lungs, researchers have found that abnormalities detected on a scan of the lung are just as likely to be a primary lung tumor as breast cancer metastases in people who have early stage breast cancer. Since we know that chest X-rays can miss up to 25 percent of these cancers, a chest X-ray alone could give false confidence that everything is alright, and it that sense, be more detrimental than not performing the test at all.

In those who have higher stages of breast cancer (for example, stage 2A and higher), a PET/CT is considered a more helpful test to look for evidence of metastatic disease.

Ask Questions and Expect Answers

It's not uncommon for someone with breast cancer to be told they need a chest x-ray, but unless we know why it's being done, our brains can fill in the answers. "Maybe she's worried my cancer is in my lungs!" It could simply be that your oncologist is following up on a cough with a recent cold you told her about. The best way to avoid misunderstandings and the consequent emotional turmoil in guessing is to ask a lot of questions about the tests recommended for you. Being your own advocate for your cancer care not only reduces anxiety but may even improve outcomes.

A Word From Verywell

In the past, guidelines for breast cancer staging recommended a screening chest x-ray to look for any evidence of metastases to the lungs. It's been found that the yield from these studies is very low, and this is no longer recommended. There are, however, many potential reasons why your doctor might recommend a chest x-ray during your treatment. With changes happening so rapidly in oncology, it's more important than ever to ask questions and be your own advocate in your care.

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