When Lung Cancer Spreads to Lymph Nodes

Diagnosis, Staging, and Prognosis of Lymph Node Metastases

Lung cancer often spreads to the lymph nodes before spreading to other regions of the body. What lymph nodes are involved, and where these are in relation to the primary cancer, are important questions to ask when determining the stage of a cancer. Let's take a look at the different types of lymph nodes you may hear about on your pathology reports, how the spread of lung cancer to lymph nodes is diagnosed, and what it will mean in terms of your treatment and prognosis if lymph node metastases have occurred.

Before talking about lymph node metastases it's important to talk about a confusing issue when doctors talk about lymph node involvement. If you read a report of a scan or biopsy, you may see the phrase "metastatic to lymph nodes." Having a cancer that has spread to lymph nodes (metastasized to lymph nodes) does not mean that you have metastatic cancer. Even some early stage lung cancers (for example, some stage 2A lung cancers) have positive lymph nodes.

While not a sign that lung cancer is metastatic, the presence of cancer in lymph nodes tells doctors that the tumor "intends" to spread further, and usually more aggressive treatment will be required to reduce the risk of recurrence.

Lymph Node Metastases

Lung cancer can invade nearby tissues, but can also spread (metastasize) in three primary ways. It may spread through:

  • The lymphatic system
  • The bloodstream
  • The airways: It's also now thought that lung cancer, unlike some other cancers, may spread through the airways as well.

When lung cancer cells travel through the lymphatic system they are carried to lymph nodes where they can lodge and grow. Lung cancer often spreads first to lymph nodes near the tumor, known as regional lymph nodes, but may also spread to lymph nodes in distant regions. Some terms you may hear that describe lung cancer that has spread to lymph nodes near the tumor include “regional disease,” “local spread,” or “locally advanced disease.”

Which Lymph Nodes May Be Impacted

The lymph nodes that lung cancer spreads to first often depends upon the location of the tumor. If you read through any of your radiology reports, words describing lymph node involvement can be very confusing. A simplistic way to think about lung cancer that spreads to lymph nodes is to divide the nodes into three regions:

  • Intrapulmonary lymph nodes: This term refers to lymph nodes that lie within the lungs. These can either be peripheral lymph nodes—that is, the lymph nodes that are found in the outer regions of the lungs—or hilar lymph nodes, which are present in the region of the chest where the bronchi and major arteries and veins enter the lungs (the hilum).
  • Mediastinal lymph nodes: These are lymph nodes that are present in the area of the chest between the lungs (the mediastinum).
  • Extrathoracic lymph nodes: This term refers to lymph nodes found outside of the thorax (chest). These include supraclavicular lymph nodes, located in the area just above the collarbone; and scalene lymph nodes, which are in the neck, near the uppermost rib.

Another way that lymph nodes are classified is based on the side of the body where they are located:

  • Ipsilateral lymph nodes: This refers to lymph nodes on the same side of the body as the tumor.
  • Contralateral lymph nodes: Contralateral lymph nodes on the other side ("contra") of the chest from the tumor.

Symptoms

You may not have any symptoms specifically related to your cancer spreading to your lymph nodes. If you do have symptoms, these may include:

  • Swelling in your neck or in the area just above your collarbone.
  • Shortness of breath due to pressure from swollen lymph nodes in your chest.
  • Hoarseness due to pressure on nerves caused by swollen lymph nodes in or near your lungs.

Diagnosis

After a lung cancer is diagnosed, your physician will recommend tests to see if your tumor has spread to lymph nodes or to distant sites. Determining if, and what, lymph nodes your cancer has spread to is important for choosing the best possible treatment. Some tests that may be done include:

  • CT scan or MRI of your chest and abdomen
  • PET Scan: A PET scan is particularly helpful if you have non-small cell lung cancer. Unlike a CT or MRI that look for structural changes on imaging, a PET scan looks for functional changes. In this procedure, radioactive glucose is injected into a vein and then a scan is done to see the areas that light up (areas that are more metabolically active). This can be helpful in distinguishing between lymph nodes and lung tissue that is affected by scarring (can cause a mass but isn't actively growing) relative to areas of cancer that cause a mass but are also actively growing.
  • Endobronchial Ultrasound
  • Mediastinoscopy
  • Lymph node biopsy: If lymph nodes can be accessed by a procedure such as an endobronchial ultrasound or mediastinoscopy, your doctor may take a sample of the lymph node to test it for cancer cells

Determining whether or not a lung cancer has spread to mediastinal lymph nodes can be very important in choosing the best treatments. In the past, a mediastinoscopy was the procedure most often performed, but is an invasive procedure (a tube is inserted through the chest wall into the mediastinum in the operating room to visualize the lymph nodes). PET scans have now replaced the need to do mediastinoscopy in a number of lung cancers.

Staging

TNM staging of lung cancer is a method of staging that takes into account the size of your tumor, the presence of lymph nodes affected by the cancer, and any evidence of spread of your tumor to distant regions of your body. In TNM staging, the N stands for lymph node involvement:

  • N0: No spread of tumor to lymph nodes
  • Nx: It can't be determined if the cancer has spread to the lymph nodes or not
  • N1: The tumor has spread to nearby nodes on the same side of the body
  • N2: The tumor has spread to nodes further away but on the same side of the body
  • N3: Cancer cells have spread to lymph nodes on the other side of the chest from the tumor, or to lymph nodes near the collarbone or neck muscles

Treatment

The treatment for lung cancer that has spread to lymph nodes depends upon the stage of your cancer and your general health. If lung cancer has spread to only a few nearby lymph nodes, surgical treatment may be considered. If a tumor has spread to lymph nodes further away or to distant regions, treatment options usually include chemotherapyradiation therapy, targeted therapies, and/or immunotherapy.

Prognosis

The prognosis of a lung cancer that has spread to lymph nodes depends on several things, including which lymph nodes are affected, the type of lung cancer you have, the size of your tumor, whether your tumor has spread to other areas of your body, and your general health. Many clinical trials are looking for better ways to treat lung cancer and offer hope that the prognosis will improve in the future.

A Word From Verywell on Lymph Node Involvement with Lung Cancer

Determining which, if any lymph nodes in your body are positive for lung cancer cells is extremely important in selecting the best treatment options for your tumor. Identifying which lymph nodes and their relation to your primary tumor plays a large role in staging.

It can be somewhat difficult to know whether lymph nodes are affected by cancer, and it's not usually possible to do biopsies on all potential sites. For this reason, surgical exploration and imaging tests are relied on heavily. The presence of lymph nodes in the mediastinum (the region of the chest between the lungs) is very important both in separating out treatment options (for example, surgery vs other treatments) but has been notoriously difficult to study. In the past, a procedure called a mediastinoscopy was often performed so that surgeons could directly visualize these nodes. At the current time, PET scans combined with CT are often able to provide this information in a much less invasive way.

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Article Sources
  • Almeida, F. et al. Initial evaluation of the nonsmall cell lung cancer patient: diagnosis and staging. Current Opinions in Pulmonary Medicine. 2010. 16(4):307-14.
  • Riquet, M. et al. Prognostic classifications of lymph node involvement in lung cancer and current International Association for the Study of Lung Cancer descriptive classification in zones. Interactive Cardiovascular and Thoracic Surgery. 2010. 11:260-264.
  • Xia, Y., Zhang, B., Zhang, J., Li, W., Wang, K., and H. Shen. Evaluation of lymph node metastasis in lung cancer: who is the chief justice?. Journal of Thoracic Disease. 2015. 7(Suppl 4):S231-7.