When Cancer Spreads to the Lungs

Medically Reviewed by Melinda Ratini, MS, DO on August 24, 2022
4 min read

Sometimes cancer that starts in one part of your body, known as the primary site, spreads to other parts. That’s because cancer cells can travel, or metastasize, via your bloodstream or lymph system.

When those primary cancer cells travel to your lungs, it’s called metastatic or secondary lung cancer. It’s a life-threatening condition. And it’s found in about a third of the people who die from cancer.

Cancer can spread to any part of your lungs. And you might have one tumor in one lung or many tumors in both lungs. But most of the time they’re on the edges of your lungs or in the lower lobes.

Primary tumors can spread from almost anywhere in the body to your lungs. But some types of cancer are more likely to grow in your lungs. These include:

At first, you may not know the cancer has spread to your lungs. That’s because some people have no symptoms. If you do have symptoms, they may include:

You can also have more general symptoms, including fatigue, loss of appetite, and weight loss.

Of course, these are all common signs of many other medical conditions, from mild to serious. That’s why it’s important to see your doctor if you have any of these symptoms.

After the doctor asks about your health history and gives you a physical exam, they may do one or more clinical tests to diagnose secondary lung cancer. These typically include:

These tools help the doctor find the source of cancerous cells. They’ll look like cancer cells from the primary site, not like lung cancer cells.

When cancer has spread to your lungs, treatment can help control and slow the growth of cancerous cells. It also helps you manage your symptoms so you have a better quality of life.

These things control how treatable lung cancer is:

  • The size, number, and location of your primary tumors
  • Where the cancer started
  • How widespread the cancer Is
  • How healthy your lungs are overall
  • Your symptoms
  • Cancer treatments you’ve already had
  • How you want to treat your cancer

Cancer that has spread to your lungs is also probably in your bloodstream. It could be in places that don’t show up on imaging scans. That’s why doctors mostly use chemotherapy to treat metastatic lung cancer. It destroys cancerous cells everywhere in your body.

Surgery is less common. Doctors use it if the tumors are only in a small part of the lung (they’ll call this isolated or limited metastasis). It can also help when the primary cancer is colorectal cancer, bone cancer, or soft tissue sarcoma.

Other treatment options include:

  • Hormonal therapy. This slows the growth of certain types of cancer cells and eases your symptoms.
  • Targeted therapy. It uses medications that attach to proteins on cancer cells to stop or slow their growth.
  • Immunotherapy. This uses your body’s immune system to destroy cancer cells.
  • Ablation therapy. It destroys cancer cells or tumors with lasers or electrical currents.
  • Radiation. High energy X-rays are used to destroy tumors.
  • Thoracentesis. This uses a needle to remove fluid in the space between your lungs and chest wall.
  • Oxygen therapy. It helps you breathe.
  • Stents. They open up narrowed airways.

Lung cancer is the leading cause of cancer deaths in the world. There’s no way to prevent metastatic lung cancer, but there are ways to treat it. And there’s reason to be hopeful: Doctors are working on new treatments every day. Immunotherapy, which boosts your body’s own cancer-fighting powers, has shown promise in recent years.

Your outlook for living with metastatic lung cancer depends in part on where the cancer started. It’s rare, but people with sarcoma, renal cell carcinoma, bladder cancer, colon cancer, or melanoma can sometimes be cured with surgery. And chemotherapy may cure some people with cancer that started in the testicles or lymph nodes.

Most people with this type of cancer can expect to live about 5 years. But that doesn't take into account newer treatments, like immunotherapy, which boosts your body’s own cancer-fighting powers. And it also doesn’t reflect that everyone is different. How well you respond to treatment depends on what treatment you and your doctor chose, your overall health when you were diagnosed, how soon you were diagnosed, and how far the cancer has spread.

Living with lung cancer takes a toll on your mental health, not just your physical health. So it’s key to take steps to manage your stress and anxiety.

Joining a cancer support group or talking privately with a therapist are both good ways to deal with your feelings. Ask your doctor to suggest options that may be right for you.