Non-small cell lung cancer (NSCLC) makes up about 80% to 85% of lung cancers. It’s one of the two main categories of lung cancer along with small cell lung cancer (SCLC).

The survival rate for people with lung cancer is highest when it’s caught in the early stages, but it’s estimated that about 40% of lung cancers have spread to distant organs at the time of diagnosis. The spread of cancer to distant body parts is known as metastasis.

NSCLC can spread to almost any part of your body, but it most commonly spreads to bone. Studies have found lung cancer to be one of the most common causes of bone metastases. Cancer that has spread to bone often has a poor outlook and generally isn’t considered curable.

In this article, we take a closer look at bone metastasis in NSCLC, including symptoms and how it affects treatment and outlook.

Bone metastasis is the spread of cancer to bone tissue from another organ. Metastatic NSCLC is also referred to as stage 4 NSCLC.

It’s estimated that about 20% to 30% of people with NSCLC have bone metastases at the time of diagnosis and that an additional 35% to 40% of people develop bone metastases later.

Cancer can metastasize when tumor cells enter your lymph system or blood vessels. Once cancer cells enter these systems, they can spread to almost any part of your body. For people with NSCLC, bone is one of the most common areas of metastasis. Other common areas are:

  • the other lung
  • brain
  • liver
  • adrenal glands

In a 2017 study, researchers found adenocarcinoma was the most common type of NSCLC to metastasize. Adenocarcinoma makes up about 40% of NSCLCs.

The researchers also found that the ribs were the most common site of bone metastasis followed by the thorax (area between your neck and bottom of your rib cage) and lumbar spine.

People with bone metastasis share the same symptoms as other people with NSCLC along with specific symptoms depending on where in the skeleton cancer spreads.

General symptoms of NSCLC include:

Most people with bone metastases develop pain. According to the American Cancer Society (ACS), pain often initially comes and goes and tends to be worse at night. Pain might become more persistent as the cancer progresses.

Other signs and symptoms of bone metastases can include:

Doctors sometimes discover bone metastases with imaging before symptoms develop. Your doctor may order imaging to look for bone metastases if you have suggestive symptoms.

Many different types of imaging can potentially identify bone metastasis. Here are some of the types of imaging you may receive:

  • X-rays: X-rays can help doctors identify the size and shape of your tumors. However, they only detect about 40% to 50% of bone metastases and generally require a 30% to 75% decrease in bone density.
  • Magnetic resonance imaging (MRI): MRI is the imaging of choice when it’s suspected you might have spinal cord compression. It can detect about 95% of bone metastases.
  • Computed tomography (CT) scan: A CT scan can potentially identify cancer before there’s enough bone destruction for metastases to appear on X-rays.
  • Bone scans: Bone scans are especially useful for identifying osteoblastic metastases, which are areas where cancer cells cause too many bone cells to form. Bone scans can detect about 95% of metastases.
  • Fluorodeoxyglucose-positron emission tomography-CT scan (FDG-PET-CT): An FDG-PET-CT may be recommended if there’s a concern of bone metastases at the time of diagnosis. They can detect about 98% of metastases.

A definitive diagnosis can be made with a bone biopsy where a small section of bone tissue is extracted for lab analysis. A biopsy may not be performed if doctors have a high level of suspicion that the cancer has spread or if performing a biopsy would cause substantial risk.

Your doctor may also order a blood test to look for elevated calcium levels or other markers that suggest the cancer has spread.

NSCLC with bone metastasis isn’t generally considered curable. Treatment aims to:

  • reduce symptoms
  • maximize daily function
  • improve quality of life

Researchers are continuing to examine different treatments for metastatic NSCLC. Current treatment options include:

  • Painkillers: About 70% of people with bone metastases need opioids for pain management.
  • Chemotherapy: The most common chemotherapy drug combination for stage 4 NSCLC is cisplatin or carboplatin with gemcitabine. Although any other drug combinations may be used to try to destroy cancer cells.
  • Targeted therapy: Targeted therapy modifies genes and proteins in cancer cells to stop them from dividing. Your doctor may recommend targeted therapy if you have certain gene mutations.
  • Surgery: Surgical removal of the primary lung tumor may help some people obtain longer survival. Surgery may also be used to treat metastases that have severely weakened a bone or are causing spinal cord compression.
  • Radiation therapy: Radiation therapy can potentially help shrink metastatic tumors. About half of people experience pain relief after 1 or 2 weeks.
  • Bisphosphonates and denosumab: The Food and Drug Administration (FDA) has approved bone-modifying agents, such as bisphosphonates and denosumab, for the management of bone metastases in all solid tumors to prevent bone loss.

NSCLC with bone metastasis is generally associated with a poor outlook, but the outlook is slowly improving over time.

People with bone metastasis frequently have severe pain, drastically reduced quality of life, and a reduced ability to perform daily tasks. The ACS lists the 5-year relative survival rate for people with NSCLC spread to distant organs as 8%.

Only about half of people with metastatic NSCLC live more than 14 to 17 months.

In a 2019 study, researchers found some evidence that younger people with bone metastases may have better survival than older people. They found people under 60 years lived an average of 11 months while people over 60 years lived an average of 8.8 months.

NSCLC can spread to distant organs if cancer cells reach your bloodstream or lymph system. Bone is the most common place for NSCLC to spread.

Metastatic NSCLC tends to have a poor prognosis, and treatment generally aims to maximize quality of life and minimize symptoms.

Receiving a cancer diagnosis can be difficult, but your doctor can help you develop the best treatment plan for your specific situation.

Survival rates are slowly improving over time as treatment improves. Your doctor may recommend taking part in a clinical trial that may give you access to treatment that’s more effective than current standard treatments.