Lung Cancer Metastasis to the Brain

Brain metastasis is a common complication of advanced lung cancer. It occurs when cancer cells break away from the primary lung tumor and travel through the bloodstream or lymphatic system to reach the brain. Once there, the rogue cells can establish secondary tumors. Although distinct from primary brain cancer, which begins in the brain itself, metastatic brain tumors can similarly affect delicate brain tissues and cause significant neurological complications.

What are the symptoms of lung cancer metastasis to the brain?

The symptoms of lung cancer metastasis to the brain can vary based on the location, size and number of brain tumors. Possible signs include:

• Headaches – Often persistent and may worsen over time
• Seizures – New-onset seizures or increased seizure activity in individuals with a prior history
• Cognitive changes – Memory loss, mental confusion or difficulty concentrating
• Numbness and muscle weakness – Typically on one side of the body
• Difficulty with balance or coordination – Can increase the risk of falls
• Vision problems – Blurred vision or loss of peripheral vision
• Speech difficulties – Slurred speech or trouble finding words
• Nausea or vomiting – Especially in the morning or when accompanied by headaches

Brain metastasis symptoms can appear suddenly or develop gradually. In a patient with lung cancer, any new or worsening neurological symptoms should prompt an immediate medical evaluation.

How is lung cancer metastasis to the brain diagnosed?

Usually, brain metastasis is diagnosed through a combination of clinical assessment and imaging studies. If a patient with lung cancer begins to experience neurological symptoms, such as headaches, seizures or cognitive changes, the physician may suggest:

• Magnetic resonance imaging (MRI) – The most sensitive imaging test for detecting brain metastasis, MRI can provide detailed visuals of the brain structures, helping the physician identify even small or subtle lesions.
• Computed tomography (CT) – A CT scan may be used if rapid imaging is needed or MRI is unavailable. Computed tomography can detect large tumors and swelling in the brain.
• Neurological examination – To help localize possible brain involvement, the physician may perform a series of tests to assess the patient’s coordination, reflexes, vision, strength and cognitive function.
• Lumbar puncture – If leptomeningeal disease is suspected in addition to (or instead of) brain metastasis, a lumbar puncture may be performed to examine the cerebrospinal fluid for cancer cells.

What are the risk factors for lung cancer metastasis to the brain?

Several factors can increase the likelihood of lung cancer metastasis to the brain. These include:

• Lung tumor type – Certain lung cancer subtypes are more prone to brain metastasis, such as small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), particularly adenocarcinoma.
• Lung cancer stage – Advanced lung tumors (stages 3 and 4) are more likely to metastasize to distant organs, including the brain.
• Lung tumor genetics – Certain genetic mutations and alterations sometimes found in lung cancer, such as epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements, are associated with an increased risk of brain metastasis.
• The patient’s age and overall health – Young patients with specific genetic markers may live longer with lung cancer, increasing the likelihood of cancer spreading to the brain over time.
• Lack of early detection – Patients whose lung cancer was not detected early may develop metastases, including to the brain, before the disease is diagnosed or treated.

What is the prognosis for lung cancer metastasis to the brain?

In general, brain metastasis from lung cancer is associated with a more serious prognosis than a localized tumor that has not spread. However, various forms of treatment—including targeted therapy, immunotherapy, radiation therapy and surgery—continue to advance through research and clinical trials, helping many patients achieve the best possible outcome and quality of life.

Factors that can influence the prognosis for a patient with lung cancer metastasis to the brain include:

• Lung tumor type – When brain metastasis is present, patients with NSCLC tend to have a more favorable prognosis than those with SCLC.
• Molecular markers – Certain genetic mutations, such as EGFR or ALK, can open up more treatment options for lung cancer metastasis to the brain, potentially leading to a better outcome.
• Number of metastases – A patient with a limited number of brain metastases may be a candidate for localized treatment, such as stereotactic radiosurgery, which can improve the prognosis.
• The patient’s overall health and performance status – Patients in good general health are more likely to tolerate aggressive treatment and experience a better outcome.
• The patient’s response to treatment – A positive response to systemic therapy, especially targeted or immune-based treatments, can significantly improve the prognosis.

How is lung cancer metastasis to the brain treated?

Treatment for lung cancer that has spread to the brain is tailored to the patient and often involves a combination of therapies. The goals are to control cancer spread, relieve symptoms, preserve neurological function and improve quality of life. Options may include:

• Stereotactic radiosurgery (SRS) – A precise, high-dose form of radiation therapy, SRS can target one or a few small tumors with minimal impact on the surrounding healthy brain tissues.
• Whole-brain radiation therapy (WBRT) – If there are multiple brain metastases or SRS is not feasible, WBRT may be used to address both visible tumors and microscopic cancer cells by treating the entire brain.
• Surgery – Surgical removal of a single brain metastasis may be considered if the tumor is in an accessible location and the patient is in overall good health. Surgery is often followed by radiation therapy to help prevent cancer recurrence.
• Targeted therapy – If the primary lung tumor has a certain genetic mutation, such as EGFR or ALK, oral medications may help shrink or control the brain metastasis.
• Immunotherapy – This biological therapy can help the immune system recognize and attack cancer cells. It is being increasingly used for brain metastasis, particularly in patients with certain biomarkers, such as PD-L1.
• Chemotherapy – Traditional chemo is not commonly used for brain metastasis because the blood-brain barrier limits its efficacy; however, it may be effective in certain cases, particularly those involving small cell lung cancer.
• Supportive care – Corticosteroids can reduce brain swelling and alleviate the related symptoms, such as headaches and neurological changes, while anti-seizure medications may be prescribed if seizures occur. Physical therapy or rehabilitation can help the patient regain or maintain function and mobility.

Benefit from world-class care at Moffitt Cancer Center

If you would like to learn more about lung cancer metastasis to the brain, you can request an appointment with a specialist in Moffitt’s Neuro-Oncology Program by calling 1-888-663-3488 or submitting a new patient registration form online. We do not require referrals.