When Lung Cancer Spreads to the Brain

Symptoms, Diagnosis, and Advances in Treatment

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Lung cancer is known to spread to the brain in about 40 percent of cases in which metastasis has occurred. Metastasis is the medical term used to describe a cancer which has spread beyond the initial tumor to a different, distant organ system.

Overview

When this happens in people with lung cancer, the secondary malignancy is not considered a "brain cancer" but rather a "lung cancer metastatic to the brain." By contrast, a brain cancer is only those which originate in the brain as the primary, rather than secondary, malignancy.

Sadly, those with secondary brain cancer have a median survival of only four months. With that being said, in cases where the brain involvement is small (sometimes defined as oligometastases), the rate can be significantly higher with more than 60 percent surviving for two years or longer.

Symptoms

Secondary brain malignancies can be caused by either small cell lung cancer and non-small cell lung cancer. Small cell lung cancer is often difficult to diagnose in the early stages and, as a result, can spread to the brain before a diagnosis is even made. Non-small cell lung cancer can also metastasize to the brain but typically does so in later, stage 4 disease.

Symptoms can vary by both by the type of lung cancer involved and the stage in which the diagnosis is made. Frustratingly, as many as a third of all people with secondary brain cancer will have no symptoms whatsoever. If they do occur, they typically include:

  • Headaches
  • Fatigue
  • Loss of balance
  • Nausea and vomiting
  • Difficulty walking
  • Loss of coordination
  • Speech problems
  • Vision changes, including loss of vision or double vision
  • Peripheral weakness (occurring on one side of the body)
  • Memory loss
  • Personality changes
  • Seizures

Diagnosis

If your doctor suspects that your lung cancer has spread to the brain, he or she will order imaging tests such as computed tomography (CT scan) which use X-ray to create diagnostic images or a magnetic resonance imaging (MRI) which does the same with magnetic waves.

While an MRI is considered more accurate, it may not be used in persons with certain metal implants (including non-safe pacemakers).

Another type of imaging tool is positron emission tomography (PET scan) which is able to differentiate between normal cell metabolism and those which appear hyperactive (such as cancer cells). If a suspicious lesion is found but the diagnosis is uncertain, a biopsy may be performed to obtain a tissue sample for evaluation.

Treatment

The treatment of secondary brain cancer depends on a number of factors including how much of the brain is involved and your overall health. Since it is usually not possible to get rid of secondary brain cancer in its entirety, treatment is focused on controlling the complications of the disease while optimizing the quality of life first and foremost.

Steroids such as Decadron (dexamethasone) may be used to control any swelling of the brain, while anticonvulsive medications can reduce the incidence and severity of seizures. Among the options that specifically treat the cancer:

  • Whole-brain radiotherapy is typically the treatment of choice if a tumor can’t be seen or more than three are identified. It can also be used after surgery to reduce further spread of the cancer. While not designed to cure cancer, at least 50 percent of people undergoing whole-brain radiotherapy will notice some improvement in symptoms. Common side effects can include memory loss (especially verbal memory), skin rash, and fatigue.
  • Stereotactic radiotherapy (also known as stereotactic radiosurgery) is a type of high-dose radiation given to a specific area of the brain. Since the radiation is targeted, side effects are typically less severe and offer better survival rates than whole-brain therapy. This form of radiotherapy is usually reserved for people with three or fewer tumors.
  • Surgery may be an option if there are one or a couple of tumors that are easily accessed, and there are no signs of cancer elsewhere. Surgery may involve the complete removal of a tumor or the partial removal to alleviate symptoms. Whole-brain radiation typically follows. Since small-cell tumors are more responsive to radiotherapy alone, surgery is more often used to remove non-small cell cancers.
  • Chemotherapy is not as effective in treating secondary brain cancer as the drugs are less able to penetrate the blood-brain barrier which surrounds the brain.

If the various treatment options prove ineffective, palliative care may be used to offer relief and reduce stress associated with a terminal diagnosis. This may include the use of pain medications, physical and occupational therapy, or complementary treatments to enhance comfort and improve the quality of life.

A Word From Verywell

Brain metastases due to lung cancer can be terrifying. But, as scary as it may be, it's important to remember that there is no set course when it comes to cancer. It can vary from person to person, and the "median" or "average" expectancies you'll read about don't necessarily apply to you as an individual.

If faced with a secondary brain tumor, work with your doctors and loved ones to make the most informed choice based a full and honest disclosure of information. It's important to allow yourself to feel what you feel and to seek support to help navigate this journey. Just take it one step at a time.

Sources:

Gaspar, L.; et al. "The Role of Whole Brain Radiation Therapy in the Management of Newly Diagnosed Brain Metastases: A Systematic Review and Evidence Based Clinical Practice Guideline." Journal of Neuro-oncology. 2010; 96(1):17-32.

Kalkanis, S., et al. "The Role of Surgical Resection in the Management of Newly Diagnosed Brain Metastases: A Systematic Review and Evidence-Based Clinical Practice Guideline." Journal of Neuro-oncology. 2010; 96(1):33-43.

Linskey, M.; et al. "The Role of ​Stereotactic Radiosurgery in the Management of Patients With Newly Diagnosed Brain Metastases: A Systematic Review and Evidence-Based Clinical Practice Guideline." Journal of Neuro-oncology. 2010; 96(1):45-68.

Mehta, M.; et al. "The ​Role of Chemotherapy in the Management of Newly Diagnosed Brain Metastases: A Systematic Review and Evidence-Based Clinical Practice Guideline." Journal of Neuro-oncology. 2010; 96(1):71-83.

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