What types of cancer commonly metastasize to the brain?

Common Cancer Types That Metastasize to the Brain

Lung cancer is the most common source of brain metastases, accounting for approximately 50% of all cases, followed by breast cancer, melanoma, renal cell carcinoma, and colorectal cancer. 1, 2

Primary Cancer Types by Frequency

Most Common Sources

• Lung cancer (both NSCLC and SCLC) represents the single largest contributor to brain metastases, responsible for roughly half of all cases 1, 2

  • Small cell lung cancer (SCLC) has particularly high rates, with autopsy series showing approximately 80% of SCLC patients develop brain metastases by time of death 1
  • Non-small cell lung cancer (NSCLC) also frequently metastasizes to the brain 1

• Breast cancer is the second most common primary source 2, 3

  • HER2-positive breast cancer carries especially high risk, with approximately 50% of patients who die from HER2-positive disease developing intracranial metastases 1
  • This high incidence has prompted prospective screening studies for advanced, metastatic, or inflammatory breast cancer 1

• Melanoma has the highest predilection for brain metastasis relative to its overall incidence, despite being less common than lung or breast cancer 2, 3

• Renal cell carcinoma and colorectal cancer are also recognized as common sources 2, 3, 4

Less Common But Notable Sources

• Testicular cancer 1
• Gastrointestinal primaries (beyond colorectal) 1
• Ovarian cancer 1
• Esophageal cancer 1

Rare Sources with High Brain Tropism

• Alveolar soft parts sarcoma 1
• Angiosarcoma 1
• Left-sided cardiac sarcoma 1

Important Clinical Context

Underestimation of True Incidence

The reported incidence for many cancers may be significantly underestimated because routine brain screening is not performed for most cancer types (unlike lung cancer, melanoma, and certain sarcomas) 1. For cancers like breast, renal, gastrointestinal, and head/neck primaries, brain metastases are often discovered only when symptomatic 1.

Unknown Primary

In up to 15% of patients presenting with brain metastases, no primary tumor can be identified despite thorough evaluation 2.

Temporal Development

A substantial proportion of patients without brain metastases at initial cancer diagnosis will develop intracranial disease during their clinical course 1. This delayed presentation underscores the importance of maintaining clinical vigilance even in patients with initially negative brain imaging 1.

Overall Burden

Brain metastases occur in approximately 8-10% of all cancer patients and represent the most common intracranial tumors in adults, occurring up to 10 times more frequently than primary brain tumors 2.