CHAPTER 19: Oncologic Emergencies

Brain metastases are common sequelae of solid tumors (lung, breast, melanoma, renal, and colorectal). Lung cancer has the highest number of brain metastases; however, melanoma has the highest propensity to metastasize to brain. Although their exact incidence is unknown, about 8%–10% of patients with cancer will manifest brain metastasis, with an expected growing incidence as a function of increased life expectancy.^1,2

Management is primarily local, owing to limited penetration of most systemic agents through the blood-brain barrier. The historical standard of care (whole-brain radiation therapy [WBRT]) is being rapidly replaced by focal techniques such as stereotactic radiosurgery (SRS) and surgical resection, alone or in combination.^1,3

A 48-year-old woman with a history of stage 2 triple-negative (ER– PR– Her-2-Neu–) breast cancer treated 3 years prior presents with headache and seizure. Imaging demonstrates a solitary 2-cm lesion in the left motor cortex.

• Assess prognosis; although the historical expected survival duration for patients with brain metastases is <1 year, at present multiple factors are used to assess prognosis, including

  • the extent of intracranial disease (number and volume of metastases)

  • the extent of extracranial disease (primary site control and/or presence of extracranial metastases)

  • histology and radiosensitivity

  • performance status^1,3

• A customized treatment plan should be tailored for each patient based on the above factors and should be discussed in a multidisciplinary team including medical oncology, radiation oncology, and neurosurgery^1,3

SRS offers a convenient method for the treatment of brain metastases that differs from traditional fractionated WBRT in both scope and adverse-effect profile. Published studies describe local control rates ranging from 70% to 90% for brain tumors smaller than 2 cm, dependent on histology. The control rates are lower for larger lesions, and sometimes a decision is made to combine surgery with SRS for such tumors.^1,3

SRS is preferred to WBRT due to comparable long-term overall survival,³ as well to decreased neurocognitive decline. Studies, including the most recent North Central Cancer Treatment Group N0574 trial, have demonstrated a decline in cognitive function in patients who received WBRT and SRS versus SRS alone.⁴ A recently published meta-analysis denoted decreased overall survival for patients receiving WBRT versus SRS alone, presumably due to neurocognitive dysfunction.⁵

Trials are being performed to determine the maximum number of lesions that can safely be treated with SRS. At present, the number is typically 4, but recent series have described a favorable safety profile in treating up to 10 brain metastases.⁶

• SRS is an emerging option for the treatment of brain metastases

• Palliative WBRT remains the standard of care for widely disseminated central nervous system disease, leptomeningeal disease, or poor performance status^1,3

1. National Comprehensive Cancer Network (NCCN) guidelines for central nervous system cancers. Version 1.2017. Available at: https://www.nccn.org.

2. Barnholtz-Sloan JS, Sloan AE, Davis FG, et al. Incidence ...