A new perspective published in The Lancet Oncology is challenging the way doctors and scientists understand and treat metastatic brain cancer.

Traditionally seen as just the spread of cancer from another part of the body, brain metastases are now being recognised as something much more complex—a disease of the brain itself.

Led by Dr. Jawad Fares and colleagues at Northwestern University, the article argues that brain metastases should be treated as their own distinct condition rather than simply an offshoot of other cancers.

This shift in thinking could revolutionise research, unlock new treatments, and ultimately improve survival and quality of life for patients.

“We’ve long approached metastatic brain cancer as a secondary issue, treating it like its original tumour,” said Dr. Fares.

“But our research shows that these tumours have unique characteristics that make them more than just a ‘spread’ of cancer—they are brain diseases in their own right.”

Key takeaways: 

• Brain metastases are not just “spread” cancer – Tumour cells that reach the brain undergo major changes that make them different from their original cancer. They adapt to survive in the brain’s environment, evade the immune system, and resist treatment.
• The blood-brain barrier is a major challenge – The brain has a natural shield that blocks most drugs, making it harder to treat brain metastases with standard cancer therapies. New treatments must be designed specifically to cross this barrier.
• Current research and clinical trials are outdated – Many cancer treatments are tested on primary tumours but don’t account for how brain metastases behave differently. Brain cancer patients are often left out of clinical trials, limiting progress.
• A new approach could change everything – By treating brain metastases as their own disease, scientists can develop better, more targeted treatments, focus on early detection, and push for research funding specific to brain cancer.

A Call for Change

This new perspective urges researchers, doctors, and policymakers to rethink how they approach metastatic brain cancer. It’s not just about changing definitions—it’s about saving lives.

“If we continue treating brain metastases as an afterthought, we will never make the progress patients need,”Dr. Fares explained. “It’s time for a dedicated approach that focusses on the unique challenges of brain cancer.”

The full article is now available in The Lancet Oncology.

Reference: Fares, Jawad, et al. "Rethinking Metastatic Brain Cancer as a CNS Disease"; The Lancet Oncology, vol. 26, no. 2, 2025, pp. e111–e121, https://doi.org/10.1016/S1470-2045(24)00430-3.

Source: Northwestern University