Researchers at the University of Manchester have identified two brief post-surgery time windows when chemotherapy drugs can penetrate the brain to treat glioblastoma.
Current medical guidelines recommend delaying chemotherapy and radiotherapy for four to six weeks following surgery to allow patients time to recover. However, laboratory experiments on mice demonstrated that administering treatment within minutes and days of tumor removal yielded the highest effectiveness in suppressing cancer regrowth.
The discovery centers on the blood-brain barrier, a natural protective filtering mechanism of blood vessels that normally stops most medications from entering brain tissue. Surgical intervention temporarily disrupts this protective shield, opening two distinct periods where anti-cancer therapies can pass through more easily to target residual cancer cells.
The blood-brain barrier consists of specialized endothelial cells lining brain capillaries that strictly regulate which micro-molecules enter central nervous system tissue. While it protects the brain from circulating toxins and infections, it also prevents more than 90 percent of systemic small-molecule drugs from reaching brain tumors under normal conditions.
Timing of post-surgery treatment
The study, published in the journal Science Translational Medicine and reported by The Independent, involved mouse models undergoing surgical procedures designed to replicate human glioblastoma removal. Researchers tested a drug that typically cannot cross the blood-brain barrier.
The research team established that the barrier becomes significantly more permeable at two specific intervals: approximately 15 minutes after surgery, and again between 48 to 72 hours following the operation. Delivering anti-cancer medication during these specific windows substantially inhibited the regrowth of the tumor.
Study co-author Dr Thomas Kisby said the project demonstrated for the first time that surgical removal of a glioblastoma creates a brief period of vulnerability in the tumor. He noted that administering drugs within these specific timeframes significantly restrained disease recurrence and opened possibilities to reuse existing medications more effectively without needing to develop entirely new drugs.
Professor Kostas Kostarelos, a researcher affiliated with both the University of Manchester and the Catalan Institute of Nanoscience and Nanotechnology in Barcelona, stated that the findings could establish a new direction in post-operative brain tumor treatment. He explained that glioblastoma most frequently recurs from cells lingering in the tissue immediately surrounding the surgical site.
Kostarelos suggested that clinicians could utilize advanced targeted drugs, nanoparticles, immunotherapy, and gene therapy during these post-operative windows to improve long-term patient survival rates. The Catalan Institute of Nanoscience and Nanotechnology in Barcelona specializes in nanoscale medical tools, including therapeutic delivery particles engineered to navigate complex biological barriers.
Need for clinical trials
Dr Gerben Borst, an oncologist at The Christie NHS Foundation Trust in Manchester, highlighted that destroying microscopic cancer cells remaining after surgery is the primary obstacle in glioblastoma treatment. He said a deeper understanding of the body's natural physiological response to surgery could help clinicians deliver treatments to tumors more effectively.
Borst cautioned that the findings represent an early stage of research and emphasized that clinical trials involving human patients are necessary before treatment protocols can change. The Christie NHS Foundation Trust is one of Europe's largest cancer treatment centers, specializing in advanced radiotherapy and experimental clinical trials.
Professor Robert Bristow, director of the Manchester Cancer Research Centre, described the study results as highly promising. He noted that glioblastoma remains the deadliest form of brain cancer and emphasized that the novel timing strategy could help prevent tumor recurrence following surgery.
Dr Simon Newman, chief scientific officer at The Brain Tumour Charity, also welcomed the findings. He said the research illustrates how the temporary opening of the blood-brain barrier could be exploited to deliver therapeutic agents directly into tumor sites, adding that human clinical trials must be the next step.
Glioblastoma impact and symptoms
Glioblastoma is recognized as the most aggressive and rapidly expanding form of primary brain cancer. In the United Kingdom, approximately 3,200 people are diagnosed with the condition each year, but only around 160 patients survive for more than five years after their initial diagnosis.
The tumor spreads rapidly across different areas of brain tissue. Key symptoms include severe headaches caused by elevated intracranial pressure, memory loss, personality changes, speech and comprehension difficulties, severe fatigue, depression, seizures, and visual impairment. Standard medical care currently relies on surgical resection of the tumor followed by chemotherapy and radiation therapy.
