By: Michele W Sequeira
All types of brain cancers collectively have a five‑year survival rate of just 33%, according to the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program. For a type of brain cancer called glioblastoma, however, the five-year survival rate is 7%, according to Sara G. M. Piccirillo, PhD, a tenure‑track assistant professor in the Department of Cell Biology and Physiology at The University of New Mexico School of Medicine and a full member of the UNM Comprehensive Cancer Center.
Piccirillo said the survival rate remains low because glioblastoma almost always grows back. Even after surgery, radiation, chemotherapy and electric field therapy, the tumors recur, and surgeons often cannot safely remove them all.
Piccirillo focuses her research on residual glioblastoma disease, the brain cancer cells that remain after treatment has ended.
In earlier research, Piccirillo showed that cells in glioblastoma tumors differ from one another, even within the same tumor. She said this extreme cell variation makes the tumors prone to recurring. Although some cells respond to therapy, others do not.
These surviving cells, Piccirillo explained, can restart a tumor and may also resist previous therapies, which limits treatment options.
Piccirillo’s team found that in 65% of people with glioblastoma, unremoved tumor cells reside in a specific brain region called the sub‑ventricular zone. The team described the role of this region as a reservoir of glioblastoma cells in their research article, “Single-nucleus and spatial landscape of the sub-ventricular zone in human glioblastoma,” published in Cell Reports in January 2025.
Piccirillo’s research on the sub‑ventricular zone also highlighted a second factor in glioblastoma recurrence: microglia. These immune cells surround the residual glioblastoma cells. Normally, microglia collect and remove waste from brain cells and defend the brain against cancer and infection. Piccirillo found that in the sub‑ventricular zone, microglia help glioblastoma tumors grow.
Piccirillo is now studying how glioblastoma cells isolated from sub‑ventricular zone tissues differ from cells isolated from tumor tissues. Her goal is to identify molecular and genetic differences that might cause glioblastoma cells in the sub‑ventricular zone to respond differently to therapy. She plans to use these findings to develop personalized approaches to prevent recurrence.
