One and done
Among the 22 participants, 18 had neurologic symptoms at baseline. There were no new neurologic deficits that developed after GT placement.
In addition, GT therapy improved “local control” — preventing the tumor from growing back at the site of the surgery. The local control was 86% at 6 months and 81% at 12 months.
The median progression-free survival was about 8 months. The median overall survival was 20 months (about 600 days) for the unmethylated MGMT group and 37.4 months (about 1120 days) for the methylated group.
Outcomes compared favorably to an independent glioblastoma cohort of similar patients who did not receive GT treatment during the study period, Dr. Chen noted.
“This therapy can potentially redefine how we treat glioblastoma patients whose cancer came back,” he said.
A study limitation was that it did not include quality-of-life data, which makes it challenging to assess the therapy’s overall impact, Dr. Chen said. However, he added that from his experience, patients very much appreciate not having to repeatedly take time off work for clinic or hospital visits to receive radiation treatments.
“One of the beauties of this therapy is it’s a one-and-done deal,” he said.
Interesting, timely
Commenting for this news organization, William T. Curry Jr, MD, co-director at MassGeneral Neuroscience and director of neurosurgical oncology at Mass General Cancer Center, Boston, called the study “interesting and timely.”
These new data “underscore that GT is safe in patients that have undergone gross total resection of recurrent glioblastoma and that rates of progression free survival may exceed those treated with resection alone,” said Dr. Curry, who was not involved with the research.
“Surgeons are excited about anything that has the potential to improve outcomes for patients with this very challenging disease, and it is wonderful to be able to offer hope and survival tools to patients,” he added.
However, Dr. Curry noted there are challenges and potential biases when studying survival in cancer patients without conducting a randomization process. The investigators “admit to methodological flaws inherent in the single-arm design in a patient population with recurrent glioblastoma not treated uniformly,” he said.
In addition, he noted overall survival may not have been related to the GT intervention. “Multicenter randomization is probably required to get to the bottom of the survival advantage in different subsets of glioblastoma patients,” Dr. Curry said.
Further research is needed to confirm the efficacy, appropriate indications, and timing of the intervention, but “I would support a randomized multicenter study in patients undergoing near gross total resection of recurrent glioblastoma,” he concluded.
The study received no outside funding. Dr. Chen and Dr. Curry have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.