According to findings of a national study led by a Yale Cancer Center (YCC) investigator, the addition of low-dose, whole-brain radiotherapy (LD-WBRT) combined with chemotherapy improved progression-free survival (PFS) in patients with primary central nervous system lymphoma (PCNSL). These results are to be presented May 30, during the virtual Scientific Program at the annual meeting of the American Society of Clinical Oncology (ASCO).
“PCNSL is a rare and hard to treat form of non-Hodgkin lymphoma that involves the brain and spinal cord,” said Antonio Omuro, M.D., director of the Brain Tumor Center at Smilow Cancer Hospital and Chief of Neuro-Oncology at YCC, and the lead author of the study. “Standard doses of radiotherapy are very toxic to the brain, but our study demonstrates that low doses of radiation can significantly benefit these patients.”
These discoveries raise the possibility that researchers may find safer and more effective therapies for PCNSL.
The study, sponsored by the NRG Oncology Cooperative Group, enrolled 87 patients across U.S. institutions. It randomly assigned them to receive either a chemotherapy combination consisting of rituximab, methotrexate, procarbazine, vincristine, and cytarabine (R-MPV-A) with LD-WBRT or R-MPV-A alone (chemo). Patients exhibited response rates of 81% (chemoRT) and 83% (chemo) following R-MPV-A. The 2-year PFS was 54% (chemo) and 78% (chemoRT). Longer-term survival data are still being collected. Neurotoxicity rates were not significantly increased between treatment arms and both arms had similar rates toxicities including anemia (27% overall), lymphopenia (41%), neutropenia (35%), thrombocytopenia (26%), ALT (23%), and AST (13%).
Researchers noted that further analysis of ongoing neurocognitive testing and imaging are needed to fully understand cognitive function.
The study was funded by the National Cancer Institute through the NRG Oncology Cooperative Group.