Study Finds Link Between Histone Levels and Efficacy of Radiation Therapy
Posted: Monday, May 21, 2018
In patients with breast cancer, prognosis appears to be worse if expression levels of histone H2AX are high. Surprisingly, tumors that express high levels of H2AX also seem to be more sensitive to radiation therapy. Eriko Katsuta, MD, PhD, and colleagues, of the Roswell Park Comprehensive Cancer Center, presented these findings at the 2018 American Association for Cancer Research (AACR) Annual Meeting (Abstract 3216/22). The investigators believe H2AX may prove to be a prognostic biomarker for recurrent tumors that may respond to radiation therapy.
“The association between H2AX and a poor outcome was significant for all breast cancer patients, especially those with advanced disease,” said Dr. Katsuta in a Roswell Park press release. “We found that H2AX is involved in several different pathways leading to the development of breast cancer.”
The tumors analyzed for this research belonged to over 11,000 patients registered in The Cancer Genome Atlas. H2AX gene expression levels were determined via RNA sequencing, and radiation sensitivity was quantified using cells from patient-derived xenograft.
The investigators found a higher expression of level of H2AX in triple-negative breast cancers (TNBCs) than in non-TNBCs (P < .001) and in HER2-positive tumors than HER2-negative tumors (P = .048) as well as advanced-stage tumors (P = .029). In addition, cells that expressed higher levels of H2AX seemed to be more sensitive to radiation therapy.