Researchers in SFU’s department of Molecular Biology and Biochemistry have refined the classification of a rare cancer called Burkitt lymphoma (BL) that they hope will result in more precise treatment options and improved survival rates for patients.
BL most often develops in children or young adults and is fatal if left untreated.
Currently, the classification of BL depends on where the patient resides. This is because the endemic variant of BL consistently occurs in regions where malaria is common, such as Africa and Papua–New Guinea, whereas the sporadic subtype develops in regions where malaria is not generally found.
The largest and most sweeping study of paediatric BL patients to date, SFU PhD candidate and study lead Bruno Grande and his team analyzed the genetic data of 106 BL patients from Africa, North America and Europe. They used a combination of whole-genome and transcriptome sequencing along with sophisticated computational methods to determine the molecular and genetic features of each patient.
The team discovered that the presence of the Epstein-Barr virus (EBV) in the tumour is key to understanding BL, regardless of where the patient resides.
Grande says, “We have known about a relationship between BL and EBV for over 50 years, but we didn’t fully understand how this effected the development of BL.”
EBV is present in more than 90 per cent of cases in malaria-endemic regions, and up to 30 per cent elsewhere.
“We examined tumours from all patients and found that EBV-positive tumours lacked important mutations in genes that play a role in apoptosis, also known as programmed cell death,” says Grande. “These data support a long-standing but unproven hypothesis that EBV disrupts apoptosis, and in turn, allows the tumour cells to grow into BL.”
BL is generally curable with intensive chemotherapy available in resource-rich countries. One-year survival rates for American children often reaches 90 per cent, which is double what is generally reached in some parts of Africa.
The study was funded by the National Cancer Institute ($2.9 million U.S.) with salary support from the Terry Fox Research Institute and has been published in the journal Blood.
Grande was drawn to the research after learning of the disparity in patient outcomes. “Most genomic research for BL has focused on the relatively curable and less common sporadic variant, despite the fact that most children who die from BL are endemic cases (i.e. cases from malaria-endemic regions such as equatorial Africa). This project was my way of trying to level the playing field in terms of research.”
Simon Fraser University