The first genetic marker for the bone tumour, osteoblastoma, has been discovered by scientists at the Wellcome Sanger Institute and their collaborators. Whole-genome and transcriptome sequencing of human bone tumours revealed that a genetic change that affects the transcription factor, FOS, is a hallmark mutation of osteoblastoma.
The results, published in Nature Communications in a report co-lead authored by Professor Adrienne Flanagan from the UCL Cancer Institute and the RNOH, and Dr Sam Behjati from the Wellcome Sanger Institute and the University of Cambridge, will help clinicians correctly distinguish benign osteoblastoma tumours from aggressive osteosarcoma tumours and direct the correct treatment.
Osteoblastoma is the most common benign tumour of the bone, mainly affecting children and adults between the ages of 10 and 25. It is treated by surgical removal of the tumour, however the diagnosis of osteoblastoma can be challenging. Under the microscope, osteoblastoma tumours can look very similar to osteosarcoma, an aggressive form of bone cancer that requires extensive treatment, sometimes including amputation or significant surgery and chemotherapy.
In this new study, scientists from the Wellcome Sanger Institute and their collaborators at the UCL Cancer Institute and Francis Crick Institute discovered a genetic mutation that distinguishes osteoblastoma from osteosarcoma.
To explore whether their result could be useful as diagnostic markers for osteoblastoma, scientists examined the whole genome sequences of 55 osteosarcoma cases and found none of the samples harboured mutations in FOS or FOSB. When the team analysed over 2,500 non-osteoblastoma tumours, they again did not find similar mutations, meaning the FOS and FOSB mutations are specific to osteoblastoma.
Dr Sam Behjati, co-lead author, said: "The main clinical challenge when diagnosing osteoblastoma can be to reliably distinguish these tumours from osteosarcoma. These two forms of bone tumour require very different treatments: osteoblastoma tumours just need removing to ease symptoms, whereas osteosarcomas is treated aggressively with surgery and intensive chemotherapy. For the first time, we have discovered a specific mutation that defines osteoblastoma."
Dr Matthew Fittall, co-first author from the Francis Crick Institute, UCL Cancer Institute and Wellcome Sanger Institute, said: "We have known for a while that FOS is involved in the progression of bone tumours, however, we have not found mutations of FOS in human bone-forming tumours before. Using genomic sequencing we have shown that mutations in FOS and its relative FOSB are diagnostic markers of osteoblastoma."
Professor Adrienne Flanagan, co-lead author, said: "Genomics is transforming our understanding of cancers. Our discovery of the genetic mutation that characterises osteoblastoma will help clinicians diagnose it with more confidence and direct the correct treatment."
Contact details:Emily Mobley
Wellcome Sanger Institute
Cambridge, CB10 1SA
Phone: 01223 496851