In a common genetic disorder, a blood test reveals when benign tumours turn cancerous
People with an inherited condition known as neurofibromatosis type 1, or NF1, often develop non-cancerous, or benign, tumours that grow along nerves. These tumours can sometimes turn into aggressive cancers, but there hasn’t been a good way to determine whether this transformation to cancer has happened. Researchers from the National Cancer Institute’s (NCI) Center for Cancer Research, part of the National Institutes of Health, and Washington University School of Medicine in St. Louis have developed a blood test that, they believe, could one day offer a highly sensitive and inexpensive approach to detect cancer early in people with NF1. The blood test could also help doctors monitor how well patients are responding to treatment for their cancer. The findings are published in the August 31 issue of PLOS Medicine. NF1 is the most common cancer predisposition syndrome, affecting 1 in 3,000 people worldwide. The condition, caused by a mutation in a gene called NF1, is almost always diagnosed in childhood. Roughly half of the people with NF1 will develop large but benign tumours on nerves, called plexiform neurofibromas. In up to 15% of people with plexiform neurofibromas, these benign tumours turn into an aggressive form of cancer known as malignant peripheral nerve sheath tumour or MPNST. Patients with MPNST have a poor prognosis because cancer can quickly spread and often becomes resistant to both chemotherapy and radiation. Among people diagnosed with MPNST, 80% die within five years. “Imagine going through life with a cancer predisposition syndrome like NF1. It’s kind of like a ticking bomb,” said study co-author Jack F. Shern, M.D., a Lasker Clinical Research Scholar in NCI’s Pediatric Oncology Branch. “The doctors are going to be watching for cancerous tumours, and you’re going to be watching for them, but you really want to discover that transformation to cancer as early as possible.” Doctors currently use either imaging scans (MRI or PET scan) or biopsies to determine if plexiform neurofibromas have transformed into MPNST. However, biopsy findings aren’t always accurate and the procedure can be extremely painful for patients because the tumours grow along nerves. Imaging tests, meanwhile, are…
