Researchers from the National Cancer Institute’s (NCI ) Centre for Cancer Research and Washington University School of Medicine have developed a blood test that can enable the early detection of cancer in people with neurofibromatosis type 1 (NF1).

NF1 is the most common cancer predisposition syndrome. Commonly diagnosed in childhood, it is caused by a mutation in a gene called NF1.

The new blood test is also expected to help doctors monitor how well patients are responding to treatment for their cancer.

At present, doctors use either imaging scans, such as MRI or PET scans, or biopsies to determine if plexiform neurofibromas have transformed into malignant peripheral nerve sheath tumours (MPNST).

For the study, scientists collected blood samples from 23 people with plexiform neurofibromas, 14 patients with MPNST who were yet to be treated, and 16 healthy people without NF1.

The researchers separated cell-free DNA from the blood samples and used whole-genome sequencing technology to look for differences in the genetic material among the three groups.

The differences found in the study allowed the researchers to differentiate, with 86% accuracy, between those patients with plexiform neurofibromas and those with MPNST.

NCI pediatric oncology branch Lasker scholar and study co-author Jack Shern said: “This blood test could easily and rapidly allow us to determine whether the disease is going down or maybe even going away entirely.

“And if you had done surgery and taken out an MPNST, and the blood test was negative, you could use that to monitor the patient going forward to see if the tumour returns.”

These types of blood tests help in the early detection and monitoring of patients with other cancer-predisposing genetic disorders, including multiple endocrine neoplasia.