Recent advances in genomic sequencing have revealed that 5–15% of children with cancer have an underlying genetic predisposition.
Although genetic predispositions increase the risk for new tumors, it has been unclear when to begin surveillance for these tumors. St. Jude Children’s Research Hospital scientists showed that beginning surveillance soon after recognizing a patient’s predisposition often led to discovering one or more early-stage asymptomatic tumors. About half of these tumors could be completely removed by surgery alone, thus avoiding the need for toxic chemotherapies or radiation therapies. The findings inform clinical practice after genetic testing and were published in JAMA Oncology.
Findings showed the benefit of early surveillance applied across multiple cancer types and predisposing conditions. The researchers examined 274 St. Jude pediatric patients with 35 different cancer-predisposing conditions over a median of three years. Surveillance revealed tumors in 27 patients, representing a broad array of solid and central nervous system neoplasms.
Most of the new cancers detected in the study were found with early surveillance right after the genetic predisposition was discovered. Nearly one out of every three tumors were found at the first surveillance intervention soon after diagnosis, and two out of three were found within two years of that initial surveillance visit. Surprisingly, this included a small subset of children already being treated for a different cancer.
Beginning surveillance right away also resulted in finding cancers in earlier stages. Without the early screening, many of the tumors would have remained unnoticed until much later because almost all were asymptomatic at the time of discovery. By finding these tumors at an early stage, oncologists could remove most of them by surgery alone. In addition, findings showed that most tumors (around 70%) were entirely removed without leaving even microscopic traces behind.
To find potential cancers and guide treatment, clinicians used various surveillance methods. For example, a predisposition for a solid tumor may lead to annual full-body magnetic resonance imaging (MRI). Standard surveillance methods had minuscule false positive and false negative rates.
