Dr. Shiller on Next-Generation Sequencing in GI Cancers

Shirley Michelle Shiller, DO, member of the Precision Medicine Institute's Advisory Committee, Baylor University Medical Center, discusses next-generation sequencing (NGS) in gastrointestinal malignancies.

NGS was launched around 2011, and at that time, most people in the field were still doing single-gene testing, says Shiller. She says that this was due to the power of NGS not being fully understood. NGS requires less tissue, and allows for the interpretation of multiple genes at one time. If a patient is very sick, Shiller says that NGS can answer multiple questions at one time with one tissue source. It is also more sensitive.

There has been a shift in recent years toward using NGS. Single-gene assays do still exist, but require more DNA than most of the NGS-based assays, explains Shiller. Two of the significant molecular aberrations to identify in gastrointestinal cancers are mismatch repair deficiency and microsatellite instability, as they can guide treatment decision.