Accurate T staging in early gastric cancer (EGC) is critical because it determines treatment. Tumors limited to the mucosa (T1a) can often be treated with minimally invasive endoscopic procedures, while deeper tumors (T1b) usually require major surgery.
A new study found that EUS had an overall accuracy of about 75%. It was very good at confirming when a tumor was superficial (high specificity), but it was poor at ruling out deeper invasion (low sensitivity). As a result, nearly 59% of cancers that were actually limited to the mucosa were over-staged as deeper tumors. This means many patients could be recommended for unnecessary radical stomach surgery.
Researchers found that ulceration, younger age (under 50), and lower body mass index (BMI under 24) increased the risk of over-staging. Inflammation and fibrosis from ulcers can look like deeper tumor invasion on imaging. To avoid overtreatment, doctors should combine EUS with advanced optical imaging, such as magnifying endoscopy with narrow-band imaging, and consider diagnostic endoscopic resection for a definitive pathological diagnosis before deciding on major surgery.