Endoscopic ultrasound staging in gastric cancer: Does it help management decisions in the era of neoadjuvant treatment?

BACKGROUND AND STUDY AIMS

Endoscopic ultrasonography (EUS) has been shown to be the most accurate test for locoregional staging of upper gastrointestinal tumors; however, recent studies have questioned its accuracy level in daily clinical application. The present retrospective study analyzes the accuracy of EUS in guiding interdisciplinary treatment decisions.

PATIENTS AND METHODS

123 primarily operated patients (63 % men, mean age 61.4 years) were included; only cases with tumor-free resection margins and without evidence of distant metastases were selected. EUS and histopathological findings were compared. Main outcome parameter was the distinction between tumors to be primarily operated (T1 /2N0) and those to be treated by neoadjuvant or perioperative chemotherapy (T3/4, or any N + ), based on an assumed algorithm for treatment stratification.

RESULTS

Overall staging accuracy of EUS was 44.7 % for T and 71.5 % for N status irrespective of tumor location. Overstaging was the main problem (44.9 % for T, 42.9 % for N staging). The overall EUS classification was correct in 79.7 % (accuracy), with a sensitivity 91.9 % and specificity 51.4 %; only 19 out of 37 cases with histopathological T1/2N0 were correctly classified by EUS. Positive and negative predictive values of EUS in diagnosing advanced tumor stage for assignment to neoadjuvant therapy were 81.4 % and 73.1 %, respectively.

CONCLUSIONS

Whereas EUS has a high sensitivity in the diagnosis of locally advanced gastric cancer, endosonographic overstaging of T2 cancers appears to be a frequent problem. EUS stratification between local (T1 /2N0) and advanced (T3/4 or any N + ) tumors would thus result in incorrect assignment to neoadjuvant treatment in half of cases.