Prognostic relevance of gastric cancer staging by endoscopic ultrasound

Recent trials and guidelines have established the use of neoadjuvant chemotherapy for resectable UICC stage II to IV gastric cancers. In this setting, preoperative staging is pivotal for correct patient selection. This cohort study was designed to assess the accuracy of endoscopic ultrasound (EUS) and the ability to select correctly patients for neoadjuvant chemotherapy on the basis of survival outcome.

Eighty-two consecutive Caucasian patients (46 male; median age 72 years) with gastric cancer underwent EUS staging and subsequent surgery without perioperative chemotherapy or radiotherapy. Patients were followed for a median of 800 days postoperatively. Pathology and EUS UICC and T stages were compared and evaluated as predictors of survival using Kaplan-Meier and Cox regression analysis.

The overall accuracy of EUS for UICC classification compared with pathology was 62 %, and the accuracy for delineation of UICC I was 89 %. For the therapeutically relevant differentiation of early gastric cancer (UICC stage I), EUS (mean survival, 2,298 days, R2 = 0.23) and pathology (2,461 days, R2 = 0.24) predicted survival equally well. Similar results were obtained for T staging by EUS (mean survival, 2,065 days for uT1/2, R2 = 0.24) or pathology (2,185 days, R2 = 0.22).

EUS identifies the low risk subgroup (uUICC stage I or uT1/2) with similar performance as pUICC stage I or stage pT1/2 in gastric cancer and very similar survival characteristics. EUS thus may be the noninvasive method of choice for preoperative selection of patients for immediate resection versus neoadjuvant chemotherapy.