Preoperative diagnosis of tumor depth in gastric cancer using transabdominal ultrasonography compared to using endoscopy and computed tomography.

Abstract

An accurate evaluation method for preoperative diagnosis has not yet been established in patients with gastric cancer (GC), though it is essential for optimal treatment. Current standard modalities are endoscopy and contrast computed tomography (CT). In this study, we investigated the efficacy and limitations of transabdominal ultrasonography (TUS) for the assessment of tumor invasion. We enrolled 178 consecutive patients with GC evaluated by TUS, endoscopy, and contrast CT before gastrectomy. For the TUS examination, patients ingested water to fill their stomachs. The clinical staging determined using these modalities was compared to the pathological staging. The overall accuracy of clinical T staging using TUS was 47.8% (pT1a: 5.8% (2/35); pT1b: 58.8% (20/35); pT2: 69.6% (16/23); pT3: 66.7% (22/33); pT4a: 46% (23/50); pT4b: 100% (2/2)). Using endoscopy, contrast CT, and TUS, the overall accuracy was 60.7%. The accuracy of TUS was associated with the tumor region (U region: 50% (14/28); M: 31.8% (14/44); L: 53.7% (57/106); P = 0.048), but not with the cross-sectional parts (P = 0.49). Multivariate analysis identified inaccurate TUS as independently correlating with tumor region (M vs. U/L, odds ratio (OR) = 3.11, 95% confidence interval (CI) 1.41-6.87; P = 0.005) and pT (pT1 vs. pT2-4, OR = 3.00, 95%CI 1.31-6.87; P = 0.009). The present study demonstrated the importance of TUS in evaluating GC. Thus, TUS may be useful for clinical T staging in certain circumstances, leading to treatment optimization.