Preoperative accuracy of gastric cancer staging in patient selection for preoperative therapy: race may affect accuracy of endoscopic ultrasonography

Abstract

Background: Over the last 15 years, large randomized controlled studies have validated the benefit of preoperative therapy for patients with resectable gastric cancer. Computed tomography (CT) and endoscopic ultrasonography (EUS) are commonly used to select patients for preoperative treatment, but studies of preoperative staging accuracy that focus on patient selection for preoperative therapy are rare; therefore, whether CT or EUS can reliably identify patients eligible for preoperative therapy is still unclear. Our purpose was to determine the accuracy of EUS and CT for preoperative staging of gastric cancer and to identify factors that may affect their usefulness in selecting patients for preoperative therapy. Methods:We reviewed the medical records of 8,260 patients with gastric or gastroesophageal adenocarcinoma treated at our institution from 1995 to 2013, identifying those who underwent gastrectomy without preoperative treatment. We compared T stage and N status from preoperative EUS and CT reports with those drawn from surgical pathology reports. Clinicopathologic and demographic variables associated with incorrect preoperative staging were investigated using univariate and multivariate analyses. Results:We identified 187 patients who underwent preoperative staging by EUS (n=145) and/or CT (n=134) before gastrectomy. The accuracy, sensitivity, and specificity of EUS in distinguishing stage T1 from more advanced tumors were 82%, 78%, and 85%, respectively. Variables associated with underestimation of EUS T stage were lymphovascular invasion [odds ratio (OR), 7.51; 95% confidence interval (CI), 1.91-29.50; P<0.01] and white race (OR, 3.75; 95% CI, 1.31-10.75; P=0.01). The accuracies, sensitivities, and specificities for determining N status were, respectively, 65%, 49%, and 79% with CT and 66%, 29%, and 95% with EUS. Lymphovascular invasion was associated with a false negative result (OR, 3.79; 95% CI, 1.34-10.70; P=0.01), and well-or moderately differentiated histology was associated with a false positive result for CT N status (OR, 7.14; 95% CI, 2.00-25.44; P<0.01).Conclusions: EUS is accurate in distinguishing T1 from T2-T4 lesions; both CT and EUS have low sensitivities and high specificities in determining N status. These accuracies and variables associated with inaccurate staging, including race, should be considered when selecting gastric cancer patients for preoperative therapy.

Endoscopic Ultrasonography Miniature Probe Performance for Depth Diagnosis of Early Gastric Cancer with Suspected Submucosal Invasion

“…Several studies have mentioned the sensitivity for SM2 or deeper EGC by EUS ranging from 66.3% to 84.0%, 17 , 20 , 21 similar to the findings in our study.…”

“…In some previous reports, EUS examinations were performed by conventional EUS or miniature probe. 20 , 21 , 23 This is one of the reasons that the upper-third stomach location was not a risk factor of misdiagnosis in our study, because it is often difficult to scan lesions located in the upper-third of the stomach using conventional EUS, while we have used only the miniature probe for EUS examination. The “0-I” macroscopic subtype has also been reported to be a factor for misdiagnosis, 13 , 15 however, macroscopic features had no relationship to misdiagnosis in our study.…”

“…With regards to study subjects, we only included EGCs suspicious for SM invasion, while other studies have included a high number of muscularis propria gastric cancers. 18 , 20 , 21 , 25 EUS examination is not necessary in practice for lesions in which the depth diagnosis is evident based on endoscopic evaluation because of time and procedure related costs. Our study analysis only focused on EGC suspicious of SM invasion.…”

The ypT category does not impact overall survival in node negative gastric cancer

“…This finding contrasts with previous findings by Zanoni et al who analyzed patients with esophageal cancer and found that patients with “downstaged N0” disease had worse OS than those with “natural N0” disease, although the study did have a limited number of patients. The limited survival impact of cN status may be caused by inaccuracy of preoperative cN staging in gastric cancer patients, as reported before; however, such inaccuracy surely exists in the real world and needs to be taken into account. On the basis of the available data, achievement of ypN0 status appears to be an important predictor of good OS in gastric cancer.…”

Staging laparoscopy and peritoneal cytology in patients with early stage gastric adenocarcinoma

“…Another aspect our study reveals is the importance in recognizing the established limitations of preoperative staging in reliably identifying early stage disease. Ikoma et al demonstrated limited accuracy of EUS at determining actual T stage, as well as both computed tomography (CT) and EUS having low sensitivities in determining N status [37]. We feel that under-staging may have contributed to the relatively large number of early stage patients with peritoneal carcinomatosis, and therefore we have limited confidence in foregoing peritoneal staging based on preoperative staging.…”