Background: There is a need to assess the sensitivity, specificity, and predictive value of endoscopic ultrasonography (EUS) in the diagnosis and staging of gastric cancer and lymphoma.
Methods: A prospective study was performed on 86 patients with endoscopic gross appearance suspicious for cancer or lymphoma. Biopsies with endoscopic forceps were always carried out before EUS. All patients underwent laparotomy for final diagnosis, staging, and eventually treatment. The results of EUS were correlated with the histologic findings of the resected specimens, when possible, or with the surgical findings. There were 42 gastric cancers and 44 primary gastric lymphomas.
Results: EUS made a correct diagnosis of cancer in 35 of 42 patients, with a sensitivity of 83%. Positive predictability was 87%, specificity was 97%, and negative predictability was 96%. Diagnostic accuracy was 95%. In the evaluation of cancer depth invasion, EUS was correct in 91% of cases. EUS displayed perigastric metastatic lymph nodes in 14 of 25 patients, with a sensitivity of 56%. Positive predictive value was 93%, specificity was 93%, and negative predictive value was 54%. Diagnostic accuracy was 69%. EUS made a correct diagnosis of lymphoma in 39 of 44 patients, with a sensitivity of 89%. Positive predictability was 87%, specificity was 97%, and negative predictability was 97%. Diagnostic accuracy was 95%. In the evaluation of lymphoma depth invasion, EUS was correct in 92% of cases. EUS displayed metastatic perigastric lymph nodes in 8 of 18 patients, with a sensitivity of 44%. Positive predictability was 100%, specificity was 100%, and negative predictability was 72%. Diagnostic accuracy was 77%.
Conclusions: From these data it appears that in these diseases EUS has demonstrated specific ultrasonographic features that allow correct diagnosis and staging in the majority of patients. In difficult cases EUS may help to achieve the correct diagnosis. EUS also appear to be a useful tool for staging of gastric cancer and lymphoma. It shows not only tumor depth and local spread but also the passage from a pathologic to a normal wall and lymph node metastasis. With this accurate noninvasive staging procedure, in the near future many patients will no longer undergo exploratory laparotomy for surgical staging. Thanks to EUS, the choice of conservative or surgical treatment can be strongly affected. In case of surgery, EUS can orient the kind of surgical approach. Moreover, the use of EUS for evaluation of therapy during follow-up will probably become of major importance.