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

We read with great interest the article by Kutup et al. [1], which presented their somewhat disappointing results with endoscopic ultrasound (EUS) staging of gastric cancer. In particular, in half of their patients with locally limited disease, EUS staging would have resulted in overtreatment. Kutup et al. concluded that “the diagnostic accuracy of EUS in the clinical staging of gastric and cardia carcinoma is limited.”

Overstaging, particularly of T stage, is a well-recognized issue in EUS [1]. However, the poor results of Kutup et al.’s study may be in part due to their lymph node criteria (two out of the following three features: size > 5 mm, round shape, smooth border). It is well known that lymph node size is, unfortunately, not a good predictor of malignant infiltration [2]. The use of EUS fine needle puncture (EUS-FNP) may overcome this drawback. However, a diameter of > 10 mm is the internationally most accepted metric parameter for likely tumor involvement. The criterion of 5 mm may have been responsible for the relatively fair specificity (57 %) noted by Kutup et al., without improvement in sensitivity (79 %) [1]. The same effect was reported in their previous study of EUS in esophageal cancer [3].

In our recent study with a similar design [4], which used a diameter of > 10 mm as the lymph node criterion, we were able to discriminate significantly better between locally limited and locally advanced disease: local staging with EUS was correct in 88 % of patients. Overstaging of locally limited disease occurred in 4 /19 patients, which is a much better result than that reported by Kutup et al. We also found that understaging of locally limited disease occurred in only 3 /43 patients. Thus, even in routine practice, reliable local staging of gastric cancer with EUS is possible.

From a clinical point of view, understaging of locally advanced carcinoma is more hazardous for the patient than is overstaging of locally limited disease. While we must keep in mind the limitations of EUS, it is still a reliable and valuable tool for local staging of gastric cancer, especially when considering the poor results obtained with alternative techniques such as computed tomography.

• References

• 1 Kutup A, Vashist K, Groth S et al. Endoscopic ultrasound in gastric cancer: does it help management decisions in the era of neoadjuvant treatment?. Endoscopy 2012; 44: 572-576
• 2 Nakamura K, Morisaki T, Noshiro H et al. Morphometric analysis of regional lymph nodes with and without metastasis from early gastric carcinoma. Cancer 2000; 88: 2438-2442
• 3 Kutup A, Link BC, Schurr PG et al. Qualitiy control of endoscopic ultrasound in preoperative staging of esophageal cancer. Endoscopy 2007; 39: 715-719
• 4 Bohle W, Scheidig A, Zoller WG. Endosonographic tumor staging for treatment decision in gastric cancer. J Gastrointestin Liver Dis 2011; 20: 135-139