Dear editor,

We read with particular interest the paper by Nakamura et al.1 published in Annals of Surgical Oncology in November 2018.

We are greatly surprised by the excellent survival outcomes shown in both trials. As a matter of fact, pStage 3 patients exhibited a 3-year overall survival (OS) of about 75% to 80%. These patients are really incredible compared with Western patients.

In our Italian surgical center, pStage 3 relapse-free survival (RFS) and OS results are worse. In the last survival analysis, pStage 3C patients showed a survival comparable with stage 4 survival according to the newest 8th tumor-node-metastasis (TNM) staging system. Our results are similar to those of other centers in Western and Eastern countries.2

Also, In3 in his recent work described a poor 3-year OS ranging from 40 to 13% for pStage 3 patients after curative surgery. In addition, we well know that adjuvant chemotherapy does not add such a large survival benefit, highlighting the important and predominant role of surgery with an adequate lymphadenectomy in the treatment of locally advanced gastric cancer.4

We are convinced that gastric cancer in the East differs biologically from gastric cancer in the West, but we cannot explain how pStage 3 disease has such a long 3-year RFS and a percentage so different from ours. This cannot be explained only by the use of S1, a drug not available in Italy to date.

It could be useful to separate pStage 3 into stages 3a, 3b, and 3c according to the 8th TNM staging system to discriminate the real subgroup of patients that could benefit from adjuvant chemotherapy after gastric resection. Probably, this would not have been possible with the small studied population.

We will use a longer follow-up period to observe possible survival outcomes or to confirm them. In the future, molecular investigations must be conducted for a better understanding of the biologic differences and behaviors between East and West.