We find Hottenrott’s letter [1] most interesting as he states that lymph node status was one of the prognostic factors in previous reports on gastric cancer. Preoperative lymph node status in the present study was evaluated by endoscopic ultrasonography and computed tomography. The performance found was similar to that of prior studies, in which results ranged from 67 to 90% [2, 3]. The rates of accuracy for depth of tumor and lymph node status in our study were 78 and 71%, respectively. The N/L ratio has been shown to have an independent prognostic value in a variety of cancers, including lung, colorectal, pancreatic, and ovarian cancers and cholangiocarcinomas. Although ours was a retrospective study, our prognostic model is expected to predict cancer-related prognosis of gastric cancer. We will validate how this prognostic model is useful for large prospective studies.

Various new therapeutic approaches have been introduced with the aim of improving survival and quality of life. In patients with early gastric cancer, especially where disease is confined to the mucosa, endoscopic resection is performed to avoid unnecessary surgical procedures [4]. To achieve R0 resection for locally advanced gastric cancer, neoadjuvant treatments have been investigated [5]. At present there are no serum biomarkers that are sufficiently sensitive or specific for personalized gastric cancer therapies. Proteomic approaches can characterize hundreds to thousands of proteins in clinical samples and reveal novel alterations in protein structure or abundances with biomarker potential. We also identified a novel diagnostic biomarker of gastric cancer using a proteomic approach [6]. We are now investigating biomarkers of personalized therapies for gastric cancer in collaboration with other researchers in the United Kingdom.