title: Ongoing problems concerning 7thTNM Staging System and Proposals for 8thTNM Staging System of Gastric Cancer.
abstract: Because of different prognosis of gastric cancer patients with the same T and N stages, the impossibility of N3 staging in patients with fewer than 15 removed lymph nodes, and the presence of stage migration phenomenon, the 6thedition TNM Staging System for gastric cancer was updated to the 7thedition TNM staging system in 2009. Despite some opposing views, the superiority of the 7thedition TNM staging system compared to the 6thhas been demonstrated in many studies. However, there are doubts about the 7thedition that it will reduce the stage migration phenomenon. The most important problem about the 7thTNM staging system is regarding subgroups N3a and N3b. The separation of N3 stage as N3a and N3b does not contribute to the TNM staging system. In conclusion, separate usage of N3a and N3b subgroups in the TNM staging system should be considered in the creation phase of the 8thedition.
authors.affiliation: Department of Surgery, Division A, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey.
authors.forename: Enver
authors.initials: E
authors.lastname: Ilhan
authors.affiliation: Department of Surgery, Division A, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey.
authors.forename: Orhan
authors.initials: O
authors.lastname: Ureyen
authors.affiliation: Department of Surgery, Izmir Military Hospital, Izmir, Turkey.
authors.forename: Ulvi Mehmet
authors.initials: UM
authors.lastname: Meral
keywords: N-ratio; N3a; N3b; TNM; gastric cancer