Comparison of international guidelines on the accompanying therapy for advanced gastric cancer: reasons for the differences.

The purpose of this study was to determine if international guidelines differ in their recommendations concerning additive therapy for advanced, but potentially curable, gastric cancer. A systematic search of the English and German literature was conducted in the databases Medline, Cochrane Database, Embase, and PubMed. The search terms used were 'guidelines gastric cancer,' 'guidelines stomach cancer,' and 'Leitlinien Magenkarzinom.' Six different guidelines published after January 1, 2010, in which the tumors were classified according to the seventh edition of the TNM system (2010), were identified. Although the examined guidelines were based on the same study results, their recommendations concerning accompanying therapy for gastric cancer differ considerably. While perioperative chemotherapy is recommended in Germany, Great Britain, and large parts of Europe, postoperative adjuvant radiochemotherapy or perioperative chemotherapy is recommended in the USA and Canada. In Japan, postoperative adjuvant chemotherapy is recommended.The results of identical studies were interpreted differently in different countries. Since considerable effort is required for each country to separately test relevant studies for their validity and suitability, an international cooperation could simplify the creation of a common basis for guidelines and contribute to improved comparability of international guidelines.