title: Postoperative adjuvant chemotherapy of gastric cancer: scrutiny into the clinical evidence based on quality assessment of medical literature of randomized controlled trials.
abstract: The aim of this study was to scrutinize the evidence of adjuvant chemotherapy of gastric cancer by assessing the quality of the medical literature of randomized controlled trials (RCTs). A quality assessment (QA) scoring system was devised with the three parameters-control of bias, quality of report, and quality of design-which consisted 19 items. We searched for all the publications of the RCTs, from 1969 to 2007, with surgery-only arm, and their associated meta-analyses to score. Among the 26 RCTs, quality of three articles were graded as (2+), 10 articles as (1+), and 13 articles as (-). Recently published studies had overall better quality of report, but not necessarily better quality of design. Three studies demonstrating a positive survival benefit of adjuvant chemotherapy had a grade (1+). Hierarchical clustering revealed that the 26 articles were grouped into three major branches associated with study quality and a multi-institutional setting. We also obtained a statistically significant set of ten items (P < 0.001) that could differentiate articles of good (1-2+) and low quality (-) through supervised two-way hierarchical clustering. Finally, the level of recommendation for adjuvant chemotherapy in gastric cancer was to be a "B" according to the Scottish Intercollegiate Guidelines Network (SIGN) System. QA of medical literature should be an essential consideration for medical-related decision-making and the formation of evidence-based guidelines. Multidisciplinary discussion to develop and refine trial design is important for procuring better quality of RCTs of adjuvant chemotherapy of gastric cancer.
authors: Cancer Metastasis Research Center, Yonsei Cancer Center, Yonsei University College of Medicine, 250 Seongsanno (134 Shinchon-Dong), Seodaemun-Gu, Seoul, 120-752, South Korea.
authors: Hei-Cheul
authors: HC
authors: Jeung
authors: Sun Young
authors: SY
authors: Rha
authors: Sang Joon
authors: SJ
authors: Shin
authors: Joong Bae
authors: JB
authors: Ahn
authors: Jae Kyung
authors: JK
authors: Roh
authors: Chan Hee
authors: CH
authors: Park
authors: Sung Hoon
authors: SH
authors: Noh
authors: Hyun Cheol
authors: HC
authors: Chung
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D016208:Databases, Factual; D019317:Evidence-Based Medicine; D006801:Humans; D011184:Postoperative Period; D011785:Quality Assurance, Health Care; D016032:Randomized Controlled Trials as Topic; D013274:Stomach Neoplasms / Q000188:drug therapy*