Reporting of Outcomes in Gastric Cancer Surgery Trials: A Systematic Review


Session type:

Bilal Alkhaffaf1,Iain Bruce1,Paula Williamson2,Jane Blazeby3,Anne-Marie Glenny4
1Central Manchester University Hospitals NHS Foundation Trust,2University of Liverpool,3University of Bristol,4University of Manchester



Inconsistent reporting of outcomes in trials impacts negatively on the ability to produce robust evidence-based recommendations for clinical practice. This review examines the degree of variation in the reporting of outcomes described by gastric cancer surgery trials.


Systematic literature searches were undertaken to identify randomised control trials (RCTs) published between 1996 and 2016 investigating therapeutic surgical interventions for gastric cancer. Outcomes were listed verbatim, categorized into groups (outcome domains) and examined for definitions and measurement instruments.


Of 2794 abstracts screened, 52 eligible publications from 32 trials (9,073 participants) were identified. A total of 756 outcomes were reported of which 660 (87 per cent) were undefined. No single outcome was reported by all trials. ‘Complications’ was the most frequently reported ‘outcome domain’ in which 252 unique terms were described. 12 trials (38 per cent) classified complications according to severity, with 5 (16 per cent) using a formal classification system (Clavien-Dindo or Accordion scale). A total of 33 unique terms were used to describe ‘mortality’ after surgery. Of 27 trials which described ‘short-term’ mortality, 17 (63 per cent) provided one of 5 definitions. Seven trials (22 per cent) described ‘patient-reported outcomes’ and 3 (9 per cent) measured ‘quality of life’ after surgery.


Reporting of outcomes in gastric cancer surgery trials is inconsistent and lacks methodological rigour. A consensus approach to develop a minimum set of well-defined, standardised outcomes to be used by all future trials examining therapeutic surgical interventions for gastric cancer is needed. This should take into account the views of all key stakeholders including patients. The GASTROS (GAstric cancer Surgery Trials Reported Outcomes Standardisation) study aims to address this problem.