Characteristics of Asian 4 countries on cancer clinical trials registered in the International Clinical Trials Registry Platform between 2005 and 2018

BACKGROUND

The characteristics and comparison of countries regarding clinical trials for cancer were unknown. The World Health Organization-International Clinical Trials Registry Platform (WHO-ICTRP) are providing data from various countries and releases them generally in a downloadable format. We aimed to examine and descriptively identify the number of cancer clinical trials registered in the world and the fundamental characteristics in Asian 4 countries of China, India, Japan and South Korea, focusing on study characteristics, e.g., phase or targeted size, using the WHO-ICTRP.

METHODS

We extracted information on cancer clinical studies in the ICTRP database on September 20, 2019. Then, we performed a cross-sectional study on the annual number of registered studies and country, registered registry, phase, target sizes and sponsors.

RESULTS

We identified 80,677 cancer clinical studies. The annual number of registered cancer clinical studies significantly increased between 2005 and 2018 (3,172 to 8,156, β =382.2, 95% CI: 329.6, 434.8). Among the Asian 4 countries, the numbers of trials were significantly increasing in 2005-2018 (P<0.001). The characteristics on interventional studies for cancer differed in those 4 countries, e.g., the registered registries, phase and sponsors, compared with the US.

CONCLUSIONS

This study descriptively clarified an increase and the characteristics of cancer clinical trials in Asian 4 countries. It suggests to take that characteristics into account and select a database or data source discreetly for analysis of clinical trials, according to the purpose of the research and the required data.

Clinical trial registry use in minimally invasive surgical oncology systematic reviews and meta-analyses

Publication bias can arise in systematic reviews when unpublished data are omitted and lead to inaccurate clinical decision making and adverse clinical outcomes. By conducting searches of clinical trial registries (CTRs), researchers can create more accurate systematic reviews and mitigate the risk of publication bias. The aims of this study are: to evaluate CTR use in systematic reviews and meta-analyses within the minimally invasive surgical oncology (MISO) literature; to conduct a search of ClinicalTrials.gov for a subset of reviews to determine if eligible trials exist that could have been used. This is a cross-sectional study of 197 systematic reviews and meta-analyses retrieved from PubMed. Of 137 included studies, 18 (13.1%) reported searching a CTR. Our ClinicalTrials.gov search revealed that of the 25 randomly selected systematic reviews that failed to conduct a trial registry search, 16 (64.0%) would have identified additional data sources. MISO systematic reviews and meta-analyses do not regularly use CTRs in their data collection, despite eligible trials being freely available.