Background: The American Society of Clinical Oncology Annual Meeting is the largest forum for presentation of clinical research in oncology. We quantified the contribution of countries and assessed correlates of their presence at such meetings.
Methods: After stratifying abstracts according to category of presentation (oral, poster, and 'publication only'), we took a random sample of 10% of the studies presented at years 2001-2003 and 2006-2008. We assigned abstract nationality using the affiliation of authors. For multinational studies, we developed an algorithm to assign nationality.
Results: Of the 22 045 eligible abstracts, 2206 were analyzed and represented 71 countries: 905 (41%) abstracts were from a single institution, 969 (44%) were multicenter, uninational studies, and 332 (15%) were multinational studies. United States nationality was assigned to 49% of all abstracts and the next 14 countries with a higher number of studies accounted for 41%. There was a statistically significant temporal trend in the proportion of multinational studies. Also, multinational studies and abstracts with United States nationality were more frequently presented in oral and poster fashion and had more frequent involvement of the pharmaceutical industry.
Conclusion: This study provides a geographic overview of clinical cancer research and indicates that multinational collaboration is increasing.