Quality and consistency of phase III clinical trial abstracts presented at an Annual Meeting of the American Society of Clinical Oncology compared with their subsequent full-text publications

Abstract

6537 Background: Practice guidelines and evidence summaries in oncology are developed by experts to assist providers in making appropriate decisions regarding management. These documents result from a systematic review of literature from medical journals and meeting proceedings. Because there is often less rigorous peer reviewing of abstracts published in these proceedings compared to journal publications, the quality of evidence provided by these abstracts is uncertain. Methods: We identified abstracts describing phase III clinical trials of chemotherapy, chemoradiotherapy, immune therapy and hormone therapy presented at the 36th ASCO Annual Meeting in May 2000. We searched Medline and Pubmed for all corresponding publications. Data was extracted from the abstracts and publications meeting our inclusion criteria. Results: A total of 192 abstracts were identified. Seventy-four abstracts met our inclusion criteria. Six years after the 2000 ASCO Annual Meeting, 74% of these abstracts had corresponding publications. 39% of the abstracts explicitly indicated that they were reporting interim results. The primary endpoint was stated in 34% of the abstracts and 100% of the published papers. The primary outcome result differed by greater than five percent between the abstract and publication in 25% of the abstracts. The statistical significance of the primary outcome changed in 7% of the abstracts with publications. The final conclusion was consistent between the abstract and publication for 92% of the abstracts with reported conclusions. Conclusions: ASCO annual meeting abstracts of phase III trials appear to consistently reflect final published results and can likely be used in practice guidelines. However, occasional discrepancies underline the need for caution in completely adopting these results prior to full publication. No significant financial relationships to disclose.