Background: Cancer is a major healthcare priority and the topic of large number of systematic reviews outside the Cochrane Library. Until the recent founding of the Cochrane Cancer Alliance, it has not been a focus area for Cochrane.
Objectives: We performed this study to assess the current scope and impact of the Cochrane Reviews related to cancer.
Methods: Based on a written protocol, systematically we identified all Cochrane Reviews in Archie published over a 10-year time period (March 2006 to March 2016) that pertained to cancer. Two reviewers independently applied predefined inclusion and exclusion criteria; discrepancies were settled by discussion and if necessary, third party arbitration. We excluded withdrawn, inactive and reviews at the protocol stage. We collected citation data using the Institute for Scientific Information Web of Science database. Analysis was performed on reviews that had a minimum follow-up period of 12 months. We performed descriptive statistics using SPSS Version 23.
Results: From a total of 10,021 titles, we identified 1198 titles pertaining to oncology. Of these, 565 were published Cochrane Reviews, and 507 had at least 12 months of follow-up data. The main contributors were the Gynecological, Neuro-oncology and Orphan Cancer Group (n = 124), the Colorectal Cancer Group (n = 66), and the Pain, Palliative and Supportive Care Group (n = 94). The overall median citation count was 6.0 (interquartile range (IQR) 2 to 18); 15.6% (79/507) of reviews had not been cited. Among review groups with at least 10 cancer-related reviews, the Pain, Palliative and Supportive Care, Urology, and Colorectal Groups had the highest median citation rates of 12 (IQR 2.5 to 24), 12 (IQR 5 to 30) and 11 (IQR 4 to 36), respectively.
Conclusions: Citation analyses provide valuable insights into ongoing Cochrane activities that may help guide future investments. Increased efforts at topic prioritization and review dissemination are necessary to improve the impact of cancer-related Cochrane Reviews.