Clinical endpoints in trials of chemoradiation for patients with anal cancer

This Review examines the reporting of endpoints in randomised controlled trials (RCTs) of radical chemoradiation for treatment of squamous cell carcinoma of the anus. The types, frequency, and definitions of clinical primary and secondary endpoints, and patient-reported outcome measures, reported in the methods and results sections of papers (and protocols, if available) were examined. Only six published RCTs comprising 2877 patients were identified. Primary outcome measures varied across the trials analysed: two used disease-free survival, one used progression-free survival, two used local failure, and one used colostomy-free survival. Secondary endpoints included overall survival, complete clinical response, quality of life, toxicity, and compliance. The definitions for primary and secondary endpoints were not consistent across trials, particularly for treatment failure (local, regional, and distant). We conclude that the quality of outcome reporting in RCTs of squamous cell carcinoma of the anus is inconsistent. A core set of outcomes, including clinical and patient-reported outcome measures with standardised definitions, is needed to improve the reporting of RCTs examining chemoradiation for treatment of patients with squamous cell carcinoma of the anus.