The impact of the UKCCCR anal cancer trial (ACT1) on population-based treatment and survival for squamous cell cancer of the anus Authors:

Introduction: Between 1987 and 1994 three randomised phase III trials demonstrated that chemoradiotherapy with Mitomycin C and 5Fluorouracil was superior to radiotherapy alone (ACT1, EORTC) or radiotherapy with 5Fluorouracil (RTOG 87-04 ECOG 1289) for squamous cell carcinoma (SCC) of the anus. We explored the population-based changes in England before, during and after the UK-based ACT1 trial. Methods: Information was extracted from the National Cancer Data Repository on patients diagnosed with squamous cell anal cancer in England between 1981 and 2010 (n=11,743). Robust treatment information was available for the Yorkshire region (n=1,065). Changes in treatment patterns and three-year survival were investigated in seven-year cohorts prior to, during and after the ACT1 trial. Results: In Yorkshire, the proportion of patients receiving surgery alone fell from 61.6% prior to, 29.8% during and 12.5% after ACT1; the proportion of patients receiving primary chemoradiotherapy rose from 6.5% prior to, 17.7% during and 58.8% after ACT1 and continued to rise to 70.3% in the subsequent period. Three-year survival improved during the study period from 59.5% (95% CI 56.662.2) prior to ACT1 to 73.6% (95% CI 71.9-75.2) after the trial. Survival in Yorkshire was comparable to that in England. Conclusions: Treatment for SCC of the anus changed dramatically during the study period. The predominant use of surgery prior to ACT1, a transition phase during the trial and a dramatic increase in the use of chemoradiotherapy after ACT1 provides strong evidence of the impact of the trial on population-based practice. Survival has continued to increase during this period.