Accrual issues for chemoprevention trials: The example of the 4-HPR study for the prevention of contralateral breast cancer

This paper describes the accrual of the controlled clinical trial with fenr etinide for the prevention of contralateral breast cancer. Accrual screened 4,030 potentially eligible patients of whom 1,815 were randomized. Two str ategies of recruitment were used, i.e. retrospective and prospective. In th e retrospective accrual, the medical staff reviewed the records of breast c ancer patients who had received curative surgery to select those who fulfil led the eligibility criteria of the study. For the prospective recruitment operated, patients were contacted after the beginning of the trial. The stu dy started in March 1987 and accrual closed on July 31, 1993. The planned a ccrual period was extended by 19 months. The yearly accrual tended to decre ase with time. This was mainly due to the end of the retrospective recruitm ent and to the introduction of adjuvant chemotherapy, a reason for exclusio n from the trial, also for patients with negative axillary nodes. The known accrual difficulties of chemoprevention studies proved also to be true for the high-risk population of this trial.