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 fenretinide for the prevention of contralateral breast cancer. Accrual screened 4,030 potentially eligible patients of whom 1,815 were randomized. Two strategies of recruitment were used, i.e. retrospective and prospective. In the retrospective accrual, the medical staff reviewed the records of breast cancer patients who had received curative surgery to select those who fulfilled the eligibility criteria of the study. For the prospective recruitment operated, patients were contacted after the beginning of the trial. The study started in March 1987 and accrual closed on July 31, 1993. The planned accrual period was extended by 19 months. The yearly accrual tended to decrease with time. This was mainly due to the end of the retrospective recruitment and to the introduction of adjuvant chemotherapy, a reason for exclusion 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.