One of the key factors to a cancer clinical trial’s success is the ability to enroll an adequate number of patients in an appropriate timeframe.

Identifying barriers to slow accrual and ways to address them can help researchers and nurse scientists make big steps in the fight against cancer in the era of the National Cancer Moonshot Initiative.

In a study published in Clinical Cancer Research, researchers analyzed 4,269 phase I–III clinical trials conducted at the University of Texas MD Anderson Cancer Center between 1981 and 2011. The trials enrolled a median of 16 patients and an average of 8.7 patients per trial. Eighteen percent of the trials were considered slow accruing, defined as enrolling fewer than two patients per year.

Researchers found that trials that were part of a national cooperative group, had a delay from activation to first enrollment, and had a higher maximum target accrual were more likely to be slow accruing. Phase II and III trials were slower accruing than phase I trials.

Steps that MD Anderson took to improve accrual included providing funding incentives for local investigators involved in national cooperative group trials and for underfunded trials that achieved successful accrual. The institution also required investigators in slow-accruing trials to improve accrual rates.