The relationship between clinical trial accrual volume and outcomes in acute myeloid leukemia: A SWOG/ECOG-ACRIN study (S0106 and E1900).

Purpose: To study whether institutional clinical trial accrual volume affects clinical outcomes of younger (age less than 61 years) patients with acute myeloid leukemia.

Patients And Methods: We investigated the impact of clinical trial accrual on response rates, early mortality and survival in patients with AML enrolled between 2002 and 2009 into two parallel cooperative group clinical trials SWOG S0106/ECOG-ACRIN E1900. Institutions were classified as low- (LAIs) (≤ 9 enrolled patients) or high-accruing institutions (HAIs) (≥10 enrolled patients). Fisher's exact text and logistic regression analysis were used to analyze the response and early mortality rates. The effect of accrual volume on survival was analyzed by log-rank tests and Cox regression models.

Results: A total of 1252 patients from 152 institutions were included in the final analyses. The median clinical trial registrations in HAIs was 19 patients (range, 10 to 92) versus 3 (range, 1 to 9) patients in LAIs. In multivariate analyses, HAIs, as a quantitative covariate, was associated with improved complete remission rates (odds ratio (OR) 1.08, p = 0.0051), but no improvement median overall survival (HR 0.97, p = 0.065) or median event-free (hazard ratio (HR) 0.97, p = 0.05). Early mortality rates were similar between cohorts and academic affiliation had no impact on response rates or survival.

Conclusion: Clinical trial accrual volume, had an independent, albeit modest, impact on complete remission rates, but not on overall survival and event-free in younger patients with AML.