Time from diagnosis to relapse

In general, patients whose relapses occur earlier after initial diagnosis fare worse than those who experience later relapses.[15] For example, survival rates for patients with relapsed B-ALL range from less than 20% for patients with marrow relapses occurring within 18 months from diagnosis to higher than 60% for those whose relapses occur more than 36 months from diagnosis.[5,13,18]

For patients with isolated central nervous system (CNS) relapses, the overall survival (OS) rates are 40% to 50% for early relapse (<18 months from diagnosis) and 75% to 80% for those with late relapses (>18 months from diagnosis).[13,19] No evidence exists that early detection of relapse by frequent surveillance (complete blood counts or bone marrow tests) in off-therapy patients improves outcome.[20]