The influence of traumatic lumbar puncture and timing of intrathecal therapy on outcome of pediatric acute lymphoblastic leukemia.

The CNS is a frequent site of relapse of childhood acute lymphoblastic leukemia (ALL). Traumatic lumbar puncture (TLP) is thought to increase the risk of CNS relapse. The authors examined whether TLP at the time of diagnosis affected outcome and whether this effect was influenced by the timing of intrathecal therapy (IT) in 77 patients with newly diagnosed ALL. IT was instilled at the time of either the diagnostic LP (early) or a second LP 24--48 h later (delayed). Of the 19 patients who had a TLP at diagnosis and received late IT therapy, 6 had isolated CNS relapse and 2 had combined CNS and bone marrow (BM) relapse. Of the 9 patients who had TLP and received early IT therapy, 1 had a CNS relapse (p=.20). In an analysis stratified according to risk of relapse, the odds ratio (OR) for relapse was 0.8 among patients at low and standard risk who had delayed IT therapy after TLP (p=.99) vs. 0.17 for those who had early IT (p=.47). Importantly, among patients with high-risk ALL, the OR for relapse was 21.0 for delayed IT therapy (p=.09) and only 1.5 for early IT therapy after TLP (p=.99). The results indicate that TLP at diagnosis appears to increase the risk of CNS relapse markedly in patients with high-risk ALL, and the use of early IT therapy appears to reduce this risk. These findings need to be confirmed by prospective, randomized studies.