The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Cellular Classification and Prognostic Variables ¹

Added text ² about chromosomal translocations that have been identified in T-cell ALL which result in the aberrant expression of transcription factors. High expression of transcription factor TLX1/HOX11 occurs in 5% to 10% of pediatric T-cell ALL patients and is associated with a more favorable outcome. Overexpression of TLX3/HOX11L2 occurs in approximately 20% of pediatric T-cell ALL patients and appears to be associated with increased risk of treatment failure. NOTCH1 mutations occur in approximately 50% of T-cell ALL cases, but the prognostic significance is unclear (cited Schneider et al. as reference 57, Armstrong et al. as reference 58, Bergeron et al. as reference 59, van Grotel et al. as reference 60, Cavé et al. as reference 61, Baak et al. as reference 62, Ferrando et al. as reference 63, Kees et al. as reference 64, Ballerini et al. as reference 65, Weng et al. as reference 66, Breit et al. as reference 67, and Zhu et al. as reference 68).

Untreated Childhood Acute Lymphoblastic Leukemia ³

Added Waber et al. as reference 56 ⁴. Included a level of evidence ranking [Level of evidence: 1iiC].

Childhood Acute Lymphoblastic Leukemia in Remission ⁵

Added Seibel et al. as reference 24 ⁶. Included a level of evidence ranking [Level of evidence: 1iiA].

Recurrent Childhood Acute Lymphoblastic Leukemia ⁷

Added Malempati et al. as reference 5 ⁸. Included a level of evidence ranking [Level of evidence: 3iiDi].

Added text ⁹ to state that in the majority of children with isolated extramedullary relapses, submicroscopic marrow disease can be demonstrated using sensitive molecular techniques, and successful treatment strategies must effectively control both local and systemic disease. The level of submicroscopic marrow involvement may also predict response to post-relapse therapy (cited Hagedorn et al. as reference 53).

Added text ¹⁰ about clinical trials that are currently testing the use of chemotherapy that may be able to achieve antileukemia levels in the testes (cited van den Berg et al. as reference 60).