Some clinical trial groups have approached CNS2 and traumatic lumbar puncture by utilizing more intensive therapy, primarily additional doses of intrathecal therapy during induction.[37,44]; [Level of evidence: 2A] Other groups have not altered therapy based on CNS2 status.[38,45]
To determine whether a patient with a traumatic lumbar puncture (with blasts) should be treated as CNS3, the COG uses an algorithm relating the WBC and red blood cell counts in the spinal fluid and the peripheral blood.
Testicular involvement at diagnosis
Overt testicular involvement at the time of diagnosis occurs in approximately 2% of males, most commonly in T-cell ALL.
In early ALL trials, testicular involvement at diagnosis was an adverse prognostic factor. With more aggressive initial therapy, however, it does not appear that testicular involvement at diagnosis has prognostic significance.[47,48] For example, the European Organization for Research and Treatment of Cancer (EORTC [EORTC-58881]) reported no adverse prognostic significance for overt testicular involvement at diagnosis.
The role of radiation therapy for testicular involvement is unclear. A study from St. Jude Children's Research Hospital (SJCRH) suggests that a good outcome can be achieved with aggressive conventional chemotherapy without radiation. The COG has also adopted this strategy for boys with testicular involvement that resolves completely by the end of induction therapy. The COG considers patients with testicular involvement to be high risk regardless of other presenting features, but most other large clinical trial groups in the United States and Europe do not consider testicular disease to be a high-risk feature.
Down syndrome (trisomy 21)
Outcome in children with Down syndrome and ALL has generally been reported as somewhat inferior to outcomes observed in children who do not have Down syndrome.[49,50,51,52]
The lower EFS and OS of children with Down syndrome appear to be related to higher rates of treatment-related mortality and the absence of favorable biological features such as ETV6-RUNX1 or trisomies of chromosomes 4 and 10.[49,50,51,52,53] In a report from the COG, among B-precursor ALL patients who lacked MLL translocations, BCR-ABL1, ETV6-RUNX1, or trisomies of chromosomes 4 and 10, the EFS and OS were similar in children with and without Down syndrome. Certain genomic abnormalities, such as IKZF1 deletions, CRLF2 aberrations, and JAK mutations are seen more frequently in ALL arising in children with Down syndrome than in those without Down syndrome.[54,55,56,57,58] In one study of Down syndrome children with ALL, the presence of IKZF1 deletions (but not CRLF2 aberrations or JAK mutations) was associated with an inferior prognosis.