Relapse in teenage and young adult patients treated on a paediatric minimal residual disease stratified ALL treatment protocol is associated with a poor outcome: results from UKALL2003

Outcomes for teenage and young adult (TYA) patients with acute lymphoblastic leukaemia (ALL) who relapse on contemporary risk‐adapted paediatric protocols are largely unknown and there is no consensus on optimal salvage strategies. We assessed the treatment and outcome of TYA patients (aged 16–24 years) recruited to the UKALL2003 trial, who relapsed following attainment of complete morphological remission. Forty‐two of 223 patients (18·8%) relapsed, the majority (n = 26, 62%) on treatment. Thirty‐eight (90%) patients received salvage treatment, with 22 (58%) achieving second remission (CR2) and 21 patients receiving an allogeneic haematopoietic cell transplant (alloHSCT). Post‐relapse outcomes were poor with a 5‐year overall survival (OS) of 23% (95% confidence interval; 11–37%). Outcomes for patients relapsing on active treatment were inferior to those relapsing after completing treatment (5‐year OS 9% vs. 52%, log‐rank P = 0·001). No patient with B cell ALL relapsing on treatment was alive at the end of the study period. TYA patients with ALL who relapse on the UK paediatric protocol, UKALL2003, are largely unsalvageable with conventional approaches aimed at achieving CR2 followed by alloHSCT. Future efforts should be aimed at identifying those patients who are destined to relapse and exploring novel treatment approaches for this high‐risk group and for those who do relapse.     

Survival of childhood acute lymphoid leukaemia in Yorkshire by clinical trial era, 1990–2011

Gender‐specific differences in survival by clinical trial era in Yorkshire were assessed for children with acute lymphoid leukaemia (ALL) enrolled onto UKALLXI, ALL97/99 or UKALL2003 (n = 630; 1990–2011). For males, there was a non‐significant improvement in survival for ALL97/99 [hazard ratio (HR) = 0·77; 95% confidence interval (CI) 0·43–1·42) and a significant improvement for UKALL2003 (HR = 0·50; 95%CI 0·25–0·99) compared to UKALLXI. For females, survival was significantly improved for ALL97/99 (HR = 0·33; 95%CI 0·14–0·78), and non‐significantly improved for UKALL2003 (HR = 0·51; 95%CI 0·25–1·08) compared to UKALLXI. Modest overall survival improvements masked clinically important gender‐specific changes over time by trial era, requiring confirmation in larger population‐based studies.     

Outcome for children and young people with Early T‐cell precursor acute lymphoblastic leukaemia treated on a contemporary protocol,UKALL 2003

We investigated the outcome for children and young people with Early T‐precursor acute lymphoblastic leukaemia (ETP‐ALL), a recently described poor prognosis sub‐group of T‐ALL, treated on a contemporary protocol, UKALL 2003. After a median follow‐up of 4 years and 10 months, the ETP sub‐group, representing 16% of T‐ALL patients, had non‐significantly inferior 5‐year event‐free survival (76·7% vs. 84·6%, P = 0·2) and overall survival (82·4% vs. 90·9%, P = 0·1), and a higher relapse rate (18·6% vs. 9·6%, P = 0·1) compared to typical T‐ALL. ETP‐ALL has an intermediate risk outcome, which does not warrant experimental treatment or first remission allogeneic transplant for the group universally.     

Clinical utility of next‐generation sequencing‐based minimal residual disease in paediatric B‐cell acute lymphoblastic leukaemia

We assessed the clinical utility of next‐generation sequencing (NGS)‐based monitoring of minimal residual disease (MRD) in a uniformly treated cohort of 79 patients with paediatric B‐cell acute lymphoblastic leukaemia. Bone marrow samples were collected at the time of diagnosis, days 33 and 80, pre‐ (4–5 months) and post‐ (24 months) maintenance therapy time points, and at relapse. We identified leukaemia‐specific CDR3 sequences in 72 of 79 patients (91%) and detected MRD in 59 of 232 samples. Although MRD was detected in 28 of 55 samples (51%) on day 33, the frequencies of MRD detection decreased to 25% (16/65) at day 80, 19% (11/58) at 4–5 months and 7·4% (4/54) at 24 months. In a univariate analysis, positive MRD results on day 80 [relative risk (RR) 95% confidence interval (CI) = 7·438 (2·561–21·6), P < 0·001], at 4–5 months [RR (95% CI) = 10·24 (3·374–31·06), P < 0·001], and at 24 months [RR (95% CI) = 19·26 (4·974–74·59), P < 0·001] exhibited statistically significant associations with inferior leukaemia‐free survival; this was confirmed using a Cox proportional hazard model. Our study suggests the promising potential of NGS‐MRD for patients with B‐cell ALL.     

Outcome of Down syndrome associated acute lymphoblastic leukaemia treated on a contemporary protocol

We report the outcome for children and young people with Down syndrome‐associated acute lymphoblastic leukaemia (DS‐ALL) treated on a contemporary protocol. Compared with non‐DS ALL, patients with DS‐ALL had an inferior event‐free survival (65·6% vs. 87·7% at 5 years; P < 0·00005) and overall survival (70·0% vs. 92·2%; P < 0·00005). Excess treatment‐related mortality – was primarily responsible for the worse outcomes for DS‐ALL (21·6% at 5 years, vs. 3·3%, P < 0·00005). Minimal residual disease (MRD) risk status was highly discriminant for relapse in DS patients with 0/28 relapses in the MRD low risk group.     

Implications of delayed bone marrow aspirations at the end of treatment induction for risk stratification and outcome in children with acute lymphoblastic leukaemia

Minimal residual disease (MRD) at the end of induction therapy is important for risk stratification of acute lymphoblastic leukaemia (ALL), but bone marrow (BM) aspiration is often postponed or must be repeated to fulfil qualitative and quantitative criteria for morphological assessment of haematological remission and/or MRD analysis. The impact of BM aspiration delay on measured MRD levels and resulting risk stratification is currently unknown. We analysed paired MRD data of 289 paediatric ALL patients requiring a repeat BM aspiration. MRD levels differed in 108 patients (37%) with a decrease in the majority (85/108). This would have resulted in different risk group allocation in 64 of 289 patients (23%) when applying the ALL‐Berlin‐Frankfurt‐Münster 2000 criteria. MRD change was associated with the duration of delay; 40% of patients with delay ≥7 days had a shift to lower MRD levels compared to only 18% after a shorter delay. Patients MRD‐positive at the original but MRD‐negative at the repeat BM aspiration (n = 50) had a worse 5‐year event‐free survival than those already negative at first aspiration (n = 115) (86 ± 5% vs. 94 ± 2%; P = 0·024). We conclude that BM aspirations should be pursued as scheduled in the protocol because delayed MRD sampling at end of induction may result in false‐low MRD load and distort MRD‐based risk assessment.     

Treatment outcome of young children with acute lymphoblastic leukaemia: achievements and directions implied from Shanghai Children's Medical Centre based SCMC‐ALL‐2005 protocol

This multicenter study used the Shanghai Children's Medical Center (SCMC)‐ALL‐2005 protocol for treatment of young patients (<2 years old) with acute lymphoblastic leukaemia (ALL), which was designed to improve treatment outcome in Chinese paediatric patients. These aims were pursued through risk‐directed stratification based on presenting clinical and genetic features, minimal residual disease (MRD) levels and treatment response. All the patients achieved completed remission with 5‐year event‐free survivals of 82·6 ± 9·7% (low risk), 52·6 ± 8·4% (intermediate risk), 28·6 ± 17·1% (high risk). Disease recurrence was detected in bone marrow, bone marrow plus testis, testis alone and central nervous system in 16 (24·2%), 1 (1·5%), 1 (1·5%) and 1 (1·5%) patients respectively. No deaths were reported during induction. The SCMC‐ALL‐2005 trial for ALL patients <2 years old indicated high remission induction and low infection and treatment‐related mortality rates.     

NOTCH1 mutations are associated with favourable long‐term prognosis in paediatric T‐cell acute lymphoblastic leukaemia: a retrospective study of patients treated on BCH‐2003 and CCLG‐2008 protocol in China

Activating mutations of NOTCH1 are a common occurrence in T‐cell acute lymphoblastic leukaemia (T‐ALL), but its impact on T‐ALL treatment is still controversial. In this study, the incidence, clinical features, and prognosis of 92 Chinese children with T‐ALL treated using the Beijing Children's Hospital‐2003 and Chinese Childhood Leukaemia Group‐2008 protocols were analysed. NOTCH1 mutations were found in 42% of T‐ALL patients and were not associated with clinical features, prednisone response, and minimal residual disease (MRD) at day 33 and 78. However, proline, glutamate, serine, threonine (PEST)/transactivation domain (TAD) mutations were associated with younger age (15/16 mutant vs. 48/76 wild‐type, P = 0·018) and more central nervous system involvement (4/16 mutant vs. 3/76 wild‐type, P = 0·016); while heterodimerization domain (HD) mutations were associated with KMT2A‐MLLT1 (MLL‐ENL; 4/30 mutant vs. 1/62 wild‐type, P = 0·037). Furthermore, prognosis was better in patients with NOTCH1 mutations than in those with wild‐type NOTCH1 (5‐year event‐free survival [EFS] 92·0 ± 4·5% vs. 64·0 ± 7·1%; P = 0·003). Long‐term outcome was better in patients carrying HD mutations than in patients with wild‐type HD (5‐year EFS 89·7 ± 5·6% vs. 69·3 ± 6·2%; P = 0·034). NOTCH1 mutations and MRD at day 78 were independent prognostic factors. These findings indicate that NOTCH1 mutation predicts a favourable outcome in Chinese paediatric patients with T‐ALL on the BCH‐2003 and CCLG‐2008 protocols, and may be considered a prognostic stratification factor.     

Thiopurine methyltransferase and treatment outcome in the UK acute lymphoblastic leukaemia trial ALL2003

The influence of thiopurine methyltransferase (TPMT) genotype on treatment outcome was investigated in the United Kingdom childhood acute lymphoblastic leukaemia trial ALL2003, a trial in which treatment intensity was adjusted based on minimal residual disease (MRD). TPMT genotype was measured in 2387 patients (76% of trial entrants): 2190 were homozygous wild‐type, 189 were heterozygous for low activity TPMT alleles (166 TPMT*1/*3A, 19 TPMT*1/*3C, 3 TPMT*1/*2 and 1 TPMT*1/*9) and 8 were TPMT deficient. In contrast to the preceding trial ALL97, there was no difference in event‐free survival (EFS) between the TPMT genotypes. The 5‐year EFS for heterozygous TPMT*1/*3A patients was the same in both trials (88%), but for the homozygous wild‐type TPMT*1/*1 patients, EFS improved from 80% in ALL97% to 88% in ALL2003. Importantly, the unexplained worse outcome for heterozygous TPMT*1/*3C patients observed in ALL97 (5‐year EFS 53%) was not seen in ALL2003 (5‐year EFS 94%). In a multivariate Cox regression analysis the only significant factor affecting EFS was MRD status (hazard ratio for high‐risk MRD patients 4·22, 95% confidence interval 2·97–5·99, P < 0·0001). In conclusion, refinements in risk stratification and treatment have reduced the influence of TPMT genotype on treatment outcome in a contemporary protocol.     

Low burden of minimal residual disease prior to transplantation in children with very high risk acute lymphoblastic leukaemia: The NOPHO ALL2008 experience

The population-based Nordic/Baltic acute lymphoblastic leukaemia (ALL) Nordic Society for Paediatric Haematology and Oncology (NOPHO) ALL2008 protocol combined minimal residual disease (MRD)-driven treatment stratification with very intense first line chemotherapy for patients with high risk ALL. Patients with MRD ≥5% at end of induction or ≥10⁻³ at end of consolidation or following two high risk blocks were eligible for haematopoietic cell transplantation (HCT) in first remission. After at least three high risk blocks a total of 71 children received HCT, of which 46 had MRD ≥5% at end of induction. Ten patients stratified to HCT were not transplanted; 12 received HCT without protocol indication. Among 69 patients with evaluable pre-HCT MRD results, 22 were MRD-positive, one with MRD ≥10⁻³. After a median follow-up of 5·5 years, the cumulative incidence of relapse was 23·5% (95% confidence interval [CI]: 10·5–47·7) for MRD-positive versus 5·1% (95% CI: 1·3–19·2), P = 0·02) for MRD-negative patients. MRD was the only variable significantly associated with relapse (hazard ratio 9·1, 95% CI: 1·6–51·0, P = 0·012). Non-relapse mortality did not differ between the two groups, resulting in disease-free survival of 85·6% (95% CI: 75·4–97·2) and 67·4% (95% CI: 50·2–90·5), respectively. In conclusion, NOPHO block treatment efficiently reduced residual leukaemia which, combined with modern transplant procedures, provided high survival rates, also among pre-HCT MRD-positive patients.     

Minimal residual disease assessed by multi‐parameter flow cytometry is highly prognostic in adult patients with acute lymphoblastic leukaemia

The prognostic value of minimal residual disease (MRD) assessed by multi‐parameter flow cytometry (MFC) was investigated among 340 adult patients with B‐cell acute lymphoblastic leukaemia (B‐ALL) treated between 2004 and 2014 using regimens including the hyperCVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone, methotrexate, cytarabine) backbone. Among them, 323 (95%) achieved complete remission (CR) and were included in this study. Median age was 52 years (range, 15–84). Median white blood cell count (WBC) was 9·35 × 10⁹/l (range, 0·4–658·1 ×1 0⁹/l). MRD by MFC was initially assessed with a sensitivity of 0·01%, using a 15‐marker, 4‐colour panel and subsequently a 6‐colour panel on bone marrow specimens obtained at CR achievement and at approximately 3 month intervals thereafter. MRD negative status at CR was associated with improved disease‐free survival (DFS) and overall survival (OS) (P = 0·004 and P = 0·03, respectively). Similarly, achieving MRD negative status at approximately 3 and 6 months was associated with improved DFS (P = 0·004 and P < 0·0001, respectively) and OS (P = 0·004 and P < 0·0001, respectively). Multivariate analysis including age, WBC at presentation, cytogenetics (standard versus high risk) and MRD status at CR, 3 and 6 months, indicated that MRD negative status at CR was an independent predictor of DFS (P < 0·05). Achievement of an MRD negative state assessed by MFC is an important predictor of DFS and OS in adult patients with ALL.     

Bortezomib reinduction chemotherapy in high-risk ALL in first relapse: a report from the Children's Oncology Group

While survival in paediatric acute lymphoblastic leukaemia (ALL) is excellent, survival following relapse is poor. Previous studies suggest proteasome inhibition with chemotherapy improves relapse ALL response rates. This phase 2 Children's Oncology Group study tested the hypothesis that adding the proteasome inhibitor bortezomib to chemotherapy increases complete response rates (CR2). Evaluable patients (n = 135, 103 B-ALL, 22 T-ALL, 10 T-lymphoblastic lymphoma) were treated with reinduction chemotherapy plus bortezomib. Overall CR2 rates were 68 ± 5% for precursor B-ALL patients (<21 years of age), 63 ± 7% for very early relapse (<18 months from diagnosis) and 72 ± 6% for early relapse (18–36 months from diagnosis). Relapsed T-ALL patients had an encouraging CR2 rate of 68 ± 10%. End of induction minimal residual disease (MRD) significantly predicted survival. MRD negative (MRDneg; MRD <0·01%) rates increased from 29% (post-cycle 1) to 64% following cycle 3. Very early relapse, end-of-induction MRDneg precursor B-ALL patients had 70 ± 14% 3-year event-free (EFS) and overall survival (OS) rates, vs. 3-year EFS/OS of 0–3% (P = 0·0001) for MRDpos (MRD ≥0·01) patients. Early relapse patients had similar outcomes (MRDneg 3-year EFS/OS 58–65% vs. MRDpos 10–19%, EFS P = 0·0014). These data suggest that adding bortezomib to chemotherapy in certain ALL subgroups, such as T-cell ALL, is worthy of further investigation. This study is registered at http://www.clinical.trials.gov as NCT00873093.     

The inferior prognosis of adolescents with acute lymphoblastic leukaemia (ALL) is caused by a higher rate of treatment‐related mortality and not an increased relapse rate – a population‐based analysis of 25 years of the Austrian ALL‐BFM (Berlin‐Frankfurt‐Münster) Study Group

Adolescents aged 15–18 years with acute lymphoblastic leukaemia (ALL) have been historically reported to have a poorer prognosis than younger children. We retrospectively analysed the characteristics and outcome of 67 adolescents included in a population‐based series of 1125 non‐infant cases that were enrolled into four Austrian ALL‐BFM (Berlin‐Frankfurt‐Münster) multicentre trials at paediatric institutions within a 25‐year period. Five‐year event‐free survival (EFS) and overall survival (OS) were 66 ± 6% and 76 ± 5% respectively, and thus lower than in younger children (83 ± 1%, 91 ± 1%; P < 0·001). This was not due to an increased cumulative incidence of relapse (CIR) (5‐year CIR: 19 ± 5% vs. 13 ± 1%; P = 0·284), but due to an increased incidence of treatment‐related death [5‐year cumulative incidence of death (CID): 15 ± 4% vs. 3 ± 0%; P < 0·001] as a first event. Furthermore, while 44/67 (66%) non‐high‐risk adolescents had favourable 5‐year EFS and OS rates (76 ± 7%, 89 ± 5%), 18/67 (27%) high‐risk adolescents had an inferior outcome (5‐year EFS: 56 ± 12%, OS 61 ± 11%, P < 0·05). Among the latter patients the CID was significantly higher than in younger high‐risk children (22 ± 10% vs. 6 ± 2%; P = 0·020). Given that adolescent age is an independent risk factor for death as a first event, this specific age group may need particular vigilance when receiving intense BFM‐type chemotherapy, as relapse‐free survival is similar to younger children.     

The combination of bortezomib with chemotherapy to treat relapsed/refractory acute lymphoblastic leukaemia of childhood

Achieving complete remission (CR ) in childhood relapsed/refractory acute lymphoblastic leukaemia (ALL ) is a difficult task. Bortezomib, a proteasome inhibitor, has in vitro activity against ALL blasts. A phase I‐II trial, reported by the Therapeutic Advances in Childhood Leukaemia and Lymphoma (TACL ) consortium, demonstrated that bortezomib with chemotherapy has acceptable toxicity and remarkable activity in patients with relapsed ALL failing 2–3 previous regimens. We evaluated bortezomib in combination with chemotherapy in 30 and 7 children with B‐cell precursor (BCP ) and T‐cell ALL , respectively. Bortezomib (1·3 mg/m²/dose) was administered intravenously on days 1, 4, 8, and 11. Chemotherapy agents were the same as those used in the TACL trial, consisting of dexamethasone, doxorubicin, vincristine and pegylated asparaginase. Three patients (8·1%) died due to infections. Twenty‐seven patients (72·9%) achieved CR or CR with incomplete platelet recovery (CR p). Fourteen had minimal residual disease (MRD ) lower than 0·1%. Twenty‐two of 30 BCP ‐ALL patients (73·3%) and 5/7 patients (71%) with T‐cell ALL achieved CR /CR p. The 2‐year overall survival (OS ) is 31·3%; CR /CR p patients with an MRD response had a remarkable 2‐year OS of 68·4%. These data confirm that the combination of bortezomib with chemotherapy is a suitable/effective option for childhood relapsed/refractory ALL .     

A phase 1 trial of temsirolimus and intensive re‐induction chemotherapy for 2nd or greater relapse of acute lymphoblastic leukaemia: a Children's Oncology Group study (ADVL1114)

The phosphatidylinositol 3‐kinase (PI 3K)/mammalian (or mechanistic) target of rapamycin (mTOR ) signalling pathway is commonly dysregulated in acute lymphoblastic leukaemia (ALL ). A phase 1 trial of the mTOR inhibitor temsirolimus in combination with UKALL R3 re‐induction chemotherapy was conducted in children and adolescents with second or greater relapse of ALL . The initial temsirolimus dose level (DL 1) was 10 mg/m² weekly × 3 doses. Subsequent patient cohorts received temsirolimus 7·5 mg/m² weekly × 3 doses (DL 0) or, secondary to toxicity, 7·5 mg/m² weekly × 2 doses (DL ‐1). Sixteen patients were enrolled, 15 were evaluable for toxicity. Dose‐limiting toxicity (DLT ) occurred at all three dose levels and included hypertriglyceridaemia, mucositis, ulceration, hypertension with reversible posterior leucoencephalopathy, elevated gamma‐glutamyltransferase or alkaline phosphatase and sepsis. The addition of temsirolimus to UKALL R3 re‐induction therapy resulted in excessive toxicity and was not tolerable in children with relapsed ALL . However, this regimen induced remission in seven of fifteen patients. Three patients had minimal residual disease levels <0·01%. Inhibition of PI 3K signalling was detected in patients treated at all dose levels of temsirolimus, but inhibition at an early time point did not appear to correlate with clinical responses at the end of re‐induction therapy.     

No impact of high‐dose cytarabine and asparaginase as early intensification with intermediate‐risk paediatric acute lymphoblastic leukaemia: results of randomized trial TCCSG study L99‐15

The Tokyo Children's Cancer Study Group conducted a randomized controlled study to evaluate the effect of experimental early intensification using high‐dose cytarabine and L‐asparaginase in paediatric intermediate‐risk (IR) acute lymphoblastic leukaemia (ALL). A total of 310 IR ALL patients were randomized to receive either experimental early intensification (n = 156) or standard early intensification including standard‐dose cytarabine arm (n = 154) after induction therapy. The experimental arm consisted of high‐dose cytarabine and L‐asparaginase, while the standard arm consisted of standard‐dose cytarabine, oral 6‐mercaptopurine and cyclophosphamide. The probabilities of event‐free survival at 8 years in the experimental and standard arms were 72·3 ± 3·7% and 77·5 ± 3·5%, respectively (P = 0·32). The 8‐year overall survival rates for these two arms were 85·0 ± 3·0% and 86·9 ± 2·8%, respectively (P = 0·72). The frequency of infectious events was significantly higher in the experimental arm (66·4%) than in the standard arm (24·6%) (P < 0·001). In conclusion, experimental early intensification including high‐dose cytarabine followed by L‐asparaginase had no advantage over standard early intensification in paediatric IR ALL patients.     

Adjuvant tyrosine kinase inhibitor therapy improves outcome for children and adolescents with acute lymphoblastic leukaemia who have an ABL-class fusion

Patients with an ABL-class fusion have a high risk of relapse on standard chemotherapy but are sensitive to tyrosine kinase inhibitors (TKI). In UKALL2011, we screened patients with post-induction MRD ≥1% and positive patients (12%) received adjuvant TKI. As the intervention started during UKALL2011, not all eligible patients were screened prospectively. Retrospective screening of eligible patients allowed the outcome of equivalent ABL-class patients who did and did not receive a TKI in first remission to be compared. ABL-class patients who received a TKI in first remission had a reduced risk of relapse/refractory disease: 0% vs. 63% at four years (P = 0·009).     

Persistent MRD before and after allogeneic BMT predicts relapse in children with acute lymphoblastic leukaemia

Minimal residual disease (MRD) during early chemotherapy is a powerful predictor of relapse in acute lymphoblastic leukaemia (ALL) and is used in children to determine eligibility for allogeneic haematopoietic stem cell transplantation (HSCT) in first (CR1) or later complete remission (CR2/CR3). Variables affecting HSCT outcome were analysed in 81 children from the ANZCHOG ALL8 trial. The major cause of treatment failure was relapse, with a cumulative incidence of relapse at 5 years (CIR) of 32% and treatment‐related mortality of 8%. Leukaemia‐free survival (LFS) and overall survival (OS) were similar for HSCT in CR1 (LFS 62%, OS 83%, n = 41) or CR2/CR3 (LFS 60%, OS 72%, n = 40). Patients achieving bone marrow MRD negativity pre‐HSCT had better outcomes (LFS 83%, OS 92%) than those with persistent MRD pre‐HSCT (LFS 41%, OS 64%, P < 0·0001) or post‐HSCT (LFS 35%, OS 55%, P < 0·0001). Patients with B‐other ALL had more relapses (CIR 50%, LFS 41%) than T‐ALL and the main precursor‐B subtypes including BCR‐ABL1, KMT2A (MLL), ETV6‐RUNX1 (TEL‐AML1) and hyperdiploidy >50. A Cox multivariate regression model for LFS retained both B‐other ALL subtype (hazard ratio 4·1, P = 0·0062) and MRD persistence post‐HSCT (hazard ratio 3·9, P = 0·0070) as independent adverse prognostic variables. Persistent MRD could be used to direct post‐HSCT therapy.     

Incidence and risk factors for Central Nervous System thrombosis in paediatric acute lymphoblastic leukaemia during intensive asparaginase treatment: a single‐centre cohort study

Central Nervous System (CNS) thrombosis is a complication of acute lymphoblastic leukaemia (ALL) treatment that is potentially associated with significant morbidity and neurological sequelae. Its presumably multifactorial aetiology is poorly characterized. We conducted a single‐centre, retrospective cohort study on 346 ALL paediatric patients (1–16 years old) treated with asparaginase intensive Dana Farber Cancer Institute (DFCI) protocols from 1998 to 2011. The incidence, risk factors and outcome of CNS thrombosis were evaluated. CNS thrombosis occurred in 3·8% (13/346) of the patients (95% confidence interval 2·0–6·3%). Twelve events were diagnosed during intensification, all of which resolved within 2 weeks without neurological sequelae or significant impact in survival. Obesity (body mass index above 95th percentile) and asparaginase formulation were the only factors associated with CNS thrombosis, with an increase in the odds of event in obese patients [odds ratio (OR) = 3·37; P = 0·064] and a reduction in patients receiving Erwinia asparaginase (OR = 0·12; P = 0·018). No association could be demonstrated for age, gender, DFCI risk‐group, ALL phenotype, steroid or doxorubicin use, central venous line use or CNS radiotherapy. CNS thrombosis is a rare but manageable adverse event without significant sequelae or detrimental effects in survival. Increased awareness is recommended in obese patients particularly during intensive asparaginase use.     

Characteristics and outcomes of patients with multiple myeloma aged 21–40 years versus 41–60 years: a multi‐institutional case‐control study

We compared the outcomes of multiple myeloma (MM) patients aged 21–40 and 41–60 years in the novel agent era. This case‐control study included 1089 patients between 2000 and 2015. Cases and controls were matched for sex, International Staging System (ISS) stage and institution. There were 173 patients in the younger group and 916 patients in the older group. Younger patients presented with a higher incidence of lytic lesions (82% vs. 72%; P = 0·04) and high‐risk cytogenetic abnormalities (83% vs. 68%; P = 0·007), but lower rate of elevated lactate dehydrogenase (21% vs. 44%; P < 0·001). Five‐ and 10‐year overall survival (OS) in younger versus older patients was 83% vs. 67% and 56% vs. 39%, respectively (P < 0·001). Similar results were seen when studying the subset of 780 patients who underwent autologous transplantation. Younger patients with ISS stage 1 had a better OS than older patients (P < 0·001). There was no survival difference between younger and older patients with ISS stage 2 or 3. Younger MM patients, aged 21–40 years, treated in the era of novel agents have a better OS than their counterparts aged 41–60 years, but the survival advantage observed in younger patients was lost in more advanced stages of MM.