Superior treatment results in females with high-risk acute lymphoblastic leukemia in childhood

Characterization of pediatric acute lymphoblastic leukemia survival patterns by age at diagnosis

Age at diagnosis is a key prognostic factor in pediatric acute lymphoblastic leukemia (ALL) survivorship. However, literature providing adequate assessment of the survival variability by age at diagnosis is scarce. The aim of this study is to assess the impact of this prognostic factor in pediatric ALL survival. We estimated incidence rate of mortality, 5-year survival rate, Kaplan-Meier survival function, and hazard ratio using the Surveillance Epidemiology and End Results (SEER) data during 1973–2009. There was significant variability in pediatric ALL survival by age at diagnosis. Survival peaked among children diagnosed at 1–4 years and steadily declined among those diagnosed at older ages. Infants (<1 year) had the lowest survivorship. In a multivariable Cox proportional hazard model stratified by year of diagnosis, those diagnosed in age groups 1–4, 5–9, 10–14, and 15–19 years were 82%, 75%, 57%, and 32% less likely to die compared to children diagnosed in infancy, respectively. Age at diagnosis remained to be a crucial determinant of the survival variability of pediatric ALL patients, after adjusting for sex, race, radiation therapy, primary tumor sites, immunophenotype, and year of diagnosis. Further research is warranted to disentangle the effects of age-dependent biological and environmental processes on this association.

Role of chemotherapy prior to orchiectomy in metastatic testicular cancer-is testis really a sanctuary site?

A germ-cell tumour (GCT) of the testis is a chemosensitive tumour with high cure rates even in advanced disease. Radical inguinal orchiectomy is the initial procedure used to diagnose it which helps to risk-stratify these patients. However, in patients with life-threatening metastases, primary chemotherapy was attempted in a few studies, followed by delayed orchiectomy. The aim of this review is to study the histopathological findings of delayed orchiectomy and the retroperitoneal lymph node dissection (RPLND) specimens, to assess difference and concordance in response rates in histological types of GCTs in pathological specimens. Overall, 352 patients received initial chemotherapy followed by orchiectomy, and 235 of them had undergone RPLND. Delayed orchiectomy specimens had viable tumour in 74 (21%) patients, scarring/necrosis in 171 patients (48.5%), and teratoma in 107 (30.3%) patients. RPLND specimens had residual disease in 36 (15.3%) patients, scarring/necrosis in 100 patients (42.5%), and teratoma in 99 patients (42.3%). Patients with seminoma who underwent delayed orchiectomy had complete disappearance of tumour in 81.3% of cases, and in non-seminomatous GCT, it was 43.4%. These results raise the question of the existence of a blood–testis barrier in patients with advanced GCT and argue against the testis as a sanctuary site.

Sex variability in pediatric leukemia survival: large cohort evidence

Purpose. Sex disparities in pediatric leukemia have been previously reported, and male children continue to present with poorer survival. However, the observed disparities are not fully understood. This current study sought to examine disparities in survival by the sex, and to determine if tumor prognostic factors impact on these disparities. Patients and Methods. We used the Surveillance Epidemiology and End Results dataset of pediatric leukemia patients (ages 0–19 years) diagnosed in the United States from 1973 to 2006. There were 15,215 patients of whom 8,622 (65.7%) were boys and 6,593 (43.3%) were girls. The Kaplan-Meier survival estimates, log rank test, and Cox proportional hazard methods were used to assess the data. Results. The overall (both sexes) five-year survival rate was 67.9%. Girls had a survival rate of 70.1%, while the rate was 66.3% in boys. Girls had a significant 14% decreased risk of dying relative to boys, hazard ratio (HR) = 0.86, 99% CI = 0.80–0.93. There were significant differences between boys and girls with respect to tumor cell type, race, age at diagnosis, year of diagnosis, and number of primaries, P < 0.001. After controlling for these factors, the sex differences in survival persisted, with girls still less likely to die from leukemia compared to boys, adjusted HR (AHR) = 0.85, 99% CI = 0.72–1.00, P < 0.01. Conclusion. In a large population-based pediatric leukemia study, boys continued to show poorer survival. These disparities were not completely explained by treatment received, tumor prognostic or socio-demographic factors.

Intensification of mercaptopurine/methotrexate maintenance chemotherapy may increase the risk of relapse for some children with acute lymphoblastic leukemia

PURPOSE

Thioguanine nucleotides (TGNs) mediate the cytotoxicity of mercaptopurine (MP). Methylated MP metabolites (formed by thiopurine methyltransferase [TPMT]) and methotrexate (MTX) polyglutamates can inhibit de novo purine synthesis. We explored whether dose adjustment of MP and MTX by erythrocyte (E) levels of TGN and MTX (including polyglutamates) could improve outcome in childhood acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

A total of 538 children with ALL were randomly assigned to have their oral MP/MTX maintenance therapy adjusted by white cell counts (WBC), E-TGN, and E-MTX (pharmacology group), or by WBC only (control group).

RESULTS

After a median follow-up of 7.8 years, 79 patients had relapsed. Cox regression analysis showed an increased risk of relapse for boys (P =.00003), high WBC at diagnosis (P =.03), pharmacology arm (6.6 times increased relapse hazard for girls), high TPMT activity (P =.002), and high average neutrophil counts during maintenance therapy (P =.0009), with a significant interaction between sex and randomization group (P =.0007). For girls, the relapse risk was 5% in the control group and 19% in the pharmacology group (P =.001) because of an increased relapse hazard during the first year after cessation of therapy. TPMT activity was the most significant predictor of relapses among girls in the pharmacology arm (P <.0001). Overall, the TPMT activity was higher for patients who relapsed after cessation of therapy compared with those who stayed in remission (girls 19.5 v 17.4 U/mL, P =.03; boys 19.3 v 18.0 U/mL, P =.04).

CONCLUSION

Adding pharmacologically guided treatment intensification to dose adjustments by blood counts may not be warranted for girls, whereas new approaches to optimize maintenance therapy are needed for boys.

Outcome of acute lymphoblastic leukemia in children with AL90 regimen: impact of response to treatment and sex difference on prognostic factors

BACKGROUND

In our previous studies, the outcome of high-risk ALL was still poor. In the present study, all children with ALL were classified into three groups and treated with a new regimen (AL90).

PATIENTS AND METHODS

Between 1990 and 1996, 220 children with ALL, treated with the AL90 regimen, were classified into three risk groups: low, intermediate, and high: LR, IR, and HR, respectively. The protocol consisted of three- to five-drug induction, consolidation with intermediate-dose methotrexate and/or cytarabine, mercaptopurine and cyclophosphamide, four-drug intensification, and sequential maintenance therapies. Only intrathecal chemotherapy was used for CNS prophylaxis in the LR group, whereas cranial irradiation was added for the IR and HR groups.

RESULTS

The number of eligible patients was 91: LR group, 71: IR group, and 58: HR group. Complete remission (CR) was obtained in > 98% of the LR and IR groups, while only 88% achieved CR in the HR group. The 5-year event-free survival (EFS) rate was 67.4% in all patients: 70.4% in the LR group, 71.7% in the IR group, and 57.5% in the HR group. With respect to the previous study, EFS in the HR group who showed positive residual leukemia at 14 days was improved, whereas EFS in boys versus girls was significantly lower (48.8% : 85.7%, P = 0.02).

CONCLUSIONS

In high-risk ALL, the rate of induction failure was high and boys had a worse outcome, calling for improvements in induction therapy and a specific approach for boys.

Individualized methotrexate dosing in children with relapsed acute lymphoblastic leukemia

Although high-dose methotrexate has been extensively studied in children with newly diagnosed acute lymphoblastic leukemia (ALL), there are fewer data in children with relapsed ALL, many of whom have been heavily pretreated and have subclinical kidney dysfunction. We characterized the pharmacokinetics of adaptively controlled methotrexate given as a 24-h infusion during consolidation therapy in 24 children with relapsed ALL. To achieve the target steady-state concentration of 65 microM, dosage adjustments were required in 14 patients, with doses ranging from 2854 to 6700 mg/m2 per course. The mean steady-state plasma concentration (Cpss) of 68.0 microM was different (P = 0.025) than the predicted Cpss (mean = 87.4 microM; range 35.7-184 microM) had no adjustment in dose been made. The coefficient of variation in Cpss was reduced from 41% to 18% by individualizing doses. Predisposing factors that correlated with decreased methotrexate clearance were female sex (P = 0.03), age greater than 6 years (P = 0.01), and prior history of heavy amphotericin B treatment (>30 mg/kg) (P = 0.03), but no factor predicted low clearance as well as the measured initial methotrexate clearance during the infusion (P < 0.0001). There was no life-threatening toxicity with the regimen. We conclude that dosage individualization decreases interpatient variability and avoids potentially toxic methotrexate exposures in heavily pretreated ALL patients.

A comparative pharmacokinetic study of doxorubicin and 4'-epi-doxorubicin in children with acute lymphocytic leukemia using a limited sampling procedure

Antraquinone glycosides are an important class of antineoplastic drugs, frequently used for treatment of a variety of malignancies in children. Doxorubicin (Dox) is the most frequently used drug within this class of antineoplastics. 4'-epi-doxorubicin (Epi), a Dox isomer, was developed with the aim of reducing risks for fatal heart toxicity observed with Dox. The aim of the present study was to investigate the pharmacokinetics of Dox and Epi in children with acute lymphocytic leukemia. In total 31 patients (13 females and 18 males; median age 5.4 years; range 0.73-15.3 years) were studied using a simplified sampling procedure. The pharmacokinetic differences of the two drugs were established by their simultaneous administration. The plasma pharmacokinetics of neither Dox nor Epi correlated with the age of the patients. There were no gender differences in dose-normalized maximum concentrations of neither Dox nor of Epi. The inter-patient variation of the dose-normalized maximum concentrations of Dox and Epi is larger among females than among males. The Cmax ratio Dox/Epi was 1.39+/-0.19 (mean +/- SD). The pharmacokinetic differences of Dox and Epi in children, although less pronounced than in adults, are still of a magnitude that might be of clinical importance.

Sex differences in prognosis for children with acute lymphoblastic leukemia

PURPOSE

Whether recent improvements in the treatment of childhood acute lymphoblastic leukemia (ALL) have nullified the adverse prognosis associated with male sex remains unclear. Therefore, we analyzed the survival experience and presenting clinical and laboratory features of boys and girls with newly diagnosed ALL who were treated at our institution over the past three decades.

PATIENTS AND METHODS

One thousand one hundred fifty-one boys and 904 girls were treated in 13 consecutive Total Therapy studies between 1962 and 1994. An overview analysis was used to investigate the impact of sex on overall and event-free survival, both for the entire cohort and for subgroups defined by treatment era and blast-cell immunophenotype. Stratified analyses were performed to adjust for treatment protocol and known risk factors, and in the modern treatment era, for protocol, immunophenotype, and the DNA content of leukemic cells (ie, DNA index). The pharmacokinetics of methotrexate, teniposide, and cytarabine, as well as the thiopurine methyltransferase activity of erythrocytes, were compared between boys and girls treated on a single protocol.

RESULTS

Compared with girls, boys were more likely to have T-cell ALL (20.9% v 10.7%, P < .001) and seemed less likely to have a favorable DNA index (17.8% v 25.1%, P = .072). There were no other statistically significant differences between the two sexes with respect to presenting features, including leukemic-cell genetic abnormalities, nor were there significant sex differences in the pharmacokinetics of methotrexate, teniposide, or cytarabine or in erythrocyte thiopurine methyltransferase activity. Girls clearly fared better than boys (P < .001) on protocols used during the early era of treatment (10-year event-free survival +/- 1 SE, 43.1%+/-2.1% v 31.5%+/-1.7%). Although prognosis improved for both sexes in the modern era, the difference in outcome between girls and boys persisted (P = .025) (10-year event-free survival, 73.4%+/-3.7% v 63.5%+/-4.0%). However, stratification of modern-era patients by protocol, immunophenotype, and DNA index mitigated statistical evidence of a sex difference in overall survival (P = .263) and event-free survival (P = .124).

CONCLUSION

Although boys and girls alike have benefited from improvements in ALL therapy, these gains have not completely eliminated the sex difference in prognosis that has persisted since the early 1960s. The apparent difference in outcome is partially explained by differences between boys and girls in the distributions of ALL immunophenotype and DNA index.

Reduced bone density at completion of chemotherapy for a malignancy

OBJECTIVES

Osteoporosis and pathological fractures occur occasionally in children with malignancies. This study was performed to determine the degree of osteopenia in children with a malignancy at completion of chemotherapy.

METHODS

Lumbar spine (L2-L4) bone mineral density (BMD; g/cm2) and femoral neck BMD were measured by dual energy x ray absorptiometry in 22 children with acute lymphoblastic leukaemia (ALL), and in 26 children with other malignancies. Apparent volumetric density was calculated to minimise the effect of bone size on BMD. Results were compared with those of 113 healthy controls and expressed as age and sex standardised mean Z scores.

RESULTS

Patients with ALL had significantly reduced lumbar volumetric (-0.77) and femoral areal and volumetric BMDs (-1.02 and -0.98, respectively). In patients with other malignancies, femoral areal and apparent volumetric BMDs were significantly decreased (-0.70 and -0.78, respectively).

CONCLUSIONS

The results demonstrate that children with a malignancy are at risk of developing osteopenia. A follow up of BMD after the completion of chemotherapy should facilitate the identification of patients who might be left with impaired development of peak bone mass, and who require specific interventions to prevent any further decrease in their skeletal mass and to preserve their BMD.

Polymerase chain reaction-single-strand conformational polymorphism analysis of antigen receptor rearrangements in monitoring therapeutic effect in childhood ALL

The rearrangement of the immunoglobulin heavy chain (IgH) genes can be used as a marker of cell lineage and clonality. The polymerase chain reaction (PCR) technique using consensus primers for the IgH gene was used for remission and minimal residual disease (MRD) analysis in the follow-up of childhood acute lymphoblastic leukemia (ALL) of B-cell lineage. Single-strand conformational polymorphism (SSCP) was used to distinguish the specific clonal amplicons from the background. The Authors found that, in a series of 22 patients followed-up for 5.3 to 11.1 years, the PCR-SSCP technique could detect at least one rearrangement at initial diagnosis in 21 (95%). All patients who remained in continuous complete remission were PCR-SSCP negative at remission controls. Ten of the 22 patients had one or more bone marrow relapses. The PCR-SSCP method demonstrated MRD in three of them. In 6 of the 7 (86%) of patients with disease recurrence from whom samples were taken within 6 months before a clinically overt relapse, PCR-SSCP became positive. The Authors conclude that PCR-SSCP of a rearrangement marker might have a role as a convenient technique for monitoring emerging relapse. It may also detect unrelated clones or ongoing secondary recombination events during progression. However, PCR-SSCP is not sensitive enough to detect MRD in all patients in whom disease will later recur.

Reduced bone mineral density in long-term survivors of childhood acute lymphoblastic leukemia

PURPOSE

Osteoporosis and pathologic fractures are occasionally found in patients with childhood acute lymphoblastic leukemia (ALL). This study was performed to determine the degree of possible osteopenia in long-term survivors of childhood ALL.

PATIENTS AND METHODS

Lumbar spine (L2-L4) and femoral neck bone mineral densities (BMDs) (g/cm2) were measured in 29 survivors (aged 12 to 30 years, median 17) of childhood ALL 2 to 20 (median 8) years after discontinuation of chemotherapy. These results were compared with those from 273 healthy controls and expressed as a percentage of the age- and sex-matched control values (mean +/- standard deviation).

RESULTS

Lumbar and femoral BMDs were significantly reduced in survivors of childhood ALL. Particularly, male gender (lumbar: 91.7 +/- 10.4%, p = 0.008; femoral: 91.9 +/- 11.3%, p = 0.005) and a history of cranial irradiation (lumbar: 93.0 +/- 8.9%, p = 0.005; femoral: 94.4 +/- 13.3%, p = 0.03) were associated with low lumbar and femoral BMDs.

CONCLUSIONS

The detected deficit in bone density in survivors of childhood ALL may predispose these patients to osteoporotic fractures later in adulthood. A follow-up of BMD in survivors of childhood ALL should facilitate the identification of patients who would require specific therapeutic interventions to prevent further decrease of their skeletal mass and preserve their BMD.

Survival and endocrine outcome after testicular relapse in acute lymphoblastic leukaemia

Survival and endocrine status in a cohort of boys with acute lymphoblastic leukaemia (ALL) who started treatment between 1972 and 1987 and subsequently developed a testicular relapse were analysed. During this period there was a significant improvement in the overall event free survival for boys, but no significant decrease in the testicular relapse rate. Thirty three boys had an apparently isolated testicular relapse, whereas 21 boys had a combined relapse. The event free survival for boys with an isolated testicular relapse was 59% at six years (95% confidence interval (CI) 42 to 74%). The event free survival for the 16 patients with a combined relapse who received a second course of treatment was 32% (95% CI 17 to 60%). Those patients receiving adequate second line treatment for an isolated testicular relapse whose first remission was longer than or equal to two years had an event free survival of 82% (95% CI 63 to 93%) at six years. No boy relapsing within two years from diagnosis has survived. Endocrine late effects are significant, with 82% of the boys requiring hormonal treatment at some stage for induction of puberty or continuing pubertal maturation, or both. It is concluded that, despite the increasing intensity of initial treatment for ALL, isolated testicular relapse is treatable by conventional means in most patients. Careful endocrine follow up of these patients is essential as most will require hormone replacement treatment.

Is there a gender difference in red blood cell thiopurine methyltransferase activity in healthy children?

We have examined red blood cell (RBC) thiopurine methyltransferase (TPMT) activity in a healthy population sample of Norwegian children, age 1-10 years. Boys had mean RBC TPMT activity of 11.1 +/- 2.0 U (n = 87) vs. 10.6 +/- 2.2 U (n = 71) in girls, the difference was not significant (P = 0.3). Age was negatively correlated to RBC TPMT activity (rs = -0.2, P = 0.01). As boys with acute lymphoblastic leukemia (ALL) tolerate more 6-mercaptopurine (6-MP) than girls and have a higher risk of relapse, we have searched for pharmacokinetic causes of these gender differences. The gender difference in 6-MP tolerance and clinical outcome in children with ALL cannot be explained by the minor and nonsignificant higher RBC TPMT activity in boys compared to girls.

Outcome after first relapse in children with acute lymphoblastic leukemia: a population-based study of 315 patients from the Nordic Society of Pediatric Hematology and Oncology (NOPHO)

This study reports the outcome after relapse of acute lymphoblastic leukemia (ALL) in a population-based study of 809 children over 1 year of age diagnosed July 1981 through June 1986 and with non-B acute lymphoblastic leukemia in the five Nordic countries. By January 1994, 315 children had suffered at least one relapse. The bone marrow was involved in 216 cases. There were 69 isolated CNS relapses, 25 isolated testicular recurrences and five relapses in other extramedullary sites. Of the 315 children with relapse, 94 are still in a second complete remission 12-138 (median: 78) months after relapse. The overall probability of a second event free survival (P-2.EFS) and survival after relapse was 0.28 and 0.33 respectively. The probability of remaining in second remission at 11 years was significantly correlated to the duration of first remission (P < 0.001), the site of relapse (P < 0.001) and gender (P = 0.004). The P-2.EFS for early, intermediate, and late bone marrow involved relapses were 0.08, 0.19, and 0.50 respectively. For early, intermediate and late isolated CNS relapses the P-2.EFS were 0.21, 0.38 and 0.61, respectively. The P-2.EFS for boys with isolated testicular relapses was 0.69. Girls with isolated CNS relapse (P < 0.001) and with bone marrow involved relapse (P = 0.04) had a significantly better prognosis than boys. Children with initial high risk criteria, especially T-ALL and mediastinal mass who relapsed, had a very poor prognosis.

CONCLUSION

In this population-based study, about 30% of children with ALL obtained a long second remission and possible cure.

Gender and treatment outcome in childhood lymphoblastic leukaemia: report from the MRC UKALL trials

We have examined the factors influencing prognosis in over 4000 children with acute lymphoblastic leukaemia (ALL) aged 1-14 who have been treated on consecutive MRC UKALL trials from 1972 to 1990. During this time the results of treatment have improved steadily but are consistently superior in girls when compared with boys; the 5-year event-free survival in girls improving from 51% to 71% and in boys from 31% to 57%. These results were independent of age and presenting leucocyte count. Boys not only had a testicular relapse rate of 10% but an excess of bone marrow relapse, particularly evident after 2 years from diagnosis. Other prognostic factors included organomegaly and the morphology of leukaemic blast cells; immunophenotype of the leukaemia, however, had no independent significance after allowance for age, sex and leucocyte count. The influence of sex on prognosis was reaffirmed when we examined various methods of identifying children at highest risk of treatment failure for whom alternative therapy such as bone marrow transplantation might be justified. In MRC UKALL X children had been deemed 'high risk' on the basis of leucocyte count alone, but with further follow-up it has become apparent that girls with an initial leucocyte count of > 100 x 10(9)/l have a similar prognosis to boys with a lower count. We therefore derived a risk score based on sex, age and count which has given better discrimination between standard risk (66% 5-year survival) and poor risk (39%) survival than other methods. This group of worse-risk children includes 16% of boys but only 3% of all girls. Gender remains an important prognostic factor in UKALL trials and there are very few girls who are at highest risk of treatment failure. The reasons for this remain unclear, but the pattern of relapses suggests that boys more often get inadequate systemic therapy. We postulate that the reasons for treatment failure may relate to sensitivity to continuing (maintenance) chemotherapy.