Recent advances in management of acute leukaemia

Characteristics of De Novo Acute Myeloid Leukemia Patients in Palestine: Experience of An-Najah National University Hospital

Objective:

To describe the characteristics of de novo acute myeloid leukemia (AML) in the Palestinian population.

Study design and setting:

A retrospective chart review study was conducted at An-Najah National University Hospital (NNUH) during the period of January, 2014 to December, 2016.

Methodology:

The medical records of AML patients treated at NNUH were reviewed. All patients at least 16 years of age diagnosed with de novo AML and started on induction chemotherapy were included. Descriptive statistics were employed to analyze the data.

Results:

Out of 88 patients diagnosed with AML during the study period, 64 had de novo AML and were included. Median age at diagnosis was 36 years, with a male to female ratio of 1.13:1. Two thirds of the cases were from the West Bank and the remainder were from Gaza. Major complaints at presentation were fatigue (64.1%), fever (46.9%), respiratory tract infections (39.1%) and bruising (28.1%). Hepatomegaly was present in 23.4% and splenomegaly in 34.4%. At presentation, the median white blood cells (WBC) count, hemoglobin (Hb) concentration and platelet count were 30. 5x10⁹/L, 9.3g/dL, and 39.5 x10⁹/L, respectively. According to the French American British (FAB) classification, M4 was the most common subtype (32.8%) followed by M3 (21.9%). After a single cycle of induction chemotherapy complete remission (CR) was seen in 26 (41.9%) and non-remission (NR) in 17 (27.4%), while 19 patients (30.6%) died during the first admission for induction.

Conclusion:

The characteristics of de novo AML in Palestinian patients are comparable to published data elsewhere. M4 was the most common subtype. The outcome of the first cycle of induction chemotherapy was slightly inferior to the published data for M3 patients. Further studies are warranted to identify possible causes.

Analysis of outcomes and prognostic factors of acute lymphoblastic leukemia patients treated by MCP841 protocol: A regional cancer center experience

Background:

A dramatic improvement in the survival of acute lymphoblastic leukemia (ALL) patients in the last three decades has been observed. MCP 841 protocol is an old but effective tool with tolerable toxicities. The objective of this study was to estimate the relapse-free survival of ALL patients treated uniformly with MCP 841 protocol on the basis of various prognostic factors.

Materials and Methods:

The study design was retrospective and it was conducted in a regional cancer center of Northwest India. Three hundred and ten ALL patients who underwent treatment with MCP 841 protocol and regular follow-up for up to 5 years were selected for this study. Relapse-free survival was calculated by Kaplan–Meier analysis and Cox regression analysis was used to calculate the hazards ratio (HR) using Statistical Package for the Social Sciences (SPSS) software for windows version 20.0.

Results:

Fifty-four percent patients were <15 years of age and 69% were males. 53.2% patients were in remission at the end of 5 years of starting the treatment. Relapse-free survival at 5 years by Kaplan–Meir analysis for B-cell ALL was 62% [HR 0.67 {95% confidence interval (CI) 0.47-0.95}] with patients with unknown lineage taken as reference] while for T cell it was 28% [HR 1.41 (95% CI 1.19-1.63), P 0.001]. Patients with total leukocyte count (TLC) <1 lakh/cmm at presentation, relapse-free survival was 68% and those with TLC >1 lakh/cmm had 41% survival [HR 2.14 (1.76-2.48) with, P < 0.001].

Conclusion:

MCP 841 protocol is a useful tool for the treatment of ALL in children when more aggressive protocols can not be used.

Molecular cytogenetics in childhood acute lymphoblastic leukemia: a hospital-based observational study

OBJECTIVE

This study was conducted to determine the frequency of chromosomal aberrations in children aged <19 years with newly diagnosed acute lymphoblastic leukemia (ALL), attending/admitted in the Department of Pediatrics and Radiotherapy, Government Medical College, Jammu. Furthermore, we aimed to study the correlation between the cytogenetic molecular abnormalities and the immediate clinical outcome (induction of remission).

MATERIALS AND METHODS

This was a prospective study conducted over a period of 2 years (May 2011 to May 2013) in a tertiary care hospital in India. Forty pediatric (1-19 years) patients (18 males, 22 females; M: F = 0.8 : 1) with newly diagnosed ALL were studied for molecular cytogenetic analysis. Written consent was obtained from the parents of the patients. Bone marrow aspiration was done for making the diagnosis of ALL. Children lost to follow-up and who failed to give consent were excluded from the survey. Host factors and clinical parameters were obtained from patients.

RESULTS

Bone marrow aspirate samples of 40 diagnosed cases of ALL were subjected to routine cytogenetic analysis, and reverse transcription-polymerase chain reaction (RT-PCR) technique was used for molecular analysis. Well-spread metaphase plates were obtained in 18/40 (45%) cases for analysis. RT-PCR revealed abnormal genes in 20/40 (50%) patients. The results of molecular cytogenetic analysis were correlated with patients' clinical and hematological parameters for risk stratification and immediate outcome (induction of remission). Eighteen out of 40 (45%) cases revealed no abnormality. Among the remaining 22 cases, 8 had TEL-AML1 (20%), 6 had BCR-ABL (15%), 4 had MLL-AF4 (10%), 2 had E2A-PBX1 (5%) fusion genes, and 2 had hyperdiploidy. To conclude, a higher proportion of cases in this study showed adverse translocations such as t (9;22), t (4;11), and t (1;19) compared to that reported in literature.

CONCLUSION

RT-PCR assay was useful in detecting the prognostically significant oncogene fusion transcripts. In our study of 40 patients, we found that the pattern and frequency differ from those reported in Western literature. Our study reveals a lower frequency of hyperdiploidy (5%) and a higher frequency of BCR-ABL gene fusion (20%) in childhood ALL. Above all, in contrast to previous studies on childhood ALL, our study showed female predominance, with the male-to-female ratio being 0.8 : 1. Apart from the BCR-ABL fusion gene, none other was associated with poor prognosis. It is already well established that the characterization of the genetic entities at diagnosis is crucial for the understanding and the optimal treatment of ALL. Because the aberrations in our population differ significantly from those reported in Western populations, we may be required to tailor our protocols.

Compliance with a protocol for acute lymphoblastic leukemia in childhood

Background

Remission rates achieved after the initial treatment of acute lymphoblastic leukemia may be similar in both developed and developing countries, but relapse rates are much higher in the latter. Thus, other reasons are needed, in addition to biological characteristics of the leukemic cells themselves, to explain the unfavorable evolution of patients living in unfavorable socioeconomic and cultural conditions.

Objective

The aim of this study was to retrospectively evaluate compliance to an acute lymphoblastic leukemia treatment protocol.

Methods

Main abstracted data were: total duration and reasons for interruption of chemotherapy, prescribed doses of 6-mercaptopurine, and median white blood cell and neutrophil counts during the maintenance phase. Interruptions of chemotherapy were considered inappropriate if they did not follow predetermined criteria established in the protocol.

Results

Fourteen of 73 patients (19.2%) unduly interrupted chemotherapy by determination of their physicians. The median white blood cell count was higher when compared with the protocol recommendations; the median 6-MP dose was lower than the standard recommended dose. The estimated probability of event-free survival was higher for patients with lower median leukocyte counts and close to those predetermined by the protocol. Event-free survival was also higher for children with a higher percentage of days without chemotherapy due to bone marrow or liver toxicity excluding undue interruptions. In multivariate analysis, both factors remained statistically significant. These results suggest that the intensity of maintenance chemotherapy may not have been enough in some children, to achieve adequate myelosuppression, hence the observation of higher leukocyte counts and none or rare episodes of therapy interruption.

Conclusions

Compliance to the therapeutic protocol by both doctors and patients should always be considered in the evaluation of therapeutic failure in acute lymphoblastic leukemia; strict adherence to treatment protocols contributes to better treatment results in acute lymphoblastic leukemia children.

Pattern of mortality in childhood acute lymphoblastic leukemia: experience from a single center in northern India

The outcome of acute lymphoblastic leukemia (ALL) in developing countries is inferior compared with the resource-rich nations. This descriptive study was designed to determine the pattern of deaths in children with ALL treated at a single center and identify the problem areas in management. Case records of 532 patients with ALL were analyzed. Information regarding the clinical-demographic profile, therapy, and course of illness were recorded. One hundred twenty-eight (24.0%) deaths were recorded. Sepsis (53.3%) and bleeding (15.7%) were the most common causes of mortality. The mortality rate fell significantly during the induction and remission phases of the therapy in 2 consecutive time periods between 1990 to 1997 and 1998 to 2006. The factors associated with an increased risk of death were longer symptom diagnosis interval (P=0.049), bulk disease (P=0.008), mediastinal adenopathy (P=0.001), higher total leukocyte count (P=0.001), and lower platelet count (P=0.007) at presentation as compared with the survivors. Multivariate analysis showed that longer symptom diagnosis interval (P=0.001), mediastinal adenopathy (P=0.006), lower platelet count (P=0.001), and higher total leukocyte count significantly influenced death. The estimated median time to death for the induction and remission deaths were 0.5 and 17 months, respectively. A high mortality rate necessitates the reappraisal of our treatment protocols. Many deaths should be avoidable by the provision of adequate supportive care, close supervision during and after chemotherapy, and appropriate antibiotic and antifungal therapy.

Pattern of relapse in childhood ALL: challenges and lessons from a uniform treatment protocol

This retrospective analysis of 254 children less than 15 years of age treated with MCP-841 protocol from June 1992 to June 2002 was undertaken to identify the pattern of relapse and determine management lacunae. Two hundred twenty-three (87.8%) children achieved a complete remission of whom 40 (17.9%) relapsed. The mean age of relapsed patients was 6.5 years. The male/female ratio was 9:1. There were 23 (57.5%) isolated bone marrow (BM), 7 (17.5%) isolated central nervous system (CNS), 2 (5%) isolated testicular, 5 (12.5%) BM+testes and 1 each of BM+CNS, CNS+testes, and isolated bone relapses. Twenty-seven children (67.5%) relapsed on-therapy whereas 13 (32.5%) relapsed posttherapy. All 9 CNS relapses occurred on-therapy whereas 5/8 (62.5%) of testicular relapses occurred posttherapy. Lymphadenopathy was the only significant predictor for relapse. High-risk features such as age less than 1 year and greater than 10 years (P=0.047) and white cell count greater than 50.0 x 10(9)/L (P=0.044) were significantly more frequent in patients with early on-therapy relapse than in patients with off-therapy relapse. The overall survival in the entire study cohort was 67+/-3.5%. Modest survival outcome, relapse while on chemotherapy and the higher incidence of CNS and testicular relapse indicate the need for reappraisal of our treatment protocol. There is a need of identifying risk factors and high-risk groups in our set of patients and risk-stratified intensification of chemotherapy in them.

Long-term results of the Japanese Childhood Cancer and Leukemia Study Group studies 811, 841, 874 and 911 on childhood acute lymphoblastic leukemia

We analyzed the long-term outcomes of 1021 patients with acute lymphoblastic leukemia (ALL), enrolled in four successive clinical trials (ALL811, ALL841, ALL874 and ALL911) between 1981 and 1993. All patients received risk-adopted therapy according to leukocyte count and age at the time of diagnosis. The median follow-up durations of the four studies were 17.8 years in ALL811, 15.5 years in ALL841, 11.9 years in ALL874 and 15.8 years in ALL911. Patients' event-free survival (EFS) and overall survival (OS) rates at 12 years were 41.0 and 54.3% in ALL811, 50.2 and 60.2% in ALL841, 57.3 and 64.7% in ALL874, and 63.4 and 71.7% in ALL911, respectively. Thus, cure can become a reality for about 70% of children with ALL. There is, however, still a significant difference in survival outcomes according to risk group. Late effects were observed in 70 patients out of 834 (8.4%); hepatitis and short stature were most commonly reported. Reduction of late adverse effects for all patients and development of new treatment strategies for very-high-risk patients are major issues for upcoming trials to address.

Pattern of relapsed disease in childhood all: experience from a single tertiary care center in North India

The study was designed to determine the pattern of relapsed disease and identify problem areas in management. Relapse occurred in 111 (23.9%) of the boys and 16 (13.0%) of the girls. The majority relapsed while on chemotherapy. Isolated relapse in the marrow and in the CNS was seen in 51 (40.8%) and 24 (18.9%) patients, respectively. Isolated testicular relapse was seen in 17 (15.3%) of the 111 boys who suffered a relapse. Age and TLC at initial presentation and gender in relapsers and nonrelapsers were compared. Multivariate regression analysis showed that gender (p = .03) and TLC (p = .001) were significant predictors of relapse. Relapse of disease while on chemotherapy and high incidence of CNS and testicular relapse indicate the need for reappraisal of treatment protocols.

Survival outcome in childhood ALL: experience from a tertiary care centre in North India

BACKGROUND

Survival of children with ALL, in developing nations has not kept pace with cure rates in developed countries. Our study was designed to assess survival data and identify risk factors.

PROCEDURE

Data of 762 patients with ALL were analyzed. Information regarding the clinical-demographic profile, therapy and course of illness were recorded. Status and duration at last follow-up were utilized to generate Kaplan-Meier survival curves.

RESULTS

The mean age was 5.7 +/- 0.23 years (M/F, 3.2:1). Parents of 230 (30.2%) patients opted for no therapy. There were 68 and 60 deaths in induction and remission phases respectively. Besides these, 111 children either defaulted therapy or were lost to follow up. Relapsed disease was documented in 125 cases. The 5-year OS and EFS was 46% and 43% respectively. Survival analysis, using the Cox multivariate regression, for gender (P = 0.659, CI: 0.852-1.161), age (P = 0.943, CI: 0.725-1.225), symptom-diagnosis interval (P = 0.002, CI: 1.116-1.668), WCC (P < 0.001, CI: 1.353-1.814) and platelet count (P = 0.001, CI: 0.546-0.849) was performed. Bulk disease (P = 0.049, CI: 0.428-0.986), mediastinal adenopathy (P = 0.045, CI: 1.040-3.697), WCC (P = 0.016, CI: 1.395-2.691), platelet count (P = 0.031, CI: 0.431-0.967) and administration of 2 intensification blocks (P = 0.012, CI: 0.624-0.940) were found to be significant predictors of outcome by multivariate analysis.

CONCLUSIONS

The management of ALL requires financial resources and access to quality supportive care. One third of our patients opted for no therapy. The other problem areas were a high proportion of therapy defaulters, lost to follow up and infection related deaths during induction and remission phases. The introduction of remedial measures for resolving the difficulties identified would hopefully improve cure rates in ALL in developing nations.

Prognostic value of minimal residual disease quantification before allogeneic stem-cell transplantation in relapsed childhood acute lymphoblastic leukemia: the ALL-REZ BFM Study Group

PURPOSE

Minimal residual disease (MRD) before allogeneic stem-cell transplantation was shown to predict outcome in children with relapsed acute lymphoblastic leukemia (ALL) in retrospective analysis. To verify this, the Acute Lymphoblastic Leukemia Relapse Berlin-Frankfurt-Münster (ALL-REZ BFM) Study Group conducted a prospective trial.

PATIENTS AND METHODS

Between March 1999 and July 2005, 91 children with relapsed ALL treated according to the ALL-REZ BFM 96 or 2002 protocols and receiving stem-cell transplantation in >or= second remission were enrolled. MRD quantification was performed by real-time polymerase chain reaction using T-cell receptor and immunoglobulin gene rearrangements.

RESULTS

Probability of event-free survival (pEFS) and cumulative incidence of relapse (CIR) in 45 patients with MRD >or= 10(-4) leukemic cells was 0.27 and 0.57 compared with 0.60 and 0.13 in 46 patients with MRD less than 10(-4) leukemic cells (EFS, P = .004; CIR, P < .001). Intermediate-risk patients (strategic group S1) with MRD >or= 10(-4) leukemic cells (n = 14) had a pEFS of 0.20 and CIR of 0.73, whereas patients with MRD less than 10(-4) leukemic cells (n = 21) had a pEFS of 0.68 and CIR of 0.09 (EFS, P = .020; CIR, P < .001). High-risk patients (S3/4, third complete remission) who received transplantation with an MRD load of less than 10(-4) leukemic cells (n = 25) showed a pEFS and CRI of 0.53 and 0.18, respectively. In contrast, pEFS and CRI were 0.30 and 0.50 in patients who received transplantation with an MRD load of >or= 10(-4) leukemic cells. Multivariate Cox regression analysis revealed MRD as the only independent parameter predictive for EFS (P = .006).

CONCLUSION

MRD is an important predictor for post-transplantation outcome. As a result, new strategies with modified stem-cell transplantation procedures will be evaluated in ALL-BFM trials.

Follow-up care for young adult survivors of cancer: lessons from pediatrics

INTRODUCTION

Recent advances in treatment of childhood cancer have resulted in overall survival rates approaching 75%, but approximately two-thirds experience late-effects related to the disease or treatment. Consequently, recommendations for comprehensive follow-up have been made. As the number of survivors of adult cancers increase, similar concerns about how to provide follow-up and achieve optimal quality of life are being raised. In this paper we propose that management of cancer survivors diagnosed in young adulthood (18-45 years) could benefit from experience gained treating survivors of childhood cancer.

MATERIALS AND METHODS

We reviewed research relating to differences in survival rates and late-effects; current arrangements for follow-up; effectiveness; and problems in organization of follow-up separately for survivors of child and adult cancers.

RESULTS

A number of models of follow-up were identified. Rationale for follow-up included early identification and treatment of second cancer and late-effects, health promotion and screening. Increasing numbers of survivors and range of late-effects were identified as problems in organizing services. A possible solution is risk-stratified follow-up, currently being developed in pediatrics.

CONCLUSIONS

New models of follow-up are needed that take account of financial costs for health services and survivors' concerns about their current and future health. Implications for continuing refinement of treatment protocols must be an integral part of the service.

IMPLICATIONS FOR CANCER SURVIVORS

International standards are needed to ensure all survivors have access to expert follow-up care and can benefit from new information that might lead to earlier treatment of late-effects.

Prediction of relapse in paediatric pre-B acute lymphoblastic leukaemia using a three-gene risk index

Despite high cure rates 25% of children with acute lymphoblastic leukaemia (ALL) relapse and have dismal outcome. Crucially, many are currently stratified as standard risk (SR) and additional markers to improve patient stratification are required. Here we have used diagnostic bone marrow specimens from 101 children with pre-B ALL to examine the use of gene expression profiles (GEP) as predictors of long-term clinical outcome. Patients were divided into two cohorts for model development and validation based on availability of specimen material. Initially, GEP from 55 patients with sufficient material were analysed using HG-U133A microarrays, identifying an 18-gene classifier (GC) that was more predictive of outcome than conventional prognostic parameters. After feature selection and validation of expression levels by quantitative reverse transcription polymerase chain reaction (qRT-PCR), a three-gene qRT-PCR risk index [glutamine synthetase (GLUL), ornithine decarboxylase antizyme inhibitor (AZIN), immunoglobulin J chain (IGJ)] was developed that predicted outcome with an accuracy of 89% in the array cohort and 87% in the independent validation cohort. The data demonstrate the feasibility of using GEP to improve risk stratification in childhood ALL. This is particularly important for the identification of patients destined to relapse despite their current stratification as SR, as more intensive front-line treatment options for these individuals are already available.

Proton pump inhibitors induce apoptosis of human B-cell tumors through a caspase-independent mechanism involving reactive oxygen species

Proton pumps like the vacuolar-type H+ ATPase (V-ATPase) are involved in the control of cellular pH in normal and tumor cells. Treatment with proton pump inhibitors (PPI) induces sensitization of cancer cells to chemotherapeutics via modifications of cellular pH gradients. It is also known that low pH is the most suitable condition for a full PPI activation. Here, we tested whether PPI treatment in unbuffered culture conditions could affect survival and proliferation of human B-cell tumors. First, we showed that PPI treatment increased the sensitivity to vinblastine of a pre-B acute lymphoblastic leukemia (ALL) cell line. PPI, per se, induced a dose-dependent inhibition of proliferation of tumor B cells, which was associated with a dose- and time-dependent apoptotic-like cytotoxicity in B-cell lines and leukemic cells from patients with pre-B ALL. The effect of PPI was mediated by a very early production of reactive oxygen species (ROS), that preceded alkalinization of lysosomal pH, lysosomal membrane permeabilization, and cytosol acidification, suggesting an early destabilization of the acidic vesicular compartment. Lysosomal alterations were followed by mitochondrial membrane depolarization, release of cytochrome c, chromatin condensation, and caspase activation. However, inhibition of caspase activity did not affect PPI-induced cell death, whereas specific inhibition of ROS by an antioxidant (N-acetylcysteine) significantly delayed cell death and protected both lysosomal and mitochondrial membranes. The proapoptotic activity of PPI was consistent with a clear inhibition of tumor growth following PPI treatment of B-cell lymphoma in severe combined immunodeficient mice. This study further supports the importance of acidity and pH gradients in tumor cell homeostasis and suggests new therapeutic approaches for human B-cell tumors based on PPI.

Follow-up care for childhood cancer survivors: A focus group analysis

Follow-up of survivors of childhood cancer is recommended to improve detection of late-effects, and provide individuals with information and advice. This study aimed to follow-up survivors of childhood cancer and report on their attitudes to current follow-up methods. Twenty-six survivors (13-25 years) of childhood cancer and their parent(s) attended focus groups (n = 7) to discuss views about follow-up care. Transcripts were analysed using interpretative phenomenological analysis (IPA). Three themes were identified: strategies to achieve a normal life (through playing down possibility of late-effects or careful monitoring of health); expectations about follow-up (facts and information, advice about self-care, everyday living, and psychosocial consequences) and preferences for different models of care. Given that some families had reservations about the benefits of follow-up, it is important that services address survivors' interests and meet their expectations. Changes to service delivery must take account of individual needs and expectations. Possible limitations of focus group methods (recruitment, bias reduction, methods of analysis and influence of other participants' views) are discussed.

Mothers' attitudes to the randomized controlled trial (RCT): the case of acute lymphoblastic leukaemia (ALL) in children

OBJECTIVES

Survival rates for childhood cancer have improved substantially partly as a result of national and international randomized clinical trials (RCT). However, the decision for families is complex and emotional. Our aim was to describe the views of mothers of children newly diagnosed with ALL regarding consent to randomized controlled trials.

DESIGN

Qualitative interview to explore mothers knowledge, and reasons for involving their child in RCTs. Interviews took place in mothers' homes.

PARTICIPANTS

Fifty mothers of children with newly diagnosed ALL (age 4-16 years; mean = 7.4) recruited through research nurses at outpatient appointments.

RESULTS

All but three families had consented for their child to be treated in the RCT, although there was wide variation in their understanding of the aims, costs and benefits. Most mothers reported the aim of the trial to compare 'old' and 'new' treatments.

CONCLUSION

Despite detailed verbal and written information, mothers were poorly informed about the purpose of the trial, and possibility of side effects. Individual preferences for either standard or new treatment were routinely reported. The data raise questions about the extent to which families give truly informed consent to recruitment of their child to an RCT.

Health-related quality of life of mothers of children with leukemia in Japan

OBJECTIVE

The study compared the health-related quality of life (HRQOL) of Japanese mothers of children with leukemia to that of mothers of children without leukemia.

METHOD

We used the Medical Outcomes Study 36-item Short-Form (SF-36) to measure the HRQOL of 97 mothers of children (average age 6.2, range 0-14) with leukemia diagnosed between 1999 and 2000, and compared their scores to those of 240 mothers of children without leukemia matched to the children with leukemia.

MAIN RESULTS

Of the eight unadjusted domain scores of the SF-36, five were significantly low among mothers of children with leukemia compared to mothers of children without leukemia: 'role-physical functioning' (RP), 'general health perception' (GH), 'vitality' (VT), 'social functioning' (SF) and 'mental health' (MH). Their SF-36 domain scores, when adjusted for demographic and clinical factors were also significantly low in RP, GH, VT, SF, RE and MH. The MH and SF scores in mothers of children with leukemia requiring hospital care were, respectively, approximately 20 points (1 standard deviation (SD), p < 0.0001) and 30 points (1.5 SD, p < 0.0001) lower than that of mothers of children without leukemia.

CONCLUSION

Mothers of children with leukemia requiring hospital care have poor HRQOL, particularly with regard to mental health and social functioning, and are at a greater risk for depression. These results suggest that the current system for treating leukemic diseases of children in Japan should also include close monitoring of mothers' mental health, and provision of appropriate treatment and psycho-social support.

An improved HPLC method for the quantitation of 6-mercaptopurine and its metabolites in red blood cells

A procedure is described for the rapid determination of the intra-erythrocyte concentration of 6-mercaptopurine (6-MP) and its metabolites, 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurine (6-MMP). Erythrocytes (8 x 10(8) cells) in 350 microl Hanks solution containing 7.5 mg dithiothreitol were treated with 50 microl 70% perchloric acid. The precipitate was removed by centrifugation (13,000 g) and the supernatant hydrolyzed at 100 degrees C for 45 min. After cooling, 100 microl was analyzed directly by HPLC using a Radialpack Resolve C18 column eluted with methanol-water (7.5:92.5, v/v) containing 100 mM triethylamine. 6-TG, 6-MP and the hydrolysis product of 6-MMP, 4-amino-5-(methylthio)carbonyl imidazole, were monitored at 342, 322 and 303 nm using a Shimadzu SPD-M10A diode array UV detector. The analytes eluted at 5.3, 6.0 and 10.2 min, respectively. The calibration curves were linear (r(2) > 0.998), and the analytical recoveries were 73.2% for 6-TG, 119.1% for 6-MP and 97.4% for 6-MMP. The intra- and inter-assay variations were highest for 6-MP (9.6 and 14.3%, respectively). The lowest detectable concentrations were 3, 3 and 25 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The quantification limits (coefficients of variation <15%) were 8, 10 and 70 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The method was applied to the analysis of 183 samples from 36 children under chemotherapy for acute lymphoblastic leukemia. The concentrations of the metabolites in the red cells of the patients ranged from 0 to 1934 pmol/8 x 10(8) erythrocytes for 6-TGN, and from 0 to 105.8 and 0 to 45.9 nmol/8 x 10(8) erythrocytes for 6-MP and 6-MMP, respectively. The procedure gave results that were in agreement with those obtained with other methods designed to detect cases of non-compliance with treatment, including patient interviews and medical evaluation, among others, demonstrating its applicability to monitoring the treatment of leukemic children.

The childhood leukemias

Advances in treatment and prognosis of childhood leukemia are considered a remarkable success of modern medicine. Childhood leukemia, once considered a universally fatal disease, now boasts overall cure rates ranging from 75% to 85% for acute lymphocytic leukemia (ALL) and cure rates approaching 40% to 50% for acute myelogenous leukemia (AML). Inherent to this success is the expertise nurses provide when caring for children with leukemia. Understanding the classifications of leukemia and the specific therapies help direct the specialized care children with leukemia need. This article provides an overview of childhood leukemias, diagnostic and classification methods used to differentiate and evaluate childhood leukemias, and treatment strategies applied toward various forms of childhood leukemias.

Pharmacogenetic screening and therapeutic drugs

BACKGROUND

Pharmacogenetics is the science of the influence of heredity on pharmacological response.

ISSUES

The cost of severe adverse drug reactions in individuals has been estimated in the US alone to be in excess of US$4 billion. It has been argued that in a significant proportion of cases, the efficacy and toxicity profiles of drug therapy would be substantially improved in individuals if characteristics due to genetic variation were taken into account. Methods are now available, which make screening for susceptibility feasible.

CONCLUSIONS

There are several therapeutic areas in which screening may give rise to significant improvements in outcome with cost-benefits to both the individual and the community. However, there is currently a lack of data on which cost-benefit analysis can be based. The challenge is to provide this information for new drugs, and for drugs with established therapeutic roles.

Low relapse rate in children with acute lymphoblastic leukemia after risk-directed therapy

PURPOSE

Even though acute lymphoblastic leukemia (ALL) responds well to chemotherapy, relapse remains the major problem. This study documents relapse and survival rates in 85 consecutive children (33 at good risk, 52 at high risk) with ALL diagnosed in 1991 to 1996.

PATIENTS AND METHODS

Until 1993, the New York II protocol for the high-risk group and a combination of UKALL XI (induction) and R blocks of ALL-REZ BFM-87 (intensification) regimens for patients at good risk were used. To reduce toxicity, the protocols were subsequently modified. Consolidation treatment was the same for both groups, consisting of a lower cytarabine dose and methotrexate removal, whereas intensification was changed only for the high-risk group using the BB block of the NHL-BFM-90 protocol. The bone marrow clearance of leukemia was assessed on day 22, and minimal residual disease was detected using polymerase chain reaction analysis of Ig heavy-chain gene rearrangements.

RESULTS

Seventy patients had common precursor B lineage ALL, six had pre-B-ALL, eight had T-ALL, and one had B-ALL. Two patients never achieved remission and died. Six patients died of consolidation-related complications. Four more patients died, two during induction and two during maintenance therapy. Two other children had relapse (2.3%), both of whom were treated with the earlier protocols and then underwent bone marrow transplantation. Four more children with morphologically complete remission showed minimal residual disease (which reached the levels of 1 leukemic cell among 10(2)-10(4) normal cells) with the use of clone-specific probes at several points of the study intervals, but never had relapse. The 5-year overall and event-free survival rates were 86% and 83%, respectively. The 5-year overall survival rates for good-risk and high-risk groups were 94% and 81%; the corresponding event-free rates were 91% and 78%. The 5-year event-free survival rate in the patients at high risk was significantly higher after the protocol change (90% vs. 65%, P = 0.04).

CONCLUSIONS

The modification proved to be effective in diminishing the therapeutic toxicity and improving the efficacy, mainly for the high-risk group.

Long-term persistence of symptoms

OBJECTIVES

To provide a brief review of cognitive changes, fatigue, lymphedema, and peripheral neuropathy as persistent symptoms, and provide assessment and management information.

DATA SOURCES

Published articles and research studies.

CONCLUSIONS

As the number of people surviving cancer for extended periods of time continues to increase, the phenomenon of symptoms that persist following the completion of treatment is being recognized.

IMPLICATIONS FOR NURSING PRACTICE

Research is needed to provide adequate knowledge about symptoms that persist following cancer treatment.

Recent advances in cystic fibrosis

The median life expectancy for cystic fibrosis is now over 30 years, and it is projected that in newborn infants it will become more than 40 years. The identification of the cystic fibrosis gene and its product, cystic fibrosis transmembrane conductance regulator (CFTR), has widened the spectrum of the disease from the classical case of the infant with cystic fibrosis to the elderly childless man with unexplained bronchiectasis. There is increasing evidence of the advantages of newborn screening for cystic fibrosis and subsequent specialist care. Management concentrates on optimising nutritional status and preventing lung infection and inflammation.

Childhood leukaemia: the medical cost of cure

More than 1 in every 1,500 individuals in the UK between 16 and 44 years of age has survived childhood cancer. This article describes the medical cost of cure in survivors of acute leukaemia, the most common form of childhood cancer.