Survival of childhood acute lymphoblastic leukemia: results of therapy at Tata Memorial Hospital, Bombay, India

Precursor B-cell acute lymphoblastic leukaemia-a global view

As haematologists, we always seek to follow standardised guidelines for practice and apply the best treatment within our means for our patients with blood diseases. However, treatment can never follow an exact recipe. Opinions differ as to the best approach; sometimes more than one treatment approach results in identical outcomes, or treatments differ only by the manner in which they fail. Furthermore, the haematologist is faced with constraints relating to the local economic environment. Patients too are not the same the world over. Early presentation is commoner in the developed world, as is the patient’s understanding of the disease process. This in turn has an impact on the way patients are managed, the rigorousness of patient adhesion to the treatment schedule and the outcome. Here we take a look at the precursor B‐cell acute lymphoblastic leukaemia in an adolescent in a range of different settings from low‐ to high income countries with widely differing challenges for diagnosis, therpy and follow‐up. For these reasons, given the same starting conditions, patients will be treated differently according to the institute and the country they are in. Experts from around the world have been tasked to describe their management plan and rationale for a specific disease presentation. Here they explore the management of precursor B‐cell acute lymphoblastic leukaemia (pre‐B ALL) in five different institutions worldwide with a focus on those with more or less strained economies. We end with a conclusion from an expert in the field comparing and contrasting these different management styles and considering their merits and limitations.

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.

Hyperleukocytosis: emergency management

Hyperleukocytosis is defined as peripheral blood leukocyte count exceeding 100,000/mm(3). Acute leukemia is the most common etiology in pediatric practice. Hyperleukocytosis is a medical emergency. The increased blood viscosity, secondary to high white cell count and leukocyte aggregates, results in stasis in the smaller blood vessels. This predisposes to neurological, pulmonary or gastrointestinal complications. In addition, patients are at risk for tumor lysis syndrome due to the increased tumor burden. Initial management includes aggressive hydration, prevention of tumor lysis syndrome, and correction of metabolic abnormalities. A red cell transfusion is not indicated in a hemodynamically stable child, as it adversely affects the blood viscosity. Leukapheresis is the treatment of choice for a very high count, or in patients with symptomatic hyperleukocytosis. The technical expertise required, a relative difficult venous access in younger children, risk of anticoagulation and possible non-availability of the procedure in emergency hours are limitations of leukapheresis. However, it is a rewarding procedure and performed with relative ease in centers that perform the procedure frequently. An exchange transfusion is often a practical option when hyperleukocytosis is complicated with severe anemia. The partial exchange aids in correcting both, without the risk of volume overload or hyperviscosity, which are the limitations of hydration and blood transfusion, respectively. Etiology and management of hyperleukocytosis in relevance to the pediatric emergency room is outlined.

Successful outcome in a HIV infected child presenting with Pre-B Acute Lymphoblastic Leukemia

The present case is a 5 y old child with Pre-B Acute Lymphoblastic Leukemia (ALL), presenting with fever, pallor, purpuric spots, hepato-splenomegaly and lymphadenopathy of 20 d duration. During re-induction chemotherapy, he developed atypical skin lesions diagnosed as Varicella Zoster infection. He and his parents tested positive for anti HIV antibody. He entered complete remission and Anti-retroviral therapy (ART) along with maintenance chemotherapy has been initiated 3 mon ago. Acute leukemia is rare in HIV and probably this is the first case of Pre-B Acute Leukemia in association with perinatally transmitted HIV.

Survival outcome of childhood acute lymphoblastic leukemia in India: a resource-limited perspective of more than 40 years

The outcome of childhood acute lymphoblastic leukemia in India has been inferior to more than 80% cure rates in developed nations. This study was done to analyze the outcome of acute lymphoblastic leukemia in India over 4 decades. There has been a gradual improvement in survival rates of up to >70% in some centers along with a decline in relapse and mortality. However, these results cannot be generalized to the entire nation. There is a crying need to address treatment abandonment, take quality improvement, educational and financial initiatives; cooperative research into risk factors and disease biology, and the implementation of risk stratification along with the assessment of response to therapy.

Overt testicular disease at diagnosis in childhood acute lymphoblastic leukemia: prognostic significance and role of testicular irradiation

OBJECTIVE

To analyze the prognostic impact of overt testicular disease (OTD) at diagnosis and role of testicular irradiation in the same.

METHODS

Data of 579 boys treated at our center over 16 years was reviewed.

RESULTS

Fourteen (2.4%) males had OTD. 10 (71.4%) of these had high-risk disease. Patients with OTD, had a significantly higher incidence of mediastinal-adenopathy (p=0.001), hyperleucocytosis (p=0.004) and CNS disease at presentation (p<0.0001) compared to patients in continuous complete remission (CCR). 4 of the 11 patients with OTD, who opted for therapy, had relapse; 2 are in CCR. Although, survival in patients with OTD was inferior (p=0.183) compared to patients without OTD, it was not an independent prognostic factor (p=0.47). In the entire study cohort, symptom-diagnosis interval (p=0.006), white cell (p=0.001) and platelet count (p=0.001) at presentation were significantly associated with survival (Cox multivariate regression analysis).

CONCLUSIONS

OTD was not an independent prognostic factor, despite association with high-risk features. Survival outcome was inferior. The observations indicate the need of revaluation of the present protocol with incorporation of intermediate dose and subsequently high-dose methotrexate (after assessment for toxicity and tolerance), risk-stratified therapy and plausibly omission of testicular irradiation.

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.

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.

Treatment of acute lymphoblastic leukaemia in countries with limited resources; lessons from use of a single protocol in India over a twenty year peroid

In the 1970s, survival rates after treatment for acute lymphoblastic leukaemia (ALL) in children and young adults (less than 25 years) in India were poor, even in specialised cancer centres. The introduction of a standard treatment protocol (MCP841) and improvements in supportive care in three major cancer centres in India led to an increase in the event-free survival rate (EFS) from less than 20% to 45-60% at 4 years. Results of treatment with protocol MCP841 between 1984 and 1990 have been published and are briefly reviewed here. In addition, previously unpublished data from 1048 patients treated between 1990 and 1997 are reported. Significant differences in both patient populations and treatment outcome were noted among the centres. In one centre, a sufficiently large number of patients were treated each year to perform an analysis of patient characteristics and outcome over time. Although steady improvement in outcome was observed, differences in the patient populations in the time periods examined were also noted. Remarkably, prognostic factors common to all three centres could not be defined. Total white blood cell count (WBC) was the only statistically significant risk factor identified in multivariate analyses in two of the centres. Age is strongly associated with outcome in Western series, but was not a risk factor for EFS in any of the centres. Comparison of patient characteristics with published series from Western nations indicated that patients from all three Indian centres had more extensive disease at presentation, as measured by WBC, lymphadenopathy and organomegaly. The proportions of ALLs with precursor T-cell immunophenotypes, particularly in Chennai, were also increased, even when differences in the age distribution were taken into consideration (in <18-year olds, the range was 21.1-42.7%), and in molecular analyses performed on leukaemic cells from over 250 patients less than 21-years-old with precursor B-cell ALL, a lower frequency of TEL-AML1-positive ALL cases than reported in Western series was observed. The worse outcome of treatment in Indian patients compared with recent Western series was probably due to the higher rate of toxic deaths in the Indian patients, and possibly also due to their more extensive disease - which is, at least partly, a consequence of delay in diagnosis. Differences in the spectrum of molecular subtypes may also have played a role. The higher toxic death rates observed are likely to have arisen from a combination of more extensive disease at diagnosis, co-morbidities (e.g., intercurrent infections), differences in the level of hygiene achievable in the average home, poor access to acute care, and more limited supportive care facilities in Indian hospitals. Toxic death was not associated with WBC at presentation, and hence would tend to obscure the importance of this, and, potentially, other risk factors, as prognostic indicators. Since the prevalence of individual risk factors varies in different populations and over time, their relative importance would also be expected to vary in different centres and in different time periods. This was, in fact, observed. These findings have important implications for the treatment of ALL in countries of low socioeconomic status; it cannot be assumed that risk factors defined in Western populations are equally appropriate for patient assignment to risk-adapted therapy groups in less affluent countries. They also demonstrate that heterogeneity in patient populations and resources can result in significant differences in outcome, even when the same treatment protocol is used. This is often overlooked when comparing published patient series.