there has been a dramatic improvement in the survival outcome of acute lymphoblastic leukemia ( all ) patients with a better understanding of molecular biology , the use of combination chemotherapy protocols , risk stratification using clinical , genetic , and molecular parameters , improvements in supportive care , along with effective central nervous system ( cns ) prophylaxis .
mcp 841 protocol has emerged to be an effective tool with tolerable toxicities and thus , is useful even for developing countries .
bfm 90 , bfm-95 , and ukall - xi protocols are widely used in western countries but rarely used in limited resource settings due to their higher toxicities .. survival outcome in childhood all has reached over 80% in resource - rich nations .
however , reports from various institutions in india suggest that the outcome is inferior to that achieved in the developed nations due to poor management of infections , leading to toxic deaths and also increased incidence of relapse .
the patient population of india differs markedly from the western population with respect to the prevalence of illiteracy , poverty , malnutrition , and chronic infectious diseases .
although multiple studies have been performed across the world ; there is a deficiency of data available on the prognostic factors , response to treatment , and research on the biology of all from the northwest indian perspective .
our institute , being a regional cancer center , treats a significant proportion of all patients who are provided with the best possible treatment within resource and financial constraints .
we present the findings of a retrospective study designed to estimate the relapse - free survival of all patients treated uniformly with mcp 841 protocol on the basis of various prognostic factors .
the identification of prognostic factors and toxicities would help to determine the management lacunae and would lead to an overall improvement in the quality of care of all patients .
a total of 310 previously untreated all patients from northwest india presenting to our oncology outpatient department ( opd ) from june 2002 to june 2008 who took treatment and were on regular follow - up for 5 years were selected in this retrospective hospital - based study .
diagnosis of all was confirmed by bone marrow ( bm ) aspiration on the first visit .
detailed clinical history , physical examination , peripheral blood film ( pbf ) , and biochemical profiles , including liver and renal function tests , were performed at the initial presentation .
cerebrospinal fluid ( csf ) was obtained for cytology in patients suspected of cns disease at presentation .
csf - positive patients and those having l3 ( french - american - british criteria ) were not included in this study .
the mcp 841 protocol , first used in india , includes effective drugs given in such a way that the minimal supportive care is required ; this factor is the main reason for the reduction in costs .
the approximate cost of complete course of treatment with mcp 841 protocol in the indian setting is about 3000 usd ( 2,00,000 inr ) ; however , the cost is highly dependent on the costs of hospital admission and transfusion . in our regional cancer center , these costs were minimal because of funding by the government . apart from this ,
most of the chemotherapy drugs were provided free of cost , further cutting the costs and making the treatment available within the reach of poor families .
data were obtained from the records of these 310 carefully selected patients and were analyzed .
ethical approval was not required for this study as the study was retrospective and the patients who were selected were treated with a standard institutional protocol . immunophenotyping ( ipt )
was performed in 205 patients who could afford it out of 310 cases using a panel of monoclonal antibodies , which included cd2 , 4 , 5 , 7 , 8 , 10 , 11b , 15 , 19 , 20 , 36 , 13 , 33 , hla - dr , and surface immunoglobulin ( sig ) .
t - cell all was defined as either cd5- or cd7-positive with or without additional t - cell markers but with negative b - cell antigens .
the patient 's guardians were counseled regarding the need for strict adherence to the protocol and need for timely follow - up .
patients received two induction cycles ( i1 and i2 ) , repeat induction ( ri1 ) , consolidation ( c ) , and six maintenance cycles ( m ) .
cns prophylactic therapy included cranial irradiation ( 2,000 cgy ) for children above the a1ge of 3 years .
patients less than 3 years were treated with an alternative regimen ( i2a ) containing high dose cytarabine with granulocyte colony - stimulating factor ( g - csf ) support .
all patients received 12 weekly intrathecal injections of methotrexate during the induction and consolidation phases of therapy in a dose of 8 mg , 10 mg , and 12 mg in children under 2 years , 2 - 3 years , and more than 3 years of age , respectively .
table showing the mcp841 protocol with the various phases , along with the drugs used with their doses the patients were hospitalized in the leukemia ward of our hospital to start the induction protocol .
complete blood count ( cbc ) was performed biweekly ( thrice weekly if the patient had thrombocytopenia ) and pbf was performed weekly .
csf examination was performed monthly during the induction and consolidation phases to detect early cns relapse . during the maintenance phase
complete remission ( cr ) was defined as less than 5% lymphoblasts in a normocellular bm in the absence of clinical evidence of disease .
patients with more than 5% blasts at the end of induction regimen were considered as nonresponders .
relapse was defined as the presence of unequivocal malignant blast cells ( > 25% ) in the bm or on histological or cytological documentation of blasts in extramedullary sites after the achievement of cr .
the relapses were classified on the basis of the sites of relapses , that is , bm , cns , and testi(e)s .
csf was examined in patients presenting with headache and vomiting . in case of bone marrow relapse , clinical examination of testes and
a csf study were mandatory to rule out concurrent testis and cns disease , respectively . in cases with nontender testicular enlargement , fine - needle aspiration cytology ( fnac )
the presence of unequivocal blasts in csf irrespective of csf cell count and/or new onset cranial nerve palsy was considered as cns leukemia . at the start of the protocol ,
the patients relatives were counseled to deposit blood in our hospital 's blood bank in advance for the timely management of hematological complications .
patients with high total leukocyte count ( tlc ) were prescribed allopurinol 100 - 600 mgm in two to three divided doses for the prevention of uric acid nephropathy .
serum electrolytes were monitored in such patients due to the high risk of tumor lysis syndrome .
povidone iodine gargle was given to maintain good oral hygiene and clotrimazole lozenges were used for prophylaxis of fungal infections .
after sending blood for culture and sensitivity , empirical choice was ceftazidime / ceftriaxone with amikacin .
the addition of fluconazole was considered if fever persisted for more than 72 h after starting iv antibiotics .
blood transfusions were given if the hemoglobin level was below 8 g / dl and platelets when the count was below 20,000/cmm or in the presence of bleeding .
the 5-year relapse - free survival was calculated on the basis of b - cell versus t - cell all , tlc at presentation > 1 lakh / cmm , age at presentation , sex , common acute lymphoblastic leukemia antigen ( calla ) positivity , the presence of blasts in pbf on day 15 of induction , and completion of protocol within prescribed time .
meir survival curves were plotted and log - rank ( mantel  cox ) test was performed for the comparison of survival curves ; statistical significance ( p value ) and chi - square values were calculated . the mean survival with 95% confidence interval ( ci )
assuming the proportional hazards assumption to be true in this calculation , cox regression analysis was performed by forward stepwise ( likelihood ratio ) method and hazard ratio with 95% ci was also obtained .
all statistical calculations were performed using statistical package for the social sciences ( spss ) software for windows version 20.0 ( ibm corp . ,
patients received two induction cycles ( i1 and i2 ) , repeat induction ( ri1 ) , consolidation ( c ) , and six maintenance cycles ( m ) .
cns prophylactic therapy included cranial irradiation ( 2,000 cgy ) for children above the a1ge of 3 years .
patients less than 3 years were treated with an alternative regimen ( i2a ) containing high dose cytarabine with granulocyte colony - stimulating factor ( g - csf ) support .
all patients received 12 weekly intrathecal injections of methotrexate during the induction and consolidation phases of therapy in a dose of 8 mg , 10 mg , and 12 mg in children under 2 years , 2 - 3 years , and more than 3 years of age , respectively .
table showing the mcp841 protocol with the various phases , along with the drugs used with their doses the patients were hospitalized in the leukemia ward of our hospital to start the induction protocol .
complete blood count ( cbc ) was performed biweekly ( thrice weekly if the patient had thrombocytopenia ) and pbf was performed weekly .
csf examination was performed monthly during the induction and consolidation phases to detect early cns relapse . during the maintenance phase
complete remission ( cr ) was defined as less than 5% lymphoblasts in a normocellular bm in the absence of clinical evidence of disease .
patients with more than 5% blasts at the end of induction regimen were considered as nonresponders .
relapse was defined as the presence of unequivocal malignant blast cells ( > 25% ) in the bm or on histological or cytological documentation of blasts in extramedullary sites after the achievement of cr .
the relapses were classified on the basis of the sites of relapses , that is , bm , cns , and testi(e)s .
csf was examined in patients presenting with headache and vomiting . in case of bone marrow relapse , clinical examination of testes and
a csf study were mandatory to rule out concurrent testis and cns disease , respectively . in cases with nontender testicular enlargement , fine - needle aspiration cytology ( fnac )
the presence of unequivocal blasts in csf irrespective of csf cell count and/or new onset cranial nerve palsy was considered as cns leukemia .
at the start of the protocol , the patients relatives were counseled to deposit blood in our hospital 's blood bank in advance for the timely management of hematological complications .
patients with high total leukocyte count ( tlc ) were prescribed allopurinol 100 - 600 mgm in two to three divided doses for the prevention of uric acid nephropathy .
patients with tlc > 1 lakh / cmm received intravenous ( iv ) hydration 4 l / sqm , along with the injection sodium bicarbonate .
serum electrolytes were monitored in such patients due to the high risk of tumor lysis syndrome .
povidone iodine gargle was given to maintain good oral hygiene and clotrimazole lozenges were used for prophylaxis of fungal infections .
febrile neutropenic patients were treated with iv antibiotics . after sending blood for culture and sensitivity ,
the addition of fluconazole was considered if fever persisted for more than 72 h after starting iv antibiotics .
blood transfusions were given if the hemoglobin level was below 8 g / dl and platelets when the count was below 20,000/cmm or in the presence of bleeding .
the 5-year relapse - free survival was calculated on the basis of b - cell versus t - cell all , tlc at presentation > 1 lakh / cmm , age at presentation , sex , common acute lymphoblastic leukemia antigen ( calla ) positivity , the presence of blasts in pbf on day 15 of induction , and completion of protocol within prescribed time .
meir survival curves were plotted and log - rank ( mantel  cox ) test was performed for the comparison of survival curves ; statistical significance ( p value ) and chi - square values were calculated . the mean survival with 95% confidence interval ( ci )
assuming the proportional hazards assumption to be true in this calculation , cox regression analysis was performed by forward stepwise ( likelihood ratio ) method and hazard ratio with 95% ci was also obtained .
all statistical calculations were performed using statistical package for the social sciences ( spss ) software for windows version 20.0 ( ibm corp . , armonk
the characteristics of patients at presentation are depicted in table 2 . out of 310 patients , 215 ( 69% ) were males , with the male / female ratio being 2.2:1 .
one hundred and sixty five ( 53.2% ) patients were in remission at the end of 5 years of the starting of treatment .
a total of 126 patients ( 40.6% ) relapsed in 5 years from the start of the treatment .
most of these relapses ( n = 113 , 89.6% ) occurred while the patients were on treatment . table 3 shows the timing of relapse of these patients .
the most frequent site of relapse was bm ( n = 114 , 90.4% ) followed by cns ( n = 7 , 5.5% ) , testis ( n = 3 , 2.4% ) , and solitary bone ( n = 2 , 1.6% ) .
thus , bm , cns , and testicular relapse rates were found in 39.1% , ( n = 114 of 291 ) , 2.4% ( n = 7 of 291 ) , and 1% ( n = 3 of 291 ) of the patients , respectively .
table showing baseline characteristics of patients with reference to demographic and hematologic parameters table showing the number of relapses as per the phase of treatment overall , the 5-year survival was 53.2% .
meir analysis for b - cell all was 62% while for t cell it was 28% ( p
the mean survival for b and t lineages was 39.35 months and 26.38 months , respectively [ hazards ratio ( hr ) 1.41 , 95% ci 1.19 - 1.63 , p 0.002 ] .
table 4 summarizes the results of statistical tests for survival analysis for various subgroups . in patients with day 15
pbf without blast , relapse - free survival was 65% while in those with persistent blast , it was 45% ( p
1 lakh at presentation , relapse - free survival was 68% and in those with tlc > 1 lakh had 41% survival with a mean survival of 42.51 months and 30.99 months , respectively ( hr 2.14 , 95% ci 1.76 - 2.48 , p < 0.001 ) [ figure 2 ] .
calla - positive patients had 95% survival while calla - negative patients had only 20% survival ( hr 2.46 , 95% ci 1.48 - 4.09 , p < 0.001 ) .
for the <3 years age group , survival was 30% ( hr 2.90 with reference to 3 - 10 years age group , 95% ci 1.55 - 5.44 , p < 0.001 ) , for the > 20 years age group it was 15% , for the 3 - 10 years age group and 1115 years age group it was 65% and 64% , respectively , while for the 16 - 20 years age group , it was 59% ( p < 0.001 , ) [ figure 3 ] .
the mean survival time for <3 years age group was 21.34 months , for 3 - 10 years , 11 - 15 years , and 16 - 20 years , it was 41.59 months , 40.82 months , and 40.20 months , respectively , while for > 20 years , it was 18.34 months ( hr 3.39 , 95% ci 2.09 - 5.51 , p < 0.001 )
. however , the data were not statistically significant for males ( 50% ) versus females ( 60% ) ( p 0.24 ) .
meier survival plot showing 5-year relapse - free survival probability for t - cell all and b - cell all table showing survival estimates ( kaplan  meier and cox regression ) according to various prognostic variables survival plot showing 5-year relapse - free survival probability with total leukocyte count ( tlc ) at presentation against time kaplan  meier plot showing agewise 5-year relapse - free survival probability plotted against time
the last few decades have seen the use of modern combination chemotherapy protocols with highly effective cns prophylaxis . despite these developments ,
the prognosis of all patients remains poor in developing counties due to the lack of resources and delay in diagnosis . also , there are reports suggestive of a different biology of all in india as compared to the western world .
t - cell all is more frequent in india though the overall incidence of all is threefold lower in india as compared to the usa .
these differences in the biology of the disease are thought to affect both the disease extent and results of the treatment .
also , the third world countries are known for the prevalence of malnutrition and chronic infectious diseases .
these environmental factors are thought to adversely influence the tolerance to intensive combination chemotherapy regimens , leading to increased toxicity of the treatment .
this study was designed to address these issues with a target to improve the future management of all patients .
the authors would like to highlight the use of high dose cytarabine in children less than 3 years of age . a recent study by mirouliaei et al . showed that cranial radiotherapy of 18 - 24 gy in children suffering from all lead to growth hormone deficiency after clonidine stimulation test in 44% of the patients and in 50% of these cases , within 1 year of whole brain radiation .
it has been reported that somatotroph hormone axis is more sensitive to radiation in children than in adults .
follin et al . concluded that all survivors , treated with a moderate dose of prophylactic cranial radiotherapy , have a central adrenal insufficiency 20 years after diagnosis .
an increased awareness of the risk for an adrenal insufficiency is of importance and lifelong surveillance of the entire hypothalamic - pituitary axis is recommended in these patients .
these manifestations are more likely to occur if cranial radiotherapy is given to younger children in whom brain development is still in process .
thus , the institutional protocols of some leading cancer care centers in india are using high dose cytarabine ( i2a protocol ) as an alternative to cranial radiation in children <3 years of age .
an important feature of patient characteristics in our study is a definite male preponderance ( m : f = 2.2:1 ) .
however , in an indian study by arya et al . , this ratio was 3.6:1 .
these data strongly reflect the poor care of female children in india and the preferential treatment of male siblings . another important difference , which deserves to be highlighted is tlc at presentation . in our study
this is in clearly a great excess when compared with both indian and western studies .
a possible explanation is that in most of these studies , only childhood all patients were enrolled while in our study , every all patient was enrolled irrespective of age .
also , since our center caters to a population living in highly remote areas that are far from proper health care facilities , there is high chance that patients presented late with an increased burden of the disease .
tlc at presentation proved to be a highly significant ( p < 0.001 ) prognostic factor for relapse - free survival .
some centers use i2a protocol ( high dose cytarabine ) in patients with high tlc counts ( > 1 lakh / cmm ) at presentation , apart from using it for eradicating blasts from cns in children <3 years .
it is associated with higher tlc at diagnosis , the male gender , older age , and mediastinal mass . also , these patients are at a higher risk of induction failure . in our study , the incidence of t - cell all was 19% .
( 20.7% ) . however , another indian study by arya et al . reported a 31% incidence of this phenotype .
these data clearly establish the difference in the biologies of all in india from the western world .
patients with persistent circulating leukemic cells at 7 - 10 days after the initiation of combination chemotherapy have been found to be at increased risk of relapse .
the rate of clearance of peripheral blasts has been found to be of prognostic significance in both t - cell and b lineage alls . in our study
, a strong positive correlation was noted between day 15 pbf without blast and relapse - free survival supporting its role as an important prognostic factor .
precursor b - cell all is defined by the expression of cytoplasmic cd79a , cd19 , hla dr , and other b cell - associated antigens .
b - cell alls express cd10 surface antigen ( known as common all antigen ; calla ) .
the absence of cd10 is associated with mll translocations , particularly t ( 4 ; 11 ) and a poor outcome .
calla - positive patients had a much better 5-year relapse - free survival than calla - negative patients in our study ( 95% versus 20% , hr 2.46 , p < 0.001 ) .
age at diagnosis has a strong prognostic significance , reflecting different underlying biologies of all in different age groups .
the better prognosis in young children ( 1 - 10 years ) is partially explained by the more frequent occurrence of favorable cytogenetic features in the leukemic blasts including hyperdiploidy with 51 or more chromosomes and/or favorable chromosome trisomies , or the etv6-runx1;t ( 12 ; 21 ) , also known as the tel - aml1 translocation .
this subgroup presents typically with very high tlc counts and an increased incidence of cns involvement , resulting in a poor overall survival .
our data showed the best 5-year relapse - free survival probability for 3 - 10 years age group ( 70% ) followed by 11 - 15 years and 16 - 20 years age groups .
those <3 years and > 20 years had poorer survival probability ( 15 - 30% ) .
cns relapse was observed in 2.4% of the patients who achieved remission . in an indian study by raje et al .
the overall 5-year survival in our study was 53.2% , which was clearly lesser than not only western but also other indian studies .
this could be attributed to the higher incidence of high - risk disease and differences in tumor biology in the northwest indian scenario .
the mcp 841 protocol is an important landmark in the advancement of treatment and outcomes of childhood all in india .
however , this protocol has some drawbacks , one of the biggest being that there is no risk stratification to either intensify or deintensify treatment .
the study being a retrospective one , suffers from the usual drawback of the availability of limited data in the records of a busy cancer center .
although cytogenetics and reverse transcription polymerase chain reaction ( rt - pcr ) tests are being now routinely performed in all patients , they were sparingly done few years back at our center . also , ipt reports entry in the records were limited , thereby restricting our analysis to b - cell versus t - cell and calla - positive versus calla - negative patients .
hence , it was not possible to find out the detailed correlation seen between outcome and these reports .
the study being a retrospective one , suffers from the usual drawback of the availability of limited data in the records of a busy cancer center .
although cytogenetics and reverse transcription polymerase chain reaction ( rt - pcr ) tests are being now routinely performed in all patients , they were sparingly done few years back at our center . also , ipt reports entry in the records were limited , thereby restricting our analysis to b - cell versus t - cell and calla - positive versus calla - negative patients .
hence , it was not possible to find out the detailed correlation seen between outcome and these reports .
the data presented in this study clearly indicate the need of more aggressive treatment and more research on the biology of all in the indian setting . the greater distance of dedicated cancer centers , apart from ignorance , illiteracy , poverty , and belief in an alternate system of medicine can be implicated as the root causes of poor prognosis of all in india .
mcp 841 protocol is a useful tool for treatment of all in children when more aggressive protocols can not be used .
akap collected data , wrote the paper , performed statistical analysis and reviewed the literature .
 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 . 
INTRODUCTION
MATERIALS AND METHODS
Treatment protocol
Supportive care
Statistical analysis
RESULTS
DISCUSSION
Drawbacks of the study
CONCLUSIONS
Financial support and sponsorship
Conflicts of interest
AUTHOR'S CONTRIBUTION