Leukemia (2010) 24, & 2010 Macmillan Publishers Limited All rights reserved /10 $

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1 EDUCATIONAL REPORT (2010) 24, & 2010 Macmillan Publishers Limited All rights reserved /10 $ Long-term results of the Italian Association of Pediatric Hematology and Oncology (AIEOP) Studies 82, 87, 88, 91 and 95 for childhood acute lymphoblastic leukemia V Conter 1,2, M Aricò 3, G Basso 4, A Biondi 1, E Barisone 5, C Messina 4, R Parasole 6, G De Rossi 7, F Locatelli 8, A Pession 9, N Santoro 10, C Micalizzi 11, M Citterio 1, C Rizzari 1, D Silvestri 1, R Rondelli 9, L Lo Nigro 12, O Ziino 13, AM Testi 14, G Masera 1, MG Valsecchi 15 for the Associazione Italiana di Ematologia ed Oncologia Pediatrica (AIEOP) 1 Department of Pediatrics, University of Milano-Bicocca, Ospedale S. Gerardo, Monza, Italy; 2 Department of Pediatrics, Ospedali Riuniti, Bergamo, Italy; 3 Department of Pediatrics, Ospedale Meyer, Firenze, Italy; 4 Department of Pediatrics, Ospedale Policlinico, University of Padova, Padova, Italy; 5 Department of Pediatrics, Ospedale Infantile Regina Margherita, University of Torino, Torino, Italy; 6 Department of Pediatrics, Ospedale Pausillipon, Napoli, Italy; 7 Department of Pediatrics, Ospedale Bambin Gesù, Roma, Italy; 8 Department of Pediatrics, Policlinico San Matteo, University of Pavia, Pavia, Italy; 9 Department of Pediatrics, Policlinico Sant Orsola-Malpighi, University of Bologna, Bologna, Italy; 10 Department of Pediatrics, Ospedale Policlinico, University of Bari, Bari, Italy; 11 Department of Pediatrics, Ospedale Gaslini, Genova, Italy; 12 Department of Pediatrics, Clinica Pediatrica, University of Catania, Catania, Italy; 13 Department of Pediatrics, Ospedale dei Bambini G. di Cristina, Palermo, Italy; 14 Department of Hematology, University La Sapienza, Roma, Italy and 15 Medical Statistics Unit, Department of Clinical Medicine and Prevention, University of Milano-Bicocca, Monza, Italy We analyzed the long-term outcome of 4865 patients treated in Studies 82, 87, 88, 91 and 95 for childhood acute lymphoblastic leukemia (ALL) of the Italian Association of Pediatric Hematology and Oncology (AIEOP). Treatment was characterized by progressive intensification of systemic therapy and reduction of cranial radiotherapy. A progressive improvement of results with reduction of isolated central nervous system relapse rate was obtained. Ten-year event-free survival increased from 53% in Study 82 to 72% in Study 95, whereas survival improved from 64 to 82%. Since 1991, all patients were treated according to Berlin-Frankfurt-Muenster (BFM) ALL treatment strategy. In Study 91, reduced treatment intensity (25%) yielded inferior results, but intensification of maintenance with high-dose (HD)- L-asparaginase (randomized) allowed to compensate for this disadvantage; in high-risk patients (HR, 15%), substitution of intensive polychemotherapy blocks for conventional BFM backbone failed to improve results. A marked improvement of results was obtained in HR patients when conventional BFM therapy was intensified with three polychemotherapy blocks and double delayed intensification (Study 95). The introduction of minimal residual disease monitoring and evaluation of common randomized questions by AIEOP and BFM groups in the protocol AIEOP-BFM-ALL 2000 are expected to further ameliorate treatment of children with ALL. (2010) 24, ; doi: /leu ; published online 17 December 2009 Keywords: acute lymphoblastic leukemia; childhood; long-term results Introduction Over the past four decades, the Italian Association of Pediatric Hematology and Oncology (AIEOP) has used national chemotherapy protocols for treatment of childhood acute lymphoblastic leukemia (ALL), with a progressive improvement in networking and scientific activity In the earlier studies conducted in the 70s, all patients received a relatively low-intensity chemotherapy and cranial Correspondence: Dr V Conter, Clinica Pediatrica, Ospedale Nuovo S.Gerardo, via Pergolesi 33, Monza 20052, Italy. v.conter@hsgerardo.org Received 12 August 2009; accepted 11 September 2009; published online 17 December 2009 radiotherapy (CRT). In Study 82, patients were stratified into three risk groups. CRT was omitted in standard risk patients (SR, 12% of total). High-risk patients (HR, 25%) were treated with intensive, short duration chemotherapy without CRT; results obtained, however, were poor and, thus, a new protocol was adopted from 1985 for HR patients who received intermediate dose of methotrexate (MTX), CRT and protracted L-asparaginase (L-ASP) with clear benefit. This treatment strategy was continued in Study 87. In 1988, a new protocol (Study 88) was started as a pilot experience in selected AIEOP centers introducing intensive BFMtype chemotherapy derived from Berlin-Frankfurt-Muenster (BFM) ALL 86 Study. 14 Study 88 showed that BFM therapy was feasible in AIEOP centers. In Study 91, the early in vivo response to steroid pre-phase was used to discriminate prednisone good responders (PGR) from prednisone poor responders (PPR) (children with o or X1000/mm 3 blasts in the peripheral blood after 7 days of steroids and one injection of intrathecal MTX, IT-MTX, respectively) and was used to stratify patients in different groups of treatment; 15 preventive CRT was restricted to HR patients (B15%), in whom treatment intensification with nine blocks of therapy was introduced unsuccessfully. 6 For SR patients (25%), an intergroup Study was conducted (together with the Dutch Children Study Group and Hungarian Oncology Group): patients were randomized to receive or not to receive protracted high-dose (HD)-L-ASP. Intermediate risk (IR) patients did not receive CRT and, interestingly, results were dismal in patients with T-ALL and X /cmm WBC count. 16 In Study 95, only very low-risk patients (7% total) were treated in the SR arm. The large intermediate risk group of patients was randomized at the beginning of maintenance to receive or not to receive vincristine (VCR) þ dexamethasone (DXM) pulses. HR patients received the whole conventional BFM induction, followed by consolidation with only three intensive chemotherapy blocks as consolidation therapy, repeated reinduction therapy (BFM Protocol II 2) and maintenance with VCR/ prednisone (PDN) pulses. This treatment allowed to substantially improve the results in these patients. The aim of this paper is to summarize the therapeutic strategies and the long-term results of the ALL studies conducted

2 256 in the period by AIEOP. It provides 15-year updated figures for studies 82, 87, 88, 91 reported earlier in 13 and newly presents long-term results of Study 95. Patients and methods From 1982 through 2000, a total of 4865 consecutive patients younger than 18 years of age (age was restricted to o15 years until 1995) with newly diagnosed ALL were enrolled into five studies. The diagnosis was based on morphologic evaluation of bone marrow aspirates and negative staining for myeloperoxidase or Sudan Black. Complete immunophenotyping has been routinely evaluated by the reference central laboratory since For all studies, complete remission was defined as the absence of physical signs of leukemia or detectable leukemia cells on blood smears; a bone marrow with active hematopoiesis and fewer than 5% leukemia blast cells; and normal cerebrospinal fluid. Treatment Total duration of therapy was 24 months for all patients. Details of treatment have been reported in earlier publications. The strategy of each study is briefly summarized. Study 82. This study was open from August 1982 to February 1987, for patients aged 1 o15 years. SR and IR patients had a three-drug induction therapy; IR patients had CRT with 1800 cgy and reinduction therapy with VCR, daunorubicine (DNR) and PDN. HR patients were treated until 1985 with a sixdrug induction, followed by HD cytarabine and a four-drug reinduction phase; CRT was not used. Owing to poor results at interim analysis, this HR arm (8303) was closed in February 1985 and replaced by protocol 8503, which consisted of the IR group therapy intensified by the introduction of DNR as fourth drug in induction phase, intermediate dose MTX (0.5 g/m 2 3) and by 20 weekly HD-L-ASP, given during reinduction and continuation therapy. Continuation therapy was based on daily oral 6-mercaptopurine, weekly i.m. MTX and VCR/PDN pulses. 3 Study 87. The study was open to enrollment of ALL patients aged 1 o15 years from March 1987 to April Treatment schedule was largely based on the previous Study 82, with the following treatment modifications: (a) DNR during induction therapy and a three-drug reinduction therapy were given also to non-hr patients; (b) IT-MTX (three doses) was administered in both IR and HR patients during CRT. 4 Study 88. From February 1988 to March 1992, AIEOP conducted another ALL study, largely contemporary to the Study 87, based on the BFM-ALL 86 Study 14 and restricted to 10 AIEOP centers. All patients received the entire Protocol I as induction therapy and HD-MTX (5 g/m 2 4); reinduction therapy consisted of Protocol III for SR patients or Protocol II for IR/HR patients. Protracted IT therapy during maintenance was given to IR patients. CRT was given to the large HR patient group (50%). The aims of this study were (a) to assess the feasibility and the therapeutic impact of intensive chemotherapy for ALL in our multicenter setting; (b) to evaluate whether CRT could be safely replaced by extended IT-MTX in IR patients accounting for 30% of all cases. 5 Study 91. The AIEOP-ALL 91 Study was conducted from March 1991 to April 1995 and involved all AIEOP centers. In the SR arm, induction phase IB was omitted and HD-MTX was reduced from 5 to 2 g/m 2 ; at the beginning of maintenance therapy, patients were randomized to receive or not protracted HD-L-ASP. Patients at IR received the same therapy of previuos Study 88, with the notable exception that they were randomized at the beginning of reinduction therapy to receive or not HD-L- ASP. Protracted IT therapy was given to both SR and IR patients. The group of HR patients was relatively small (17%) and after the first 5 weeks of induction therapy (VCR/PDN/DNR/L-ASP) treatment was continued by adopting a novel therapeutic approach (based on the experience of the BFM studies for ALL relapses) consisting of nine intensive polychemotherapy blocks, 17 followed by CRT. Maintenance therapy included 6-mercaptopurine and MTX. 6 Study 95. In Study 95, the SR group was highly selected on the basis of age, WBC count, immunophenotype and DNA index, accounting for only 7% of the total population. Treatment consisted of three-drug induction (VCR/PDN/L-ASP), HD-MTX (2 g/m 2 4), reinduction phase with Protocol II and maintenance. IR patients received the whole Protocol I as induction therapy; HD-MTX dose was reduced to 2 g/m 2 ; protocol II was given as reinduction therapy; at the beginning of maintenance, patients were randomized to receive or not to receive VCR/ DXM pulses. The HR group received the entire Protocol I, three polychemotherapy blocks, a double-delayed intensification (Protocol II as reinduction given twice) with CRT given between the two reinduction phases; maintenance consisted of 6-mercaptopurine, MTX and VCR/PDN pulses. 11 Statistical analysis Event-free survival (EFS±s.e.) and survival time are defined from the date of diagnosis until the date of failure. In EFS, failure is defined as one of the following events: no complete remission (considered as a failure at time zero), death in induction, relapse, death in complete remission and development of a second malignancy. In survival, the only event considered is death for any cause. For subjects with no failure, EFS and survival times are censored at the last follow-up date. EFS and survival probabilities are estimated according to Kaplan Meier with s.e. according to Greenwood, and the log-rank test is used for their comparison. Cumulative incidence functions of isolated central nervous system (CNS) or testicular relapse, of CNS or testicular relapse in conjunction with another type of relapse and of second malignant neoplasms are estimated accounting for all other types of failure in term of competing events. 18 Follow-up was updated as of December 2008 by queries to the AIEOP centers that reported the information in the last visit or by phone contact. The follow-up information for patients in CCR was beyond 15 years in 72, 54 and 62% for studies 82, 87 and 88 and beyond 10 years in 78% of patients in study 91. No linkage with population tumor registries was possible. Results The 10-year EFS progressively improved from 53% in Study 82 to 72% in Study 95, whereas survival increased from 64 to 82% (Table 1). Between 10 and 15 years from diagnosis EFS decreased overall of 0.7% and survival of 1.2%.

3 Table 1 Treatment outcome according to AIEOP studies 257 Total therapy studies Year N patients N induction failures(%) 45 (5.0) 12 (1.9) 19 (4.8) 38 (3.2) 27 (1.6) Induction deaths Resistant a N relapses (%) 346 (38.4) 207 (32.7) 115 (29.0) 312 (26.2) 398 (22.8) Hematological only CNS only Testicular only Hematological+CNS Hematological+testicular Hematological+other Other relapses sites Not known N second malignant neoplasm (%) 8 (0.9) 2 (0.3) 2 (0.5) 6 (0.5) 5 (0.3) N death in remission (%) 30 (3.3) 10 (1.6) 7 (1.8) 23 (1.9) 27 (1.6) 10-year cumulative risk of death in remission (s.e.) 3.2% (0.6) 1.6% (0.5) 1.3% (0.6) 1.9% () 1.6% (0.3) 10-year event-free survival (s.e.) 52.8% (1.7) 63.0% (2.0) 64.8% (2.4) 68.4% (2.4) 71.7% (1.3) 10-year overall survival (s.e.) 63.8% (1.6) 74.9% (1.8) 74.3% (2.2) 76.9% (1.2) 82.4%(1.0) Abbreviations: AIEOP, Italian Association of Pediatric Hematology and Oncology; CNS, central nervous system; BFM, Berlin-Frankfurt-Muenster. a Resistance was defined as failure to obtain a complete remission: at the end of 4 week induction in protocols 82 and 87; by the end of BFM protocol I (within 12 weeks from diagnosis) in Study 88; by the end of first high-risk (HR) block following phase IA of BFM protocol I (within 8 weeks) in Study 91; by the end of three HR blocks following BFM protocol I (within 21 weeks) in Study 95. Protocol-specific treatment outcome Study 82. The 15-year EFS and survival in the 902 eligible and evaluable patients were 52.5% (±1.7) and 62.2% (±1.7), respectively (Table 2). The median follow-up was 21.3 years (range years for the 564 patients still alive). The 15-year cumulative risk estimates for isolated CNS and any CNS relapses were 10.1% (±1.0) and 14.0% (±1.2), respectively. Of the 483 male patients, 44 developed testicular relapse (20 isolated, 23 combined with hematological relapse and 1 combined with CNS relapse), with a cumulative incidence of 9.3% (±1.3) at 10 years. (Figure 1). Secondary malignant neoplasms included Hodgkin lymphoma (n ¼ 1), non-hodgkin lymphoma (n ¼ 1), astrocytoma (n ¼ 2), thyroid carcinoma (n ¼ 2), neuroblastoma (n ¼ 1) and breast cancer (n ¼ 1). Other neoplasms reported were meningioma (n ¼ 2) and parotideal adenoma (n ¼ 1). The cumulative risk of any secondary neoplasms was 0.6% (±0.3) at 10 years and 0.6% (±0.3) at 15 years. With this risk-based therapy, the 15- year survival obtained was of 62.2% overall and of 70.3% (±1.8) in non-hr patients. About 75% of patients were not exposed to alkylating agents or epipodophyllotoxins, and received no (SR patients, 12% of the total) or very low (90 mg/ m 2 for IR patients, 63% of the total population) cumulative dosage of anthracyclines. Study 87. The 15-year EFS and survival in the 632 eligible and evaluable patients were 62.5% (±2.0) and 74.2% (±1.8), respectively (Table 3). The median follow-up was 16.6 years (range years for the 474 patients still alive). The cumulative risk estimates for isolated CNS and any CNS relapses were 8.3% (±1.1) and 10.8% (±1.3) at 15 years, respectively. Of the 358 male patients, 37 developed testicular relapse (19 isolated, 17 combined with hematological relapse, and 1 combined with hematological and CNS relapse), with a cumulative incidence of 1% (±1.6) at 10 years (Figure 2). Two secondary malignant neoplasms were diagnosed (one case of acute myeloid leukemia (AML) and one case of brain tumor). Moreover, a meningioma was reported. The cumulative risk of any secondary neoplasms was % (±) at 10 years and 0.5% (±0.3) at 15 years (Figure 2). A significant improvement of long-term EFS and survival rates with respect to the previous Study 82 was associated with treatment intensification using anthracyclines both in induction and reinduction phases. The HR group, which comprised 30% of the population, achieved a 15-year EFS and survival, respectively, of 6% (±3.7) and 66.6% (±3.5). These relatively favorable results were achieved with a protracted use of HD-L-ASP. Study 88. The 15-year EFS and survival in the 396 eligible and evaluable patients were 63.8% (±2.5) and 73.6% (±2.3), respectively (Table 4). The median follow-up was 17.1 years (range years for the 289 patients still alive). Substitution of extended IT-MTX for CRT in the IR group treated with intensive, BFM-type chemotherapy, allowed to obtain a 15- year cumulative incidence of isolated CNS relapse of 0.8% (±0.8). Notably, SR patients treated with less intensive reinduction therapy (protocol III instead of protocol II), HD- MTX (5 g/m 2 ), but not receiving extended IT-MTX during maintenance chemotherapy, had a 15-year cumulative incidence of isolated CNS relapse of 6.3% (±2.7). 5 Secondary neoplasms included thyroid carcinoma (n ¼ 1) and uterus carcinoma (n ¼ 1). One meningioma was also reported. The cumulative incidence of any secondary neoplasms was 0.3% (±0.3) at 10 years and 0.3% (±0.3) at 15 years (Figure 3). This study, in which induction death occurred in 1.3% and death in complete remission in 1.8% of patients, showed the feasibility of BFM therapy in Italian centers and paved the way to the introduction of BFM treatment in subsequent AIEOP studies.

4 258 Table 2 Treatment results according to presenting features in 902 patients treated in AIEOP-ALL 82 Factors No. of patients Event-free survival±s.e. (%) Overall survival±s.e. (%) Year 5 Year 10 Year 15 P-value Year 5 Year 10 Year 15 P-value Overall (1.7) 52.8 (1.7) 52.5 (1.7) 7 (1.5) 63.8 (1.6) 62.2 (1.7) Cell lineage B (1.8) 55.5 (1.8) 55.2 (1.8) o (1.6) 66.7 (1.7) 64.9 (1.7) o01 T (4.6) 33.1 (4.5) 33.1 (4.5) 46.6 (4.8) 42.8 (4.8) 42.8 (4.8) B-lineage NCI Standard (2.0) 62.0 (2.1) 61.8 (2.1) o (1.7) 74.3 (1.9) 72.2 (1.9) o01 NCI High (3.3) 39.1 (3.3) 38.6 (3.3) 56.8 (3.3) 47.6 (3.4) 46.5 (3.4) T-lineage NCI Standard (8.5) 56.0 (8.5) 56.0 (8.5) o (7.8) 70.7 (7.8) 70.7 (7.8) o01 NCI High (5.3) 22.7 (4.8) 22.7 (4.8) 35.6 (5.6) 30.1 (5.3) 30.1 (5.3) Sex Male (2.3) 45.8 (2.3) 45.8 (2.3) o (2.1) 59.8 (2.3) 58.3 (2.3) o1 Female (2.4) 60.8 (2.4) 6 (2.4) 72.8 (2.2) 68.3 (2.3) 66.6 (2.3) Age at diagnosis (years) o (11.6) 31.3 (11.6) 31.3 (11.6) 37.5 (12.1) 31.3 (11.6) 31.3 (11.6) (1.8) 54.9 (1.9) 54.8 (1.9) o (1.7) 66.6 (1.8) 64.8 (1.8) o01 X (4.1) 44.3 (4.1) 43.5 (4.1) 61.1 (4.0) 53.5 (4.1) 52.6 (4.2) WBC 10 9 /l o (2.5) 59.1 (2.5) 58.5 (2.5) 78.9 (2.1) 72.2 (2.3) 69.7 (2.4) (2.7) 59.6 (2.7) 59.6 (2.7) o (2.4) 70.5 (2.5) 69.5 (2.6) o (5.0) 27.6 (4.9) 27.6 (4.9) 49.0 (5.5) 37.5 (5.4) 36.2 (5.4) X (4.7) 24.1 (4.5) 24.1 (4.5) 34.1 (5.0) 27.4 (4.7) 27.4 (4.7) CNS status Positive 7 Negative (1.7) 52.9 (1.7) 52.7 (1.7) 70.5 (1.5) 63.9 (1.6) 62.2 (1.7) Not known 5 Abbreviations: AIEOP, Italian Association of Pediatric Hematology and Oncology; ALL, acute lymphoblastic leukemia; CNS, central nervous system; NCI, National Cancer Institute. Probability %(1.5) 56.4%(1.7) 13.8%(1.2) 63.8%(1.6) 62.2%(1.7) 52.8%(1.7) 14.0%(1.2) 52.5%(1.7) 14.0%(1.2) Survival EFS Study 91. The 15-year EFS and survival in the 1192 eligible and evaluable patients were 67.7% (±1.4) and 76.2% (±1.3), respectively (Table 5). The median follow-up was 13.9 years (range years for the 916 patients still alive). The cumulative risk estimates for isolated CNS and any CNS relapses were 1.6% (±) and 2.7% (±0.5) at 15 years, respectively. Of the 669 male patients, 34 developed testicular relapse (14 isolated, 19 combined with hematological relapse and 1 combined with CNS relapse) with a cumulative incidence of 5.1% (±0.9) at 10 years 6 (Figure 4). CNS 10.1%(1.0) 10.1%(1.0) 10.1%(1.0) Isolated CNS Years from diagnosis Figure 1 Event-free survival (EFS), survival and cumulative incidence of isolated or any central nervous system (CNS) relapse in 902 patients of Study Cumulative Incidence SR patients were randomized to receive a reduced intensity treatment (omission of phase IB and reduction of the dose of HD-MTX from 5 to 2 g/m 2 ) with or without HD-L-ASP. Patients in the arm without HD-L-ASP had an outcome inferior to results expected when treated with conventional BFM treatment; significantly better EFS was obtained in the HD-L-ASP arm, showing that this additional therapy allowed to compensate for the disadvantage because of decreased treatment intensity. 8,19 IR patients were randomized to receive or not to receive protracted HD-L-ASP (mainly Erwinia product) on top of conventional BFM therapy; 9 no significant difference in the long-term disease-free survival was observed in the two treatment arms (P-value ¼ 0.69), with estimated values at 15 years from randomization of 71.5% (±2.7) and 72.8% (±2.8) in the no-hd-l-asp and HD-L-ASP arms, respectively. Subanalyses showed that PGR IR patients with T-ALL and WBC count X /mm 3 (accounting for about 1% of the total population) who had not received CRT had a dismal outcome (10-year EFS 7.1% (±6.9)). 12 Replacing induction phase IB, HD-MTX and reinduction phase protocol II, with intensive block therapy did not improve treatment results in HR patients who had a 15- year EFS of 37.9% (±3.5). Secondary malignant neoplasms included non-hodgkin lymphoma (n ¼ 1), medulloblastoma (n ¼ 1), neuronal tumor (n ¼ 1, not better specified), Ewing sarcoma (n ¼ 1), rhabdomyosarcoma (n ¼ 1) and thyroid carcinoma (n ¼ 1). The cumulative risk of any secondary neoplasms was 0.3% (±0.1) at 10 years and % (±) at 15 years.

5 Table 3 Treatment results according to presenting features in 632 patients treated in AIEOP-ALL Factors No. of patients Event-free survival±s.e. (%) Overall survival±s.e. (%) Year 5 Year 10 Year 15 P-value Year 5 Year 10 Year 15 P-value Overall (1.9) 63.0 (2.0) 62.5 (2.0) 78.6 (1.7) 74.9 (1.8) 74.2 (1.8) Cell lineage B (2.0) 64.5 (2.1) 64.0 (2.1) o (1.7) 77.4 (1.8) 76.7 (1.8) o01 T (5.9) 51.0 (5.9) 51.0 (5.9) 56.5 (5.9) 55.0 (5.9) 55.0 (5.9) B-lineage NCI Standard (2.2) 67.5 (2.3) 67.5 (2.3) (1.8) 80.9 (2.0) 80.3 (2.0) o01 NCI High (4.1) 56.3 (4.2) 55.2 (4.2) 71.5 (3.8) 67.8 (3.9) 66.7 (4.0) T-lineage a NCI Standard (8.4) 74.1 (8.4) 74.1(8.4) (8.0) 77.8 (8.0) 77.8 (8.0) 02 NCI High (7.4) 35.4 (7.3) 35.4 (7.3) 42.1 (7.5) 39.7 (7.5) 39.7 (7.5) Sex Male (2.6) 54.7 (2.7) 54.3 (2.7) o (2.4) 68.5 (2.5) 67.6 (2.5) o01 Female (2.5) 74.0 (2.7) 73.3 (2.8) 86.1 (2.1) 83.3 (2.3) 82.8 (2.3) Age at diagnosis (years) o (2.0) 66.3 (2.1) 65.7 (2.1) o (1.7) 77.7 (1.8) 77.2 (1.9) o01 X (5.1) 45.0 (5.1) 45.0 (5.1) 63.8 (4.9) 59.4 (5.0) 57.7 (5.2) WBC 109/l a o (2.8) 66.3 (2.9) 65.8 (2.9) 86.2 (2.1) 82.4 (2.3) 81.5 (2.4) (3.1) 62.2 (3.2) 62.2 (3.2) o (2.8) 72.4 (3.0) 71.6 (3.1) o (5.7) 69.3 (5.9) 69.3 (5.9) 77.4 (5.3) 74.0 (5.6) 74.0 (5.6) X (6.8) 40.7 (6.8) 37.5 (7.0) 45.5 (7.0) 45.5 (7.0) 45.5 (7.0) CNS status Positive 4 Negative (1.9) 63.1 (2.0) 62.6 (2.0) 78.9 (1.7) 74.9 (1.8) 74.2 (1.8) Not known 19 Abbreviations: AIEOP, Italian Association of Pediatric Hematology and Oncology; ALL, acute lymphoblastic leukemia; CNS, central nervous system; NCI, National Cancer Institute. a One patient with data not known. Probability %(1.7) 66.8%(1.9) 74.9%(1.8) 63.0%(2.0) Survival Study 95. The 10-year EFS and survival in the 1743 eligible and evaluable patients were 71.7% (±1.3) and 82.4% (±1.0), respectively (Table 6). The median follow-up was 7.7 years (range 13.1 years for the 1459 patients still alive). The cumulative risk estimates for isolated CNS and any CNS relapses were 1.2% (±0.3) and 2.3% (±) at 10 years, respectively. Of the 942 male patients, 42 developed EFS 9.7%(1.2) 10.8%(1.3) 10.8%(1.3) CNS %(1.1) 8.3%(1.1) 8.3%(1.1) Isolated CNS Years from diagnosis 74.2%(1.8) 62.5%(2.0) Figure 2 Event-free survival (EFS), survival and cumulative incidence of isolated or any central nervous system (CNS) relapse in 632 patients of Study Cumulative Incidence testicular relapse (25 isolated, 16 combined with hematological relapse and 1 combined with CNS and eye relapse) this leading to a cumulative incidence of 5.7% (±1.0) at 10 years. (Figure 5). DNA index was used to stratify patients in this study. The EFS at 10 years of patients with DNA index X1.16 and o 1.6 was 83.9% (±2.1), as opposed to an EFS of 69.4% (±1.4) at 10 years in the remaining patients. The SR group included only 6.6% of patients, with favorable WBC count, age and DNA index and received a reduced intensity induction treatment, which consisted of PDN, VCR and L-ASP, mainly Erwinia product. EFS in this highly selected subgroup was not satisfactory (85.0% (±3.4) at 10 years), although most relapses could be rescued by salvage therapy resulting into a survival probability of 94.5% (±2.2) at 10 years. 10 IR patients (79.4% of total population) were randomized to receive or not to receive VCR/DXM pulses during maintenance; the disease-free survival did not significantly differ (P-value 0.53), and 10-year figures in the two arms were 76.3% (±2.3) and 76.5% (±1.9), respectively. Patients with PGR, T-ALL and WBC count X1000/cmm received the same treatment as in Study 91 but for the addition of preventive CRT (18 Gy); their 10-year EFS was 65.9% (±7.2), significantly better (P-valueo01) than the EFS obtained in Study 91 (7.1% (±6.9)). HR patients (14.0%) were treated with conventional BFM therapy intensified with three polychemotherapy blocks and double-delayed

6 260 Table 4 Treatment results according to presenting features in 396 patients treated in AIEOP-ALL 88 Factors No. of patients Event-free survival±s.e. (%) Overall survival±s.e. (%) Year 5 Year 10 Year 15 P-value Year 5 Year 10 Year 15 P-value Overall (2.4) 64.8 (2.4) 63.8 (2.5) 78.2 (2.1) 74.3 (2.2) 73.6 (2.3) Cell lineage B (2.5) 65.8 (2.6) 64.5 (2.6) o (2.2) 75.2 (2.4) 74.4 (2.4) o01 T (6.6) 58.8 (6.8) 58.8 (6.8) 7 (6.2) 68.5 (6.3) 68.5 (6.3) B-lineage NCI Standard (2.9) 73.0 (2.9) 71.1 (3.1) o (2.4) 81.5 (2.6) 80.8 (2.7) o01 NCI High (4.7) 50.7 (4.8) 50.7 (4.8) 68.2 (4.4) 62.3 (4.7) 61.1 (4.7) T-lineage NCI Standard (10.8) 83.3 (10.8) 83.3 (10.8) (8.0) 91.7 (8.0) 91.7 (8.0) 5 NCI High (7.6) 51.7 (7.8) 51.7 (7.8) 64.3 (7.4) 61.9 (7.5) 61.9 (7.5) Sex Male (3.2) 62.0 (3.3) 60.7 (3.4) (2.9) 70.1 (3.1) 68.8 (3.2) 2 Female (3.5) 68.4 (3.5) 67.7 (3.6) 82.8 (2.9) 79.7 (3.1) 79.7 (3.1) Age at diagnosis (years) o (11.6) 31.3 (11.6) 31.3 (11.6) 56.3 (12.4) 49.2 (12.7) 49.2 (12.7) (2.6) 68.1 (2.7) 66.8 (2.7) o (2.2) 77.8 (2.4) 76.9 (2.5) 03 X (5.8) 58.2 (5.8) 58.2 (5.8) 68.1 (5.5) 65.0 (5.7) 65.0 (5.7) WBC±109/l o (3.3) 74.7 (3.4) 73.8 (3.5) 85.8 (2.7) 81.2 (3.1) 81.1 (3.1) (4.1) 65.4 (4.1) 63.3 (4.2) o (3.6) 75.5 (3.7) 74.4 (3.8) o (8.1) 39.5 (7.9) 39.5 (7.9) 63.2 (7.8) 57.3 (8.1) 54.1 (8.3) X (6.5) 53.0 (6.6) 53.0 (6.6) 67.2 (6.2) 63.8 (6.3) 63.8 (6.3) CNS status Positive (8.7) 61.0 (9.7) 61.0 (9.7) (7.1) 8 (8.0) 8 (8.0) 0.65 Negative (2.5) 65.1 (2.5) 64.0 (2.5) 77.7 (2.2) 73.9 (2.3) 73.2 (2.4) t(9;22) Present 7 Other 389 t(4;11) Present 5 Other 391 Abbreviations: AIEOP, Italian Association of Pediatric Hematology and Oncology; ALL, acute lymphoblastic leukemia; CNS, central nervous system; NCI, National Cancer Institute. Probability %(2.1) 67.8%(2.4) 74.3%(2.2) 64.8%(2.4) 73.6%(2.3) 63.8%(2.5) Survival intensification (Protocol II given twice); this choice led to a more favorable outcome (EFS at 10 years of 5% (±3.3)) when compared with Study 91. EFS 8.6%(1.4) 8.9%(1.4) 8.9%(1.4) CNS %(1.1) 5.1%(1.1) 5.1%(1.1) Isolated CNS Years from diagnosis Figure 3 Event-free survival (EFS), survival and cumulative incidence of isolated or any central nervous system (CNS) relapse in 396 patients of Study Cumulative Incidence Secondary malignant neoplasms included ALL (n ¼ 1, different clone and immunophenotype with respect to first diagnosis), AML (n ¼ 1), non-hodgkin lymphoma (n ¼ 1), synovial sarcoma (n ¼ 1) and salivary gland tumor (n ¼ 1). The cumulative risk of any secondary neoplasms was % (±) at 10 years. 11 Treatment results according to presenting features Female patients showed over the years a steady improvement in treatment results with treatment intensification; improvement was less evident in males. The outcome in infants (o1 year of age at diagnosis), which was quite poor (B30% EFS at 10 and 15 years) in the first studies, improved in Study 95 (51% EFS at 10 years). Prognosis for patients with WBC count X / mm 3 was very poor in Study 82 (24% EFS at 10 years), but improved markedly (to 56%) with treatment intensification in subsequent studies, with the only exception of Study 91, which had poor results in the HR arm. Patients with B-lineage ALL had a progressive increase in long-term treatment results up to a 72% EFS at 10 and 15 years in studies 95 and 91 as compared to

7 Table 5 Treatment results according to presenting features in 1192 patients treated in AIEOP-ALL Factors No. of patients Event-free survival±s.e. (%) Overall survival ± s.e. (%) Year 5 Year 10 Year 15 P-value Year 5 Year 10 Year 15 P-value Overall (1.3) 68.4 (1.4) 67.8 (1.4) 79.1 (1.2) 76.9 (1.2) 76.2 (1.3) Cell lineage B (1.3) 72.5 (1.4) 71.7 (1.4) o (1.2) 81.2 (1.2) 8 (1.3) o01 T (4.1) 38.7 (4.1) 38.7 (4.1) 47.2 (4.2) 45.6 (4.2) 45.6 (4.2) B-lineage NCI Standard (1.5) 77.1 (1.5) 76.9 (1.5) o (1.2) 85.6 (1.3) 85.1 (1.3) o01 NCI High (2.9) 6 (2.9) 57.6 (3.2) 70.8 (2.7) 69.3 (2.8) 67.6 (3.0) T-lineage NCI Standard (7.0) 62.0 (7.3) 62.0 (7.3) o (7.1) 64.0 (7.2) 64.0 (7.2) o01 NCI High (4.6) 27.8 (4.6) 27.8 (4.6) 38.1 (4.9) 37.0 (4.9) 37.0 (4.9) Sex Male (1.8) 64.3 (1.9) 63.7 (1.9) o (1.7) 73.8 (1.7) 72.9 (1.8) 05 Female (1.9) 73.6 (1.9) 73.0 (2.0) 82.5 (1.7) 81.0 (1.7) 8 (1.8) Age at diagnosis (years) o (10.3) 33.3 (10.3) 33.3 (10.3) 52.4 (10.9) 52.4 (10.9) 52.4 (10.9) (1.4) 72.5 (1.4) 72.2 (1.5) o (1.2) 80.8 (1.3) 8 (1.3) o01 X (3.6) 51.1 (3.7) 48.7 (3.9) 60.7 (3.6) 59.6 (3.6) 57.2 (3.9) WBC 10 9 /l o (1.8) 75.4 (1.8) 75.4 (1.8) 87.2 (1.4) 85.3 (1.5) 84.8 (1.5) (2.2) 70.7 (2.3) 69.3 (2.4) o01 8 (2.0) 77.4 (2.1) 76.4 (2.2) o (5.3) 63.4 (5.3) 61.2 (5.6) 75.6 (4.7) 73.1 (4.9) 71.3 (5.1) X (4.0) 37.9 (4.0) 37.9 (4.0) 46.2 (4.1) 45.5 (4.1) 45.5 (4.1) CNS status Positive (8.8) 38.7 (8.8) 38.7 (8.8) 41.9 (8.9) 41.9 (8.9) 41.9 (8.9) Negative (1.3) 69.6 (1.4) 68.9 (1.4) o01 8 (1.2) 78.2 (1.2) 77.5 (1.3) o01 Not known 7 t(9;22) Present (10.7) 35.0 (10.7) 35.0 (10.7) 49.5 (11.3) 49.5 (11.3) 49.5 (11.3) Other 1172 t (4;11) Present 9 Other 1183 Abbreviations: AIEOP, Italian Association of Pediatric Hematology and Oncology; ALL, acute lymphoblastic leukemia; CNS, central nervous system; NCI, National Cancer Institute. Probability %(1.2) 70.9%(1.3) 2.6%(0.5) 76.9%(1.2) 68.4%(1.4) 2.7%(0.5) 55% EFS in the oldest studies. Results obtained in patients with T-lineage ALL improved in Studies 87, 88 and 95, suggesting that the use of protracted HD-L-ASP (HR arm of Study 87) or of EFS CNS Years from diagnosis %(1.3) Survival 67.8%(1.4) %(0.5) Figure 4 Event-free survival (EFS), survival and cumulative incidence of isolated or any central nervous system (CNS) relapse in 1192 patients of Study 91. Cumulative Incidence the BFM treatment elements Phase IB þ HD-MTX þ reinduction (Studies 88 and 95) is of benefit for this ALL subtype. Results obtained in T-ALL were less favorable in Study 91, particularly in patients with high WBC count treated in the IR arm without CRT, 16 but also in patients with PPR treated with chemotherapy blocks in the HR arm (EFS 32.0% (±9.3)). Moreover, the B-cell precursor ALL, PPR patients treated with polychemotherapy blocks in Study 91 had a poor outcome (10-year EFS of 46.2% (±6.2)). PPR patients had instead a better outcome in Study 95, in which they were treated with conventional BFM therapy intensified with three polychemotherapy blocks and doubledelayed intensification (10-year EFS of 51.5% (±6.6) for T-ALL (P ¼ 0.11) and 53.8% (±4.6) for B-cell precursor ALL (P ¼ 0.31) for comparison with Study 91). TEL/AML1-positive patients had an EFS of 85.1% (±2.5) and 79.9% (±3.0) and a survival of 94.5% (±1.6) and 93.5% (±1.7) at 5 and 10 years, respectively, in Study 95. These data show that this patients subset is at higher risk of developing late relapses, although maintaining high probability of rescue with second line chemotherapy.

8 262 Table 6 Treatment results according to presenting features in 1743 patients treated in AIEOP-ALL 95 Factors No. of patients Event-free survival±s.e. (%) Overall survival±s.e. (%) Year 5 Year 10 Year 15 P-value Year 5 Year 10 Year 15 P-value Overall (1.0) 71.7 (1.3) F 85.5 (0.8) 82.4 (1.0) F Cell lineage B (1.1) 72.7 (1.3) o (0.8) 84.2 (1.1) o01 T (3.5) 64.1 (3.6) 70.3 (3.3) 68.4 (3.5) B-lineage NCI Standard (1.2) 75.9 (1.5) o (0.9) 87.7 (1.2) o01 NCI High (2.2) 64.7 (2.5) 79.2 (1.9) 75.2 (2.2) T-lineage NCI Standard (6.4) 77.0 (6.4) (6.0) 81.3 (6.0) 4 NCI High (4.0) 6 (4.2) 66.9 (3.9) 64.4 (4.1) Sex Male (1.5) 67.6 (1.8) o (1.2) 79.6 (1.5) 02 Female (1.4) 76.5 (1.7) 87.9 (1.2) 85.7 (1.4) Age at diagnosis (years) o (9.0) 51.6 (9.0) 57.6 (9.0) 57.6 (9.0) (1.1) 74.0 (1.4) o (0.9) 85.3 (1.1) o (2.8) 62.7 (3.2) 77.1 (2.6) 71.9 (3.0) (7.3) 68.5 (7.3) 76.7 (7.1) 72.7 (7.1) WBC 10 9 /l o (1.4) 76.1 (1.7) 89.6 (1.1) 87.2 (1.3) (1.8) 72.7 (2.3) o (1.4) 83.5 (1.9) o (3.7) 62.4 (4.1) 77.8 (3.3) 73.0 (3.8) X (3.7) 56.2 (4.0) 66.9 (3.6) 65.5 (3.6) CNS status Positive (8.0) 77.8 (8.0) (7.5) 81.5 (7.5) 0.62 Negative (1.0) 71.6 (1.3) 85.7 (0.9) 82.5 (1.0) Not known 5 t (9;22) Present (7.4) 2 (7.3) o (8.1) 28.7 (7.8) o01 Absent (1.1) 73.1 (1.3) 86.9 (0.9) 84.0 (1.1) Not performed 143 t (4;11) Present (11.5) 61.1 (11.5) (11.5) 61.1 (11.5) o01 Absent 1579 Not performed (1.1) 72.0 (1.3) 86.3 (0.9) 83.1 (1.1) t (12;21) Present (2.5) 79.9 (3.0) (1.6) 93.5 (1.7) o01 Absent (1.7) 71.3 (1.8) 85.0 (1.4) 82.5 (1.5) Not performed 842 DNA index Favourable (2.1) 83.9 (2.1) o (1.4) 91.9 (1.7) o01 Not favourable (1.2) 69.4 (1.4) 84.2 (1.0) 81.0 (1.2) Not performed 74 Abbreviations: AIEOP, Italian Association of Pediatric Hematology and Oncology; ALL, acute lymphoblastic leukemia; CNS, central nervous system; NCI, National Cancer Institute. Discussion Overall results at 5, 10 and 15 years show that EFS of patients with ALL has an absolute decrease of 3.2% and of 0.6% in the second and third 5-year period after diagnosis, respectively. Out of 152 events occurring after 5 years, 129 were relapses (hematological 118 and extramedullary 11), which in large part are likely to be rescued by salvage therapies. Only 17 were secondary malignant neoplasms, which gives a long-term incidence figure lower than that reported by other groups. The lack in Italy of a national cancer population registry does not allow to control whether there is underreporting in the

9 Probability %(0.8) 75.9%(1.0) 2.2%() 1.2%(0.3) 6 Survival 82.4%(1.0) 71.7%(1.3) 2.3%() 1.2%(0.3) follow-up provided by pediatric centers who were initially treating the child. Optimal CNS-directed treatment in childhood ALL remains questionable. Although the primary aim of this treatment is to reduce the incidence of leukemia relapse in the CNS, yet the treatment design must consider that the use of CRT is associated with undesired severe late effects. 20,21 The AIEOP ALL Study group progressively decreased, over the past 20 years, the proportion of patients undergoing CRT, whereas increasing the intensity of both systemic and CNS-directed chemotherapy. IT therapy consisted of IT-MTX or triple intrathecal therapy. Results obtained for IR patients not irradiated who were treated with triple intrathecal therapy in Study 91 were superimposable to those obtained with IT-MTX in Study The frequency of irradiated patients decreased from 88% in Study 82 and 87 to 49% in Study 88, and to 15% in Study 91 and 95. This therapeutic strategy (increased intensity of systemic and IT therapy and reduced use of CRT) provided a better disease control with a marked decrease of systemic relapses as well as long-term isolated CNS relapses, which dropped from 8% in Study 87 (Figure 2) to o2% in Study 95 (Figure 5). All curves of cumulative incidence of CNS relapse reached a plateau at 10 years. Historical comparison suggests that 5 g/m 2 (Study 91) or 2 g/m 2 (Study 95) of HD-MTX in non-hr, B-lineage, non-cns-positive ALL is equally effective to prevent CNS relapses (cumulative incidence of 2.2% (±0.6) vs 2.0% (±), respectively) and that CRT (Study 91 vs 95) may be of benefit for PGR T-ALL with hyperleukocytosis. The decreased dose of HD-MTX did not influence the rate of testicular relapses, as well. Indeed, subanalysis shows that cumulative incidence of testicular relapses at 10 years in males with non-hr, B-lineage, non-cns-positive ALL treated with HD-MTX 5 or 2 g/m 2 was of 5.8% (±1.3) and 5.9% (±1.3) in Studies 91 and 95, respectively. Overall results show that in Study 82, in which limited treatment intensity had been applied, very poor results were obtained in patients classified as HR by National Cancer Institute (NCI) criteria, in T-ALL and in males; in Studies 87 and 88, treatment intensification allowed a clear improvement in the prognosis of these subgroups. Results of Studies 91 and 95 suggest that block therapy (Study 91) may be inferior to an intensified conventional BFM treatment for patients with hyperleukocytosis or other HR features. 22,23 Future plans In the cooperative AIEOP-BFM-ALL 2000 Study, the stratification of patients has been based on the detection of minimal EFS CNS Isolated CNS Years from diagnosis 12 Figure 5 Event-free survival (EFS), survival and cumulative incidence of isolated or any central nervous system (CNS) relapse in 1743 patients of Study Cumulative Incidence residual disease by PCR at two time points (weeks 5 and 12). 24 Common randomized studies were conducted with the BFM group to evaluate the impact of DXM in induction therapy in all patients and of different reinduction treatments in SR, IR and HR arms. This last study has been closed to recruitment at July A new study is planned to start by the end of This new study will be common (identical) for the AIEOP and BFM groups. The stratification of patients on the basis of minimal residual disease will take into account not only the PCR information at weeks 5 and 12, but also the response evaluated at day 15 by flowcytometry. 25,26 Clinical studies will be conducted in a randomized manner to evaluate the efficacy of treatment de-intensification in patients TEL/AML1 positive or with B-lineage ALL and very favorable early response, and the impact of treatment intensification with pegylated-l-asp in IR or HR patients. Conflict of interest The authors declare no conflict of interest. Acknowledgements We are grateful to all parents associations and charities, which continuously supported the clinical and research work. This study has been partly supported by grants from the Ministero Università Ricerca Scientifica e Tecnologica (MURST), Grant , AIRC (MGV) and PRIN (GB). References 1 Paolucci G, Masera G, Vecchi V, Marsoni S, Pession A, Zurlo MG, et al. ALL Steering committee of the AIEOP. 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Pediatria (Dr P Pierani) Bari, Clinica Pediatrica (Prof. D De Mattia, Dr N Santoro) Bergamo, Div. Pediatria (Dr M Provenzi) Bologna, Clinica Pediatrica (Prof. A Pession, Dr R Rondelli) Brescia, Clinica Pediatrica (Dr F Porta) Cagliari, Servizio Oncoematologia Pediatrica (Prof. PF Biddau, Dr R Mura) Catania, Div. Oncoematologia Pediatrica (Prof G Schilirò, Dr L Lo Nigro) Catanzaro, Div. Ematologia (Dr C Consarino) Cosenza, U.O. Pediatria (Dr D Sperlì) Firenze, Ospedale Meyer, Dip. Pediatria, U.O. Oncoematologia Pediatrica (Dr M Aricò, Dr A Lippi) Genova, Ist G.Gaslini (Dr G Dini, Dr C Micalizzi) Milano, Clinica Pediatrica De Marchi (Dr D Portaleone) Milano, Divisione di Pediatria, Ospedale Niguarda, (Dr F Fedeli) Modena, Clinica Pediatrica (Prof. P Paolucci) Monza, Clinica Pediatrica (Prof. G Masera, Dr V Conter, Prof. A Biondi, Dr M Jankovic, Dr C Rizzari) Napoli, Divisione di Oncoematologia Pediatrica, Ospedale Pausillipon (Dr V Poggi, Dr R Parasole) Napoli, II Università, Dip. Pediatria, Servizio Autonomo Oncologia Pediatrica (Prof. MT Di Tullio, Prof. F Casale) Padova, Clinica Pediatrica II (Prof. M Carli, Prof. C Messina) Palermo, Clinica Pediatrica I ( Dr P D Angelo) Parma, Clinica Pediatrica (Dr G Izzi, Dr P Bertolini) Pavia, Clinica Pediatrica (Prof. F Locatelli, Dr G Giorgiani, Dr M Zecca) Perugia, Div. Oncoematologia Pediatrica, Ospedale Silvestrini (Prof. F Aversa) Pesaro, Divisione di Pediatria (Dr L Felici) Pesaro, Ematologia, Ospedale di Muraglia (Dr G Visani) Pescara, Divisione di Pediatria (Dr P Di Bartolomeo) Pisa, Clinica Pediatrica III (Dr C Favre) Reggio Calabria, Div. Ematologia, Ospedali Riuniti (Prof. F Nobile, Dr M Comis) Roma, Div. Ematologia Pediatrica, Osp. Bambin Gesù (Dr G De Rossi, Dr M Luciani) Roma, Cattedra Ematologia (Prof. R Foà, Dr AM Testi) Roma, Clinica Pediatrica (Prof. M Castello) Roma, Oncologia Pediatrica, Policlinico Gemelli (Prof. R Riccardi) San Giovanni Rotondo, Div. Pediatria, Ospedale Casa Sollievo della Sofferenza (Dr S Ladogana) Siena, Clinica Pediatrica (Prof. A Acquaviva) Sassari, Clinica Pediatrica (Prof. D Gallisai, Dr C Cosmi) Torino, Clinica Pediatrica (Prof. E Madon, Dr E Barisone) Trieste, Clinica Pediatrica (Prof. P Tamaro, Dr. GA Zanazzo) Varese, Clinica Pediatrica (Prof. L Nespoli) Verona, Clinica Pediatrica (Dr P Marradi)