M P Link

Stanford University, Palo Alto, California, United States

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Publications (93)1069.57 Total impact

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    ABSTRACT: Significant predictors of treatment outcome are poorly defined for patients with T-lineage acute lymphoblastic leukemia (T-ALL). A high WBC at diagnosis, which has traditionally been a predictor of poor response in T-ALL, has considerably weakened prognostic significance in the face of modern, more intensive chemotherapy. To test the hypothesis that bone marrow stroma-supported leukemic cell recovery might identify children at high risk for relapse, we measured the ex vivo recovery of T-ALL lymphoblasts from 29 newly diagnosed patients using a stromal cell co-culture assay. In all cases the T-ALL lymphoblasts showed an increase in recovery of T-ALL cells (RTC), ranging from 4 to 343%, in comparison to samples maintained without stroma. Since we were blinded to patient outcome in this case-control study, we then correlated patient outcome with RTC. The RTC for 18 patients in complete continuous remission (CCR) for greater than 4 years was stochastically larger than for the 11 patients who eventually relapsed (P = 0.011, by the two-sided Wilcoxon test). Furthermore, 100% of patients with an RTC of more than 26% had a CCR greater than 4 years while 78% of the patients with an RTC of less than 25% relapsed within 4 years. This is the first report to show that higher lymphoblast recovery may predict a more favorable outcome for children with T-ALL. A prospective study is needed to test whether stroma-supported leukemic cell recovery might serve as a basis for assigning risk-adjusted therapy.
    Leukemia 07/2002; 16(6):1121-6. · 10.16 Impact Factor
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    ABSTRACT: To identify which patients with rhabdomyosarcoma and microscopic residual disease (group II) are likely to not respond to therapy. Six hundred ninety-five patients with group II tumors received chemotherapy and 90% received radiation therapy on Intergroup Rhabdomyosarcoma Study (IRS)-I to IRS-IV (1972 to 1997). Tumors were subgrouped depending on the presence of microscopic residual disease only (subgroup IIa), resected positive regional lymph nodes, (subgroup IIb), or microscopic residual disease and resected positive regional lymph nodes (subgroup IIc). Overall, the 5-year failure-free survival rate (FFSR) was 73%, and patients with embryonal rhabdomyosarcoma treated on IRS-IV fared especially well (5-year FFSR, 93%; n = 90). Five-year FFSRs differed significantly by subgroup (IIa, 75% and n = 506; IIb, 74% and n = 101; IIc, 58% and n = 88; P = .0037) and treatment (IRS-I, 68%; IRS-II, 67%; IRS-III, 75%; IRS-IV, 87%; P < .001). Multivariate analysis revealed positive associations between primary site (favorable), histology (embryonal), subgroup IIa or IIb, treatment (IRS-III/IV), and better FFSRs. Patterns of treatment failure revealed local failure to be 8%, regional failure, 4%, and distant failure, 14%. The relapse pattern noted over the course of IRS-I to IRS-IV shows a decrease in the systemic relapse rates, particularly for patients with embryonal histology, suggesting that improvement in FFSRs is primarily a result of improved chemotherapy. Group II rhabdomyosarcoma has an excellent prognosis with contemporary therapy as used in IRS-III/IV, and those less likely to respond can be identified using prognostic factors: histology, subgroup, and primary site. Patients with embryonal rhabdomyosarcoma are generally cured, although patients with alveolar rhabdomyosarcoma or undifferentiated sarcoma, particularly subgroup IIc at unfavorable sites, continue to need better therapy.
    Journal of Clinical Oncology 10/2001; 19(20):4058-64. · 18.04 Impact Factor
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    ABSTRACT: Use of retroperitoneal lymph node dissection (RPLND) in paratesticular rhabdomyosarcoma (PTRMS) is controversial and has changed over the past 2 decades. The Intergroup Rhabdomyosarcoma Study Group (IRSG) required ipsilateral RPLND (IRPLND) for all patients with PTRMS treated on IRS-III (1984-91), but changed to clinical evaluation of RPLNs using computerized tomography (CT) in IRS-IV (1991 through 1997). In IRS-IV, only those patients with identified lymph node involvement on CT required surgical evaluation of the RPLNs. Nodal radiation therapy was administered only to patients with RPLNs recognized as positive; such patients received more intensive chemotherapy as well. Thus, they compared the incidence of recognized RPLN involvement using these 2 different approaches. They then analyzed patient outcome to determine whether this change in management affected outcome. Eligible patients with group I or II PTRMS who were treated on IRS III (n = 100) or IRS IV (n = 134) were analyzed. Failure-free survival (FFS) and survival (S) rates were estimated using the Kaplan-Meier method and compared using the log-rank test. There was a significant change in the distribution of patients with group I versus II tumors from IRS-III to IRS-IV (group I, 68% in IRS-III versus 82% in IRS-IV). This was the result of decreased node recognition when CT was used to stage RPLNs in IRS-IV and was most notable for adolescents (>10 years of age). Overall, 3-year FFS was 92% for patients treated on IRS-III and 86% for those treated on IRS-IV (P =.10), whereas survival estimates were 96% and 92%, respectively (P =.30). Adolescents were at higher risk of RPLN relapse than were children (<10 years of age) and their FFS and survival were worse, regardless of IRS protocol. Furthermore, adolescents with recognized group II tumors experienced better 3-year FFS than those with group I tumors on IRS-IV (100% versus 68%, P =.06), most likely as a result of receiving radiotherapy and intensified chemotherapy. Use of only CT scan evaluation of RPLN in IRS-IV led to a decrease in identification of RPLN involvement in boys who present with localized PTRMS, and a higher rate of regional relapse as compared with IRS-III. Adolescents had much higher likelihood of RPLN disease, and they fared significantly worse than did younger children on both studies. Furthermore, adolescent boys with group I tumors experienced worse FFS than those with Group II tumors on IRS-IV, probably because some patients with group II tumors were not identified by CT imaging and thus received less effective therapy. These data suggest that adolescents should have ipsilateral RPLN dissection as part of their routine staging, and those with positive lymph nodes require intensified chemotherapy as well as nodal irradiation.
    Seminars in Pediatric Surgery 09/2001; 10(3):146-52. · 2.40 Impact Factor
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    ABSTRACT: Factors affecting outcome for rhabdomyosarcoma (RMS) of the female genital tract in patients treated on Intergroup Rhabdomyosarcoma Study Group (IRSG) protocols I-IV were evaluated to define optimal therapy. Records of 151 patients with tumors of the female genital tract who were treated on IRSG protocols I-IV were reviewed for details regarding chemotherapy, surgery, radiotherapy (RT), and outcome. The overall 5-year survival was 82%, (87% for patients with locoregional tumors). Chemotherapy was primarily vincristine, actinomycin-D, and cyclophosphamide (VAC) based. Local therapy was surgery alone in 42% of patients, surgery plus RT in 19% of patients, biopsy plus RT in 12% of patients, and biopsy without RT in 21% of patients. The rate of hysterectomy decreased from 48% in IRS-I/II to 22% in IRS-III/IV with an increase in the use of RT from 23% in IRS-II to 45% in IRS-IV and continued excellent survival. Many patients with vaginal primary tumors received delayed RT or had it omitted on later studies with excellent outcome. For patients with localized embryonal/botryoid tumors, there were no significant differences in 5-year survival among patients with tumors at different sites or among patients treated on IRS-I-IV. In patients with Group I-III tumors, 43% of deaths were from toxicity. Analysis of prognostic factors, with toxic deaths censored, revealed that an age of 1-9 years at the time of diagnosis, noninvasive tumors, and the use of IRS-II or IRS-IV treatments were associated significantly with better outcome. Patients ages 1-9 years fared best (5-year survival of 98%) and patients outside of this age range especially benefited from the intensified therapy used in IRS-III or IRS-IV (5-year survival of 67% on the IRS-I/II vs. 90% in IRS-III/IV). Localized female genital RMS usually is curable with combination chemotherapy, a conservative surgical approach, and the use of RT for selected patients.
    Cancer 07/2001; 91(12):2454-68. · 5.20 Impact Factor
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    ABSTRACT: To further define the cytogenetic differences between B-cell lineage (B-lineage) acute lymphoblastic leukemia (ALL) and T-cell lineage ALL (T-ALL) and to determine the prognostic value of cytogenetics in childhood T-ALL, the blast cell karyotypes of 343 cases of pediatric T-ALL, the largest series reported to date, were evaluated. Cytogenetics were performed in a single central laboratory, and the children were treated using a single Pediatric Oncology Group protocol. Clear differences between the karyotypic characteristics of B-lineage ALL and T-ALL were confirmed. This study suggests that there may be survival differences associated with some T-ALL blast cell karyotypes. Better survival is associated with only normal karyotypes and with t(10;14) (translocation of chromosomes 10 and 14); worse survival is associated with the presence of any derivative chromosome. Two new recurring chromosome aberrations previously not reported in T-ALL were found: del(1)(p22) and t(8;12)(q13;p13). Ten aberrations found in this series, which were reported only once previously in T-ALL, can now be considered recurring abnormalities in T-ALL. All 12 of these new recurring aberrations are targets for discovery and characterization of new genes that are important in T-cell development and leukemogenesis.
    Blood 11/2000; 96(7):2543-9. · 9.78 Impact Factor
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    ABSTRACT: To compare failure-free survival (FFS) and survival for patients with local or regional embryonal rhabdomyosarcoma treated on the Intergroup Rhabdomyosarcoma Study (IRS)-IV with that of comparable patients treated on IRS-III. Patients were retrospectively classified as low- or intermediate-risk. Low-risk patients were defined as those with primary tumors at favorable sites, completely resected or microscopic residual, or orbit/eyelid primaries with gross residual disease and tumors less than 5 cm at unfavorable sites but completely resected. Intermediate-risk patients were all other patients with local or regional tumors. Three-year FFS improved from 72% on IRS-III to 78% on IRS-IV for patients with intermediate-risk embryonal rhabdomyosarcoma (P =.02). Subset analysis revealed two groups that benefited most from IRS-IV therapy. FFS at 3 years for patients with resectable node-positive or unresectable (group III) embryonal rhabdomyosarcoma arising at certain favorable sites (head and neck [not orbit/eyelid or parameningeal] and genitourinary [not bladder or prostate]) improved from 72% on IRS-III to 92% on IRS-IV (P =.01). Similarly, 3-year FFS for patients with completely resected tumor or with only microscopic disease remaining (group I or II) at unfavorable sites improved from 71% on IRS-III to 86% on IRS-IV (P =.04). Only patients with unresectable embryonal rhabdomyosarcoma (group III) at unfavorable sites had no improvement in outcome on IRS-IV (3-year FFS for IRS-III and IRS-IV, 72% and 75%, respectively; P =.31). IRS-IV therapy benefited certain subgroups of patients with intermediate-risk embryonal rhabdomyosarcoma. A doubling of the intensity of cyclophosphamide (or ifosfamide equivalent) dosing per cycle between IRS-III and IRS-IV is thought to be a key contributing factor for this improvement.
    Journal of Clinical Oncology 07/2000; 18(12):2427-34. · 18.04 Impact Factor
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    ABSTRACT: Contemporary chemotherapy has significantly improved event-free survival among patients with T cell-lineage acute lymphoblastic leukemia (T-ALL). Unlike B-precursor ALL, most investigators are still using cranial radiation (CRT) and are hesitant to rely solely on intrathecal therapy for T-ALL. In this study we assessed the effects of CRT upon event-free survival and central nervous system (CNS) relapses in a cohort of children with high risk features of T cell leukemia. In a series of six consecutive studies (1987-1995) patients were non-randomly assigned their CNS prophylaxis per individual protocol. These protocols were based on POG 8704 which relied on rotating drug combinations (cytarabine/cyclophosphamide, teniposide/Ara-C, and vincristine/doxorubicin/6-MP/prednisone) postinduction. Modifications such as high-dose cytarabine, intermediate-dose methotrexate, and the addition of G-CSF, were designed to give higher CNS drug levels (decreasing the need for CRT), to eliminate epidophyllotoxin (decreasing the risk of secondary leukemia), and to reduce therapy-related neutropenia (pilot studies POG 9086, 9295, 9296, 9297, 9398). All patients included in this analysis qualified for POG high risk criteria, WBC >50000/mm3 and/or CNS leukemia. Patients without CNS involvement received 16 doses of age-adjusted triple intra-thecal therapy (TIT = hydrocortisone, MTX, and cytarabine) whereas patients with CNS disease received three more doses of TIT during induction and consolidation. Patients who received CRT were treated with 2400 cGy (POG 8704) or 1800 cGy (POG 9086 and 9295). CNS therapy included CRT in 144 patients while the remaining 78 patients received no radiation by original protocol design. There were 155 males and 57 females with a median age of 8.2 years. The median WBC for the CRT+ and CRT- patients were 186000/mm3 and 200000/mm3, respectively. CNS involvement at diagnosis was seen in 16% of the CRT+ and 23% of the CRT- groups. The complete continuous remission rate (CCR) was not significantly different for the irradiated vs. non-irradiated groups (P = 0.46). The 3-year event-free survival was 65% (s.e. 6%) and 63% (s.e. 4%) for the non-irradiated vs. the radiated group. However, the 3-year CNS relapse rate was significantly higher amongst patients who did not receive CRT; 18% (s.e. 5%) vs. 7% (s.e. 3%) in the irradiated group (P = 0.012). Our analysis in a non-randomized setting, suggests that CRT did not significantly correlate with event-free survival but omitting it had an adverse effect on the CNS involvement at the time of relapse.
    Leukemia 03/2000; 14(3):369-73. · 10.16 Impact Factor
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    ABSTRACT: The treatment of primary lymphoma of bone (PLB) in children has traditionally included radiotherapy to the primary site; more recently, it has included systemic chemotherapy. Because of concern about the untoward effects of treatment in a disease that is curable, we attempted to determine whether radiotherapy can be safely excluded from treatment. The results of three consecutive Pediatric Oncology Group (POG) studies were examined to determine the impact on outcome of radiotherapy as adjunctive treatment in children and adolescents receiving chemotherapy for early-stage primary lymphoma of bone. From 1983 to 1997, 31 patients with localized PLB were entered onto POG studies of early-stage non-Hodgkin's lymphoma (NHL). Between 1983 and 1986, seven patients were treated with 8 months of chemotherapy with irradiation (XRT) of the primary site. After 1986, patients were treated without XRT; four received 8 months of chemotherapy, and 20 received 9 weeks of chemotherapy. Primary sites were the femur (nine), tibia (eight), mandible (five), mastoid (one), maxilla (one), zygomatic arch (one), rib (one), clavicle (one), scapula (one), ulna (one), talus (one), and calcaneous (one). Histologic classification revealed 21 cases of large cell lymphoma, five cases of lymphoblastic lymphoma, two cases of small, noncleaved-cell lymphoma, and three cases of NHL that could not be classified further. One patient relapsed at a distant site 22 months after completion of therapy. There have been no deaths. Localized PLB is curable in most children and adolescents with a 9-week chemotherapy regimen of modest intensity, and radiotherapy is an unnecessary adjunct.
    Journal of Clinical Oncology 03/1999; 17(2):456-9. · 18.04 Impact Factor
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    ABSTRACT: This study was designed to test the hypothesis that high-dose asparaginase consolidation therapy improves survival in pediatric patients with T cell acute lymphoblastic leukemia and advanced stage lymphoblastic lymphoma. Five hundred and fifty-two patients (357 patients with T cell acute lymphoblastic leukemia (ALL) and 195 patients with advanced stage lymphoblastic lymphoma) were enrolled in POG study 8704 (T-3). Treatment included rotating combinations of high-dose myelosuppressive chemotherapy agents proven to be effective in T cell ALL in other POG group-wide or local institutional protocols (including vincristine, doxorubicin, cyclophosphamide, prednisone, asparaginase, teniposide, cytarabine and mercaptopurine). After achieving a complete remission (CR), patients were randomized to receive or not receive high-dose intensive asparaginase consolidation (25,000 IU/m2) given weekly for 20 weeks by intramuscular injection. Intrathecal chemotherapy (methotrexate, hydrocortisone and cytarabine) was given to prevent CNS disease, and CNS irradiation was used only for patients with leukemia and an initial WBC of >50,000/microl or patients with active CNS disease at diagnosis. CR was achieved in 96% of patients. The high-dose asparaginase regimen was significantly superior to the control regimen for both the leukemia and lymphoma subgroups. Four-year continuous complete remission rate (CCR) for the leukemia patients was 68% (s.e. 4%) with asparaginase as compared to 55% (s.e. 4%) without. For the lymphoma patients, 4-year CCR was 78% (s.e. 5%) with asparaginase and 64% (s.e. 6%) in the controls. The overall one-sided logrank test had a P value <0.001 favoring asparaginase, while corresponding values were P = 0.002 for ALL and P = 0.048 lymphoblastic lymphoma. Toxicities were tolerable, but there were 18 failures due to secondary malignancies (16 with non-lymphocytic leukemia or myelodysplasia). Neither WBC at diagnosis (leukemia patients) nor lymphoma stage were major prognostic factors. We conclude that when added to a backbone of effective rotating agents, repeated doses of asparaginase during early treatment improve the outcome for patients with T cell leukemia and advanced stage lymphoblastic lymphoma.
    Leukemia 03/1999; 13(3):335-42. · 10.16 Impact Factor
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    ABSTRACT: To determine the molecular characteristics, clinical features, and treatment outcomes of children with acute lymphoblastic leukemia (ALL) and the t(11;19)(q23,p13.3) translocation. A retrospective analysis of leukemic cell karyotypes obtained from patients with new diagnoses of ALL who were treated at St. Jude Children's Research Hospital or by the Pediatric Oncology Group was performed to identify cases with the t(11;19)(q23;p13.3) translocation. Molecular analyses were performed on these cases to determine the status of the MLL gene and the presence of the MLL-ENL fusion transcript. Among 3,578 patients with ALL and successful cytogenetic analysis, we identified 35 patients with the t(11;19)(q23;p13.3) translocation: 13 infants and 11 older children had B-precursor leukemia, whereas 11 patients had a T-cell phenotype. Although all of the cases examined had MLL rearrangements and MLL-ENL fusion transcripts, outcome varied according to age and immunophenotype. Among B-precursor cases, only two of the 13 infants remain in complete remission, compared with six of the 11 older children. Most strikingly, no relapses have occurred among B-precursor patients 1 to 9 years of age or among T-cell patients. Although MLL gene rearrangements are generally associated with a dismal outcome in ALL, two distinct subsets with MLL-ENL fusions have an excellent prognosis. Our results suggest that patients with this genetic abnormality who have T-cell ALL or are 1 to 9 years of age should not be considered candidates for hematopoietic stem-cell transplantation during their first remission.
    Journal of Clinical Oncology 02/1999; 17(1):191-6. · 18.04 Impact Factor
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    ABSTRACT: Five pediatric patients are described with acute lymphoblastic leukemia (ALL) who at presentation had clinical findings suggestive of B cell ALL and lymphoblasts with FAB L3 morphology and the characteristic t(8;14)(q24;q32). However, the leukemia cells of all five patients failed to express surface immunoglobulin (sIg) and kappa or lambda light chains. Based on initial immunophenotyping results consistent with B-precursor ALL, four of these cases were initially treated with conventional ALL chemotherapy. These four patients were switched to B cell ALL treatment protocols once cytogenetic results became available revealing the 8;14 translocation. The fifth case was treated with B cell ALL therapy from the outset. Four of the five patients are in complete remission at 64, 36, 29 and 13 months from diagnosis. One patient relapsed and died 6 months after initial presentation. These five unusual cases with clinical B cell ALL, the t(8;14), and FAB L3 morphology, but negative sIg, demonstrate the importance of careful and multidisciplinary evaluation of leukemic cells with morphology, cytochemistry, immunophenotyping and cytogenetic analysis. Future identification of patients with this profile will allow us to expand our knowledge regarding prognostic significance and optimal treatment for this rare subgroup of patients.
    Leukemia 02/1999; 13(1):135-41. · 10.16 Impact Factor
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    ABSTRACT: To estimate the duration of survival (S) of patients with metastatic osteosarcoma (MOS) at diagnosis treated with a multiagent, ifosfamide-containing chemotherapeutic and surgical regimen and to evaluate the toxicity of this regimen. Thirty patients aged younger than 30 years received two courses of ifosfamide followed by surgery on the primary tumor and metastatic sites. Patients then received a postsurgical multiagent chemotherapeutic regimen that consisted of high-dose methotrexate (HDMTX), ifosfamide, doxorubicin, and cisplatin. The 5-year event-free survival (EFS) rate was 46.7% (95% confidence interval [CI]; 28.5 to 64.9) and 5-year S rate was 53.3% (95% CI; 35.1 to 71.5). Three patients with bone metastases and one patient with lymph node metastases died. Twenty-six patients presented with pulmonary metastatic nodules only. Eight of these patients had at least eight nodules at diagnosis and had an estimated 5-year EFS rate of 25.0% compared with 66.7% for the 18 patients with less than eight nodules (P=.06). Fourteen patients presented with bilateral lung metastases and had a 5-year EFS rate of 35.7% compared with the 12 patients who presented with unilateral involvement and had a 5-year EFS rate of 75.0% (P=.03). The hematopoietic toxicity experienced by the patients during the entire regimen was relatively mild. Seven patients had renal toxicity characterized by hypophosphatemia and/or hypokalemia. This ifosfamide-containing regimen is tolerable and effective in the treatment of patients with osteosarcoma (OS) who present with lung metastases. However, better regimens are required for this group of patients.
    Journal of Clinical Oncology 12/1998; 16(11):3641-8. · 18.04 Impact Factor
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    ABSTRACT: To determine if involved field radiation (IF) is equivalent to standard whole bone radiation (SF) in local tumor control; to establish patterns of failure following treatment; and to determine response, event-free survival (EFS), and overall survival rates from multidisciplinary therapy in Ewing's sarcoma. Between 1983 and 1988, 184 children with Ewing's sarcoma were enrolled onto Pediatric Oncology Group 8346 (POG 8346). A total of 178 (97%) met eligibility criteria; 6 had pathology other than Ewing's sarcoma. Induction chemotherapy of cyclophosphamide/doxorubicin (adriamycin )(C/A) x 12 weeks was followed by local treatment either surgery or radiation therapy and C/A, dactinomycin, and vincristine for 50 weeks. Resection was advised for patients with small primary tumors if accomplished without functional loss. Forty patients were randomized to receive SF, whole bone radiation to 39.6 Gy plus a 16.2 Gy boost (total 55.8 Gy) or IF to 55.8 Gy, and the remainder were assigned to IF radiation. Of 178 eligible patients, 141 (79%) had localized disease and 37 (21%) had metastases at presentation. Their 5-year EFS was 51% (SE 5%) and 23% (SE 7%) respectively. The response rate to induction chemotherapy was 88% (28% complete, 60% partial), but after radiotherapy the response rate increased to 98%. Thirty-seven of the localized patients underwent resection, of whom 16 (43%) required postoperative radiotherapy; the 5-year EFS of these surgical patients was 80% (SE 7%). The remaining 104 localized patients were eligible for randomization or assignment to receive radiotherapy; the 5-year EFS of these patients was 41% (SE 5%), with no significant difference in EFS between those randomized to SF vs. IF. Site of primary tumor correlated with 5-year EFS: distal extremity 65% (SE 8%), central 63% (SE 10%), proximal extremity 46% (SE 8%), and pelvic-sacral 24% (SE 10%) (p=0.004). Initial tumor size did not correlate significantly with EFS. Patterns of failure among the 141 localized patients revealed 23% of patients experienced a local failure, while 40% had a systemic failure. The 5-year local control rate for the surgical patients +/- postoperative radiotherapy was 88% (SE 6%), while for the patients undergoing radiotherapy alone it was 65% (SE 7%). There was no difference in local control between those randomized to SF vs. IF. The 5-year local control rate for the patients with pelvic-sacral tumors was 44% (SE 15%), significantly worse than the local control rates for those with central tumors 82% (SE 8%), distal extremity 80% (SE 8%), or proximal extremity 69% (SE 9%) (p=0.023). However, quality of radiotherapy correlated with outcome. Patients who had appropriate radiotherapy had a 5-year local control of 80% (SE 7%), while those with minor deviations had 5-year local control of 48% (SE 14%), and those with major deviations had a local control of only 16% (SE 15%) (p=0.005). The local failure was within an irradiated volume in 62% of patients, outside the irradiated volume in 24% of cases, while the precise location could not be determined in the remaining 14%. As most failures in Ewing's sarcoma are systemic, improved EFS requires more effective systemic chemotherapy. Adequate IF radiotherapy requires treatment to appropriate volumes as defined by MRI imaging and full radiation doses. Pretreatment review of radiologic images with a musculoskeletal radiologist to determine appropriate tumor volumes, as well as use of conformal radiotherapy techniques are important for improved outcome.
    International Journal of Radiation OncologyBiologyPhysics 09/1998; 42(1):125-35. · 4.52 Impact Factor
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    ABSTRACT: A t(1;19)(q23;p13) is detected cytogenetically in approximately 5% of childhood acute lymphoblastic leukemias (ALLs) and its presence has been associated with an increased risk of relapse in several previously-completed Pediatric Oncology Group (POG) clinical trials. The t(1;19) fuses E2A to PBX1 in more than 95% of cases and this molecular abnormality can be reliably identified by polymerase chain reaction (PCR)-mediated amplification of E2A-PBX1 chimeric mRNAs. We used a nested PCR assay, which reproducibly detected a 10(4)- to 10(5)-fold dilution of t(1;19)+ into t(1;19)- cells, to evaluate minimal residual disease (MRD) in 48 children with t(1;19)+ ALL enrolled in POG clinical trials for lower (POG 9005) and higher (POG 9006) risk ALL. Peripheral blood (PB) and bone marrow (BM) samples were collected prospectively at the end of consolidation (weeks 25 and 31 after end of induction) and the presence or absence of PCR-detectable MRD was correlated with clinical outcome. Overall, 41 of 148 (28%) samples were PCR+. Of the 65 time points with informative results from both PB and BM, PCR results were concordant for 51 pairs (10 PB+/BM+, 41 PB-/ BM-) and discordant for 14 (5 PB+/BM-, 9 PB-/BM+), indicating that assessment of only PB or only BM can inaccurately classify some PCR+ cases as PCR-. There were no significant differences in event-free survival between PCR+ and PCR- patients. We conclude that qualitative detection of MRD by amplification of E2A-PBX1 chimeric mRNAs at the end of consolidation was not significantly predictive of outcome for children treated on POG 9005/9006 and that such results should not be used to alter therapy for patients with t(1;19)+ ALL.
    Blood 03/1998; 91(3):1021-8. · 9.78 Impact Factor
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    ABSTRACT: The Pediatric Oncology Group (POG) conducted a two-arm, randomized study for the treatment of children and adolescents with stage III small, non-cleaved cell lymphoma (SNCCL). Regimen A, based on the group's previous best treatment for this group of patients, included cyclophosphamide (CTX) and high-dose methotrexate (MTX), as well as vincristine (VCR), prednisone (PRED), and intrathecal (IT) chemoprophylaxis. Regimen B, based on a single institution pilot study (Total B therapy), consisted of two rapidly alternating chemotherapy combinations (CTX, VCR, doxorubicin; MTX, and cytarabine (Ara-C) plus coordinated IT chemotherapy. One hundred thirty-four consecutive patients were entered on this study. Seventy patients were randomized to Regimen A, and 64 patients to Regimen B. One hundred and twenty-two patients are eligible for response. Complete remission (CR) was achieved by 81% (52/64) of patients on Regimen A, and 95% (55/58) of patients on Regimen B (p=0.014 one-sided). The two-year event-free survival (EFS) is 64% (SE=6%) on Regimen A, and 79% (SE=6%) on Regimen B (p=0.027 by one-sided logrank test). No patient has relapsed on either regimen after a year from diagnosis, although one patient had a second malignancy at day 371. Severe, but manageable, hematologic toxicity was seen in the majority of patients on both regimens, but was more frequent on Regimen B. We conclude that the cure rate in stage III SNCCL is significantly improved with the use of a short, six-month chemotherapy regimen of fractionated CTX alternated with coordinated MTX and Ara-C. Results suggest that drug schedule, not simple drug selection, influences outcome.
    Medical and Pediatric Oncology 01/1998; 29(6):526-33.
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    ABSTRACT: Children and young adults with early-stage non-Hodgkin's lymphoma have an excellent prognosis, but treatment is prolonged and is associated with many side effects. We performed two studies to determine whether therapy could be simplified. Between 1983 and 1991, we conducted two consecutive trials in children and young adults (age, <21 years) with early-stage non-Hodgkin's lymphoma. In the first trial, patients were treated for 9 weeks with induction chemotherapy consisting of vincristine, doxorubicin, cyclophosphamide, and prednisone, followed by 24 weeks of continuation chemotherapy with mercaptopurine and methotrexate. Half the patients were randomly assigned to receive involved-field irradiation. In the second trial, after the 9 weeks of induction chemotherapy, the patients were randomly assigned to receive 24 weeks of continuation chemotherapy or no further therapy. A total of 340 patients were enrolled in the two trials, 12 of whom did not have complete remissions. One hundred thirteen patients received nine weeks of chemotherapy without radiotherapy, 131 received eight months of chemotherapy without radiotherapy, and 67 received eight months of chemotherapy with radiotherapy. At five years, the projected rates of continuous complete remission were 89, 86, and 88 percent for the three groups, respectively. At five years, event-free survival among the patients with early-stage lymphoblastic lymphoma was inferior to that among the patients with other subtypes of lymphoma (63 percent vs. 88 percent, P<0.001). Continuation therapy was effective only in patients with lymphoblastic lymphoma. A nine-week chemotherapy regimen without irradiation of the primary sites of involvement is adequate therapy for most children and young adults with early-stage, nonlymphoblastic non-Hodgkin's lymphoma.
    New England Journal of Medicine 11/1997; 337(18):1259-66. · 51.66 Impact Factor
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    ABSTRACT: Acute lymphoblastic leukemia (ALL) occurring in infants less than 1 year of age differs clinically and biologically from that observed in older children. Cytogenetically, 11q23 translocations are detected in approximately 50% of infant ALLs and fuse the 11q23 gene HRX with a variety of partner chromosomal loci. Overall, HRX rearrangements are detected molecularly in 70-80% of infant ALLs as compared to 5-7% of ALLs arising in older children. Two recently described molecular abnormalities in childhood ALL are ETV6 gene rearrangements and homozygous deletions of p16(INK4A) and/or p15(INK4B). Each of these abnormalities occurs in 15-20% of all childhood ALLs, and neither can be accurately identified by routine cytogenetic analyses. The incidence of these genetic abnormalities and their potential relationship to HRX gene status in infant ALL is unknown. Using Southern blot analyses, we determined ETV6 and p16(INK4A)/p15(INK4B) gene status in a cohort of infant ALLs. No ETV6 rearrangements or homozygous deletions (n=69) or homozygous p16(INK4A) and/or p15(INK4B) gene deletions (n=54) were detected in any of the infant ALLs. Therefore, ETV6 and p16(INK4A)/p15(INK4B) do not play a significant role in the pathogenesis of infant ALL, further emphasizing the distinctive biology of this subset of leukemias.
    Leukemia 08/1997; 11(7):979-83. · 10.16 Impact Factor
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    ABSTRACT: To determine whether potential alteration in p53 function through p53 gene mutation or mdm-2 overexpression correlates with early treatment failure in childhood acute lymphoblastic leukemia (ALL). Diagnostic marrow samples from 34 children were analyzed for p53 gene alterations by western blot and SSCP/DNA sequence analysis and for mdm-2 overexpression by western blot analysis. These samples were derived from two groups of children with ALL: 17 good outcome patients who are in long-term continuous complete remission and 17 poor outcome patients who did not achieve a complete remission or relapsed within 6 months of achieving remission. Two children within the poor outcome group were found to have p53 gene mutations. Furthermore, five poor outcome patients were shown to have greater than 10-fold overexpression of mdm-2 protein compared with the mean level of mdm-2 protein measured in the good outcome group. Aberrant p53 protein expression was found in only one good outcome patient, whereas no good outcome children were found to have elevated levels (> 10-fold) of mdm-2 protein. We show for the first time that potential alteration in p53 function in childhood ALL is more common (P = .036) in cases of early treatment failure than in children who remain in long-term continuous remission.
    Journal of Clinical Oncology 04/1997; 15(3):1158-62. · 18.04 Impact Factor
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    ABSTRACT: Frequent deletion of chromosome 9p21 in many cancers has suggested the presence of tumor suppressor genes in this region. Two genes mapping to 9p21, p15 and p16, encode inhibitors for cyclin-dependent kinases 4 and 6. We recently found that in T-cell acute lymphoblastic leukemia (T-ALL), both the p15 and p16 genes are deleted at a high frequency, with p16 gene deletion occurring slightly more frequently than p15 gene deletion. We now show that in addition to deletion, the p15 gene is preferentially hypermethylated at a 5' CpG island, which has been shown previously to be associated with loss of transcription of this gene. The p15 gene was methylated in 38% (17 of 45) of T-ALL patients at diagnosis and in 22% (7 of 32) of patients at relapse. On the other hand, methylation of the p16 gene was a rare event, occurring in 4% (2 of 49) of patients at diagnosis and in none (0 of 30) at relapse. The overall rates of alteration occurring in at least one allele of the p15 gene is 84% at diagnosis and 88% at relapse. These rates are as high as, if not greater than, those for the p16 gene (80% at diagnosis and 74% at relapse). In fact, such alterations involve both alleles in the majority of samples: 76% for p15 and 67% for p16 at diagnosis. All together, more than one-half (56%) of T-ALL samples harbor alterations in both alleles of both p15 and p16. These results lend strong support for a role of both p15 and p16 as tumor suppressors in T-ALL.
    Cancer Research 04/1997; 57(5):832-6. · 8.65 Impact Factor
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    ABSTRACT: TEL gene rearrangement is the most common genetic lesion in pediatric acute lymphoblastic leukemia (ALL), occurring in about 25% of B-lineage cases. We previously showed that, among patients treated on St Jude protocols, TEL rearrangement independently conferred an excellent prognosis. To extend these results to patients treated with antimetabolite-based therapy, we performed Southern blot analysis to determine the TEL gene status of 104 cases of B-lineage ALL treated on Pediatric Oncology Group 8602, matched on age, gender, and leukocyte count. There were 52 failures among the 77 patients with germline TEL, compared with only 8 failures among 27 patients in the rearranged group. Based on a two-sided logistic regression analysis, stratified for age (subdivided at 10 years), leukocyte count (subdivided at 50,000), and gender, the estimated odds of failing by 4 years in the germline TEL group is 5.4 times that of the rearranged TEL group, with 95% confidence from 1.9 to 15.6, two-sided P = .0009. Thus, the presence of a rearranged TEL gene is also associated with an improved survival among patients treated with antimetabolite-based therapy. Our results indicate that all newly diagnosed ALL patients should be screened for TEL gene rearrangements and suggest that these patients are candidates for less intensive therapy.
    Blood 03/1997; 89(4):1143-6. · 9.78 Impact Factor

Publication Stats

3k Citations
1,069.57 Total Impact Points

Institutions

  • 1988–2001
    • Stanford University
      • • Department of Pediatrics
      • • Department of Medicine
      • • Department of Pathology
      Palo Alto, California, United States
  • 1998
    • Hackensack University Medical Center
      Hackensack, New Jersey, United States
    • University of Colorado
      • Department of Pediatrics
      Denver, CO, United States
  • 1986–1998
    • Roswell Park Cancer Institute
      • Department of Pediatrics
      Buffalo, New York, United States
    • Southwest Foundation For Biomedical Research
      San Antonio, Texas, United States
  • 1997
    • St. Jude Children's Research Hospital
      • Department of Pharmaceutical Sciences
      Memphis, TN, United States
  • 1994
    • Johns Hopkins Medicine
      • Department of Pathology
      Baltimore, MD, United States
  • 1991–1993
    • Dana-Farber Cancer Institute
      Boston, Massachusetts, United States
  • 1992
    • University of Washington Seattle
      • Division of Medical Genetics
      Seattle, WA, United States
    • Lucile Packard Children’s Hospital at Stanford
      Palo Alto, California, United States
  • 1984–1992
    • Stanford Medicine
      • • Department of Pediatrics
      • • Department of Medicine
      Stanford, CA, United States