Long-term analysis of children with metastatic neuroblastoma treated in the ENSG5 randomised clinical trial.

BACKGROUND: The European Neuroblastoma Study Group 5 (ENSG5) trial showed that time-intensive "rapid" induction chemotherapy (COJEC) was superior to "standard" 3-weekly chemotherapy for children with high-risk metastatic neuroblastoma. Long-term outcomes of the ENSG5 trial were analysed. PROCEDURE: Patients with metastatic neuroblastoma aged ≥12 months were randomly assigned to "standard" or "rapid" induction, receiving the same chemotherapy drugs and doses. Event-free survival (EFS) and overall survival (OS) were analysed and prognostic factors evaluated. Amongst patients surviving >5 years, a population of children with persistent metastatic disease after the end of treatment was identified and described. RESULTS: Ten-year EFS was 18.2% (95% confidence interval: 12.2-25.2) for the "standard" arm and 26.8% (19.5-34.7) for the "rapid" arm (hazard ratio [HR] 0.85, P = 0.28). Ten-year OS for the "standard" arm was 19.7% (13.4-26.8) and 28.3% (20.8-36.2) for the "rapid arm" (HR 0.83, P = 0.19). There was a trend for worse EFS and OS for patients having MYCN amplification (HR 1.37 and 1.40, respectively) and those with partial and mixed response to induction (HR 1.69 and 1.75 for EFS and 1.66 and 2.00 for OS, respectively). Among 69 patients who survived >5 years, six had persistent metastatic disease after the end of treatment. CONCLUSION: The benefit of the "rapid" induction regimen seems to be maintained in the long term, although the small number of survivors could justify the lack of statistical significance. MYCN amplification and poor metastatic response to induction could be associated with worse outcomes. A small group of patients with persistent metastatic disease that survived long term has been described.

Ewing Sarcoma: Current Management and Future Approaches Through Collaboration.

Ewing sarcoma (ES) is an aggressive sarcoma of bone and soft tissue occurring at any age with a peak incidence in adolescents and young adults. The treatment of ES relies on a multidisciplinary approach, coupling risk-adapted intensive neoadjuvant and adjuvant chemotherapies with surgery and/or radiotherapy for control of the primary site and possible metastatic disease. The optimization of ES multimodality therapeutic strategies has resulted from the efforts of several national and international groups in Europe and North America and from cooperation between pediatric and medical oncologists. Successive first-line trials addressed the efficacy of various cyclic combinations of drugs incorporating doxorubicin, vincristine, cyclophosphamide, ifosfamide, etoposide, and dactinomycin and identified prognostic factors now used to tailor therapies. The role of high-dose chemotherapy is still debated. Current 5-year overall survival for patients with localized disease is 65% to 75%. Patients with metastases have a 5-year overall survival < 30%, except for those with isolated pulmonary metastasis (approximately 50%). Patients with recurrence have a dismal prognosis. The many insights into the biology of the EWS-FLI1 protein in the initiation and progression of ES remain to be translated into novel therapeutic strategies. Current options and future approaches will be discussed.

Geographical Factors Affecting the Admission of Teenagers and Young Adults to Age-Specialist Inpatient Cancer Care in England.

Purpose: Little is known about the factors that influence the place of inpatient care for teenage and young adult (TYA) cancer patients. Recent guidelines have recommended centralization of care for this group to a small number of specialized centers. This study aimed to investigate the influence of geography and travel times on the likelihood of admission to an age-specialist center in England during cancer treatment for patients aged 15-24 at the time of diagnosis. Methods: Data for 6788 patients aged 15-24, diagnosed between 2001 and 2006 and treated as an inpatient in England between 2001 and 2009, were obtained from the National Cancer Data Repository. Eight TYA age-specialist centers were identified in England during this time period; road travel times to these centers were calculated using ArcGIS Network Analyst. Factors thought to affect the likelihood of admission, such as diagnostic group, gender, and age at diagnosis were modeled using logistic regression. Results: Overall, 66.9% of patients never received inpatient treatment at a TYA age-specialist center during the course of their treatment. Increasing travel time significantly reduced the likelihood of admission to a TYA age-specialist center after adjustment for case mix factors. Conclusion: Many TYA patients received little or no inpatient treatment at a TYA age-specialist center during their treatment. The variation between diagnostic groups suggests that factors other than distance to the closest center are affecting the likelihood of admission and demonstrates the potential need to consider improvements to the structured referral practice for this unique group of patients.

Long-term follow-up of children with high-risk neuroblastoma: the ENSG5 trial experience.

BACKGROUND: Therapy for high-risk neuroblastoma is intensive and multimodal, and significant long-term adverse effects have been described. The aim of this study was to identify the nature and severity of late complications of metastatic neuroblastoma survivors included in the ENSG5 clinical trial. PROCEDURE: The trial protocol included induction chemotherapy (randomized "Standard" OPEC/OJEC vs. "Rapid" COJEC), surgery of primary tumor and high-dose melphalan with stem cell rescue. Two hundred and sixty-two children were randomized, 69 survived >5 years, and 57 were analyzed. Data were obtained from the ENSG5 trial database and verified with questionnaires sent to participating centers. RESULTS: Median follow-up was 12.9 (6.9-16.5) years. No differences were found in late toxicities between treatment arms. Twenty-eight children (49.1%) developed hearing loss. Nine patients (15.8%) developed glomerular filtration rate <80 ml/min/1.73 m(2), but no cases of chronic renal failure were documented. Endocrine complications (28.1% of children) included mainly hypogonadism and delayed growth. Four children developed second malignancies, three of them 5 years after diagnosis: one osteosarcoma, one carcinoma of the parotid gland and one ependymoma. There were no hematological malignancies or deaths in remission. CONCLUSIONS: This study analyzed a wide cohort of high-risk neuroblastoma survivors from a multi-institutional randomized trial and established the profile of long-term toxicity within the setting of an international clinical trial.

Presence of chemotherapy-induced toxicity predicts improved survival in patients with localised extremity osteosarcoma treated with doxorubicin and cisplatin: a report from the European Osteosarcoma Intergroup.

AIM: Chemotherapy-induced toxicity is an independent prognostic indicator in several cancers. We aimed to determine whether toxicity was related to survival and histological response in high-grade localised extremity osteosarcoma. We undertook a retrospective analysis of patients treated within three consecutive randomised controlled trials (RCTs) of the European Osteosarcoma Intergroup. METHODS: Between 1982 and 2002, 533 patients were randomised to six cycles of doxorubicin 75 mg/m(2) and cisplatin 100 mg/m(2). Toxicity data were collected prospectively and graded according to the World Health Organisation (WHO) criteria. Standard univariate and multivariate models were constructed to examine the relationship between reported toxicity, survival, and histological response. RESULTS: Five- and 10-year overall survival was 57% (95% confidence interval (CI) 52-61%) and 53% (49-58%), respectively. Grades 3-4 oral mucositis (hazard ratio (HR) 0.51, 95% CI 0.29-0.91), grades 1-2 nausea/vomiting (HR 0.37, 95% CI 0.16-0.85), grades 1-2 thrombocytopenia (HR 0.49, 95% CI 0.27-0.87), good histological response (HR 0.42, 95% CI 0.27-0.65), and distal tumour site (HR 0.45, 95% CI 0.28-0.71) were associated with improved survival in multivariate analysis. The only factors that were independently associated with histological response were older age (odds ratio (OR) 0.18, 95% CI 0.04-0.72) and chondroblastic tumour (OR 0.28, 95% CI 0.10-0.77), both being associated with a significantly lower chance of achieving a good response. CONCLUSION: Chemotherapy-induced toxicity predicts survival in patients with localised extremity osteosarcoma. Investigation of the pharmacogenomic mechanisms of constitutional chemosensitivity underlying these observations will present opportunities for personalising treatment and could lead to improved outcomes.

Survival after recurrent osteosarcoma: data from 3 European Osteosarcoma Intergroup (EOI) randomized controlled trials.

BACKGROUND: Recurrence after osteosarcoma usually leads to death; thus prognostic factors for survival are of great importance. METHODS: Between 1983 and 2002, the European Osteosarcoma Intergroup accrued 1067 patients to 3 randomized controlled trials of pre- and post-operative chemotherapy for patients with resectable non-metastatic high-grade osteosarcoma of the extremity. Control treatment in all trials was doxorubicin 75 mg/m² and cisplatin 100mg/m². The comparators were additional high-dose methotrexate (BO02), T10-based multi-drug regimen (BO03) and G-CSF intensified-DC (BO06). Post-recurrence survival (PRS) was investigated on combined data with standard survival analysis methods. RESULTS: Median recurrence-free survival was 31 months; 8 recurrences were reported more than 5 years after the diagnosis. In 564 patients with a recurrence (median 13 months post-randomisation), there was no difference in post-relapse survival between treatment arms. Patients whose disease recurred within 2 years after randomization had a worse prognosis than those recurring after 2 years. Patients with good initial histological response to pre-operative chemotherapy had a better overall survival after recurrence than poor responders. Local relapse was more often reported after limb-saving procedures (2 versus 8%; amputation versus limb-saving), independent of the primary tumour site. Site of first recurrence (local 20%, lung 62%, "other" 19%) affected survival, as patients recurring with non-lung distant metastases only or any combination of local relapse, lung metastases and non-lung metastases (=group "other") had significantly worse overall survival (local 39%, lung 19%, "other" 9% at 5 years). CONCLUSIONS: These data describing a large series of patients with recurrent extremity osteosarcoma confirm the relationship between early recurrence and poor survival. There was better PRS in patients after good histological response to pre-operative chemotherapy, or with local-only recurrence.

Workshop Report on the European Bone Sarcoma Networking Meeting: Integration of Clinical Trials with Tumor Biology.

A key workshop was held in The Netherlands in June 2011, hosted by several European bone sarcoma networks and with a broad range of stakeholders from Europe and Australia. The purpose of the meeting was to identify the strengths and weaknesses in current clinical trials for bone sarcomas and to make recommendations as to how to accelerate progress in this field. Two areas of particular interest were discussed. First, all participants agreed upon the importance of tumor biology to understanding clinical responses for all types of bone sarcoma. Various barriers to biobanking tumor and germline specimens were canvassed and are outlined in this paper. Second, there was consideration of the particular challenges of dealing with adolescent and young adult cancers, exemplified by bone sarcomas. Participants recommended greater engagement of both pediatric and adult sarcoma trial organizations to address this issue. Specific opportunities were identified to develop biological sub-studies within osteosarcoma, focused on understanding germ line risk and pharmacogenomics defining toxicity and biological responses. In Ewing sarcoma, it was harder to define opportunities for biological insights. There was agreement that the results for insulin-like growth factor pathway inhibition in Ewing family tumors were disappointing, but represented a clear indication of the need for companion biologic studies to develop predictive biomarkers. The meeting ended with broad commitment to working together to make progress in this rare but important subgroup of cancers.

Dose finding study for the use of subcutaneous recombinant interleukin-2 to augment natural killer cell numbers in an outpatient setting for stage 4 neuroblastoma after megatherapy and autologous stem-cell reinfusion.

PURPOSE: To establish a safe dose of subcutaneous (SC) recombinant interleukin 2 (rIL-2) in an outpatient setting for children with stage 4 neuroblastoma after megatherapy (MGT) and autologous stem-cell reinfusion (ASCR) that is able to sustain an increase of natural-killer cells (NKCs) above the level previously reported for immunomodulatory potency. PATIENTS AND METHODS: Between August 1997 and November 2000, 33 patients with stage 4 neuroblastoma entered the study from six countries after receiving MGT/ASCR according to national protocols. Dose levels of 3, 6, and 9 × 10(6) U rIL-2/m(2) were given SC in six 5-day cycles every 2 weeks. RESULTS: Median age at registration was 4.1 years (range, 1.8 to 7.4). Median observation time was 5 years (range, 4 to 9.8). Increase of NKCs was achieved in 89% of courses, with more than 100% increase over baseline and/or more than 1,000 NKCs/µL in 58%. On the basis of outpatient dose-limiting toxicity at dose level 3, dose level 2 was chosen for the confirmation stage. At dose level 2, the median increase in absolute NKCs was 1,180 cells/µL for all 83 cycles, corresponding to a median relative NKC increase over baseline of 711%. Fever was frequent but controllable with adequate supportive care; 6.5% of patients were hospitalized. Localized pain was moderate and acceptable. Event-free and overall survival rates at 5 years were 45% (± 9 standard deviation [SD]) and 48% (± 9 SD), respectively. CONCLUSION: The low toxicity profile and ability to sustain an increase in NKCs of IL-2 at 6 × 10(6) U/m(2) SC allows its integration in an outpatient setting.

Impact of EWS-ETS fusion type on disease progression in Ewing's sarcoma/peripheral primitive neuroectodermal tumor: prospective results from the cooperative Euro-E.W.I.N.G. 99 trial.

PURPOSE EWS-ETS fusion genes are the driving force in Ewing's sarcoma pathogenesis. Because of the variable breakpoint locations in the involved genes, there is heterogeneity in fusion RNA and protein architecture. Since previous retrospective studies suggested prognostic differences among patients expressing different EWS-FLI1 fusion types, the impact of fusion RNA architecture on disease progression and relapse was studied prospectively within the Euro-E.W.I.N.G. 99 clinical trial. PATIENTS AND METHODS Among 1,957 patients who registered before January 1, 2007, 703 primary tumors were accessible for the molecular biology study. Fusion type was assessed by polymerase chain reaction on frozen (n = 578) or paraffin-embedded materials (n = 125). The primary end point was the time to disease progression or relapse. Results After exclusion of noninformative patients, 565 patients were entered into the prognostic factor analysis comparing type 1 (n = 296), type 2 (n = 133), nontype 1/nontype 2 EWS-FLI1 (n = 91) and EWS-ERG fusions (n = 45). Median follow-up time was 4.5 years. The distribution of sex, age, tumor volume, tumor site, disease extension, or histologic response did not differ between the four fusion type groups. We did not observe any significant prognostic value of the fusion type on the risk of progression or relapse. The only slight difference was that the risk of progression or relapse associated with nontype 1/nontype 2 EWS-FLI1 fusions was 1.38 (95% CI, 0.96 to 2.0) times higher than risk associated with other fusion types, but it was not significant (P = .10). CONCLUSION In contrast to retrospective studies, the prospective evaluation did not confirm a prognostic benefit for type 1 EWS-FLI1 fusions.

Epidemiology of leukaemia and lymphoma in children and young adults from the north of England, 1990-2002.

AIM: We aimed to describe and contrast the epidemiology of haematological malignancies among 0-14 and 15-24-year-olds in northern England from 1990 to 2002 and compare clinical trial entry by age group. PATIENTS AND METHODS: Incidence rates were examined by age, sex and period of diagnosis and differences were tested using Poisson regression. Differences and trends in survival were assessed using Cox regression. RESULTS: 1680 subjects were included comprising 948 leukaemias and 732 lymphomas. Incidence rates for acute lymphoblastic leukaemia were significantly higher for 0-14 compared to 15-24-year-olds, whilst Hodgkin lymphoma showed the reverse. No significant changes in incidence were observed. 60% of leukaemia patients aged 15-24 years entered trials compared to 92% of 0-14-year-olds. Survival rates were significantly lower and improved less markedly over time for 15-24 compared to 0-14-year-olds, particularly for leukaemia. CONCLUSIONS: Trial accrual rates need to be improved amongst 15-24-year-olds and a more structured follow-up approach adopted for this unique population.

High-dose rapid and standard induction chemotherapy for patients aged over 1 year with stage 4 neuroblastoma: a randomised trial.

BACKGROUND: The current standard treatment for patients with high-risk neuroblastoma includes initial induction chemotherapy with a 21-day interval between induction treatments. We aimed to assess whether an intensive chemotherapy protocol that had a 10-day interval between treatments would improve event-free survival (EFS) in patients aged 1 year or over with high-risk neuroblastoma. METHODS: Between Oct 30, 1990, and March 18, 1999, patients with stage 4 neuroblastoma who had not received previous chemotherapy were enrolled from 29 centres in Europe. Patients were randomly assigned to rapid treatment (cisplatin [C], vincristine [O], carboplatin [J], etoposide [E], and cyclophosphamide [C], known as COJEC) or standard treatment (vincristine [O], cisplatin [P], etoposide [E], and cyclophosphamide [C], ie, OPEC, alternated with vincristine [O], carboplatin [J], etoposide [E], and cyclophosphamide [C], ie, OJEC). Both regimens used the same total cumulative doses of each drug (except vincristine), but the dose intensity of the rapid regimen was 1.8-times higher than that of the standard regimen. The standard regimen was given every 21 days if patients showed haematological recovery, whereas the rapid regimen was given every 10 days irrespective of haematological recovery. Response to chemotherapy was assessed according to the conventional International Neuroblastoma Response Criteria (INRC). In responders, surgical excision of the primary tumour was attempted, followed by myeloablation (with 200 mg/m2 of melphalan) and haemopoietic stem-cell rescue. Primary endpoints were 3-year, 5-year, and 10-year EFS. Data were analysed by intention to treat. This trial is registered on the clinical trials site of the US National Cancer Institute website, number NCT00365755, and also as EU-20592 and CCLG-NB-1990-11. FINDINGS: 262 patients, of median age 2.95 years (range 1.03-20.97), were randomly assigned-132 patients to standard and 130 patients to rapid treatment. 111 patients in the standard group and 109 patients in the rapid group completed chemotherapy. Chemotherapy doses were recorded for 123 patients in the standard group and 126 patients in the rapid group. 97 of 123 (79%) patients in the standard group and 84 of 126 (67%) patients in the rapid group received at least 90% of the scheduled chemotherapy, and the relative dose intensity was 1.94 compared with the standard regimen. 3-year EFS was 24.2% for patients in the standard group and 31.0% for those in the rapid group (hazard ratio [HR] 0.86 [95% CI 0.66-1.14], p=0.30. 5-year EFS was 18.2% in the standard group and 30.2% in the rapid group, representing a difference of 12.0% (1.8 to 22.3), p=0.022. 10-year EFS was 18.2% in the standard group and 27.1% in the rapid group, representing a difference of 8.9% (-1.2 to 19.0), p=0.085. Myeloablation was given a median of 55 days earlier in patients assigned rapid treatment than those assigned standard treatment. Infective complications (numbers of patients with febrile neutropenia and septicaemia, and if given, time on antibiotic and antifungal treatment) and time in hospital were greater with rapid treatment. Occurrence of fungal infection was the same in both regimens. INTERPRETATION: Dose intensity can be increased with a rapid induction regimen in patients with high-risk neuroblastoma. There was no significant difference in OS between the rapid and standard regimens at 5 years and 10 years. However, an increasing difference in EFS after 3 years suggests that the efficacy of the rapid regimen is better than the standard regimen. A rapid induction regimen enables myeloablation to be given much earlier, which might contribute to a better outcome.

Ploidy and karyotype complexity are powerful prognostic indicators in the Ewing's sarcoma family of tumors: a study by the United Kingdom Cancer Cytogenetics and the Children's Cancer and Leukaemia Group.

Ewing's sarcoma family tumors (ESFT) are characterized by the presence of EWSR1-ETS fusion genes. Secondary chromosome changes are frequently described, although their clinical significance is not clear. In this study, we have collected and reviewed abnormal karyotypes from 88 patients with primary ESFT and a rearrangement of 22q12. Secondary changes were identified in 80% (70/88) of tumors at diagnosis. Multivariate analysis showed a worse overall and relapse free survival (RFS) for those with a complex karyotype (overall survival, P = 0.005; RFS, P = 0.04), independent of metastatic disease. Univariate survival analysis showed that a chromosome number above 50 or a complex karyotype was associated with a worse overall survival (>50 chromosomes, P = 0.05; complex karyotype, P = 0.04). There was no association between type of cytogenetic abnormality and the presence of metastatic disease at diagnosis. Univariate and multivariate survival analysis of a small subgroup with trisomy 20 indicated that trisomy 20 was associated with a worse overall and RFS. There was no difference in outcome associated with other recurrent trisomies (2, 5, 7, 8, or 12) or the common recurrent secondary structural rearrangements (deletions of 1p36, 9p12, 17p13, and 16q, and gain of 1q), although numbers were small. These data demonstrate the continued value of cytogenetics as a genome-wide screen in ESFT and illustrates the potential importance of secondary chromosome changes for stratification of patients for risk. Specifically, karyotype complexity appears to be a powerful predictor of prognosis, and the presence of trisomy 20 may be a marker of a more aggressive subset of this group.

Improvement in histologic response but not survival in osteosarcoma patients treated with intensified chemotherapy: a randomized phase III trial of the European Osteosarcoma Intergroup.

BACKGROUND: Previous randomized controlled trials that used the two-drug chemotherapy regimen of cisplatin and doxorubicin as the conventional arm showed no evidence of benefit from an increase in the number of agents or the length of treatment. It was then proposed that survival could be improved by increasing the planned dose intensity of cisplatin and doxorubicin. METHODS: Previously untreated patients with nonmetastatic, high-grade, central osteosarcoma of an extremity were randomly assigned to Regimen-C (conventional treatment with six 3-week cycles of cisplatin [100 mg/m2 by 24-hour infusion] and doxorubicin [25 mg/m2/day by 4-hour infusion for 3 days]) or to Regimen-DI (intensified treatment with identical total doses of cisplatin and doxorubicin, planned as six 2-week cycles supported by granulocyte colony stimulating factor (G-CSF). Surgery was scheduled for week 6 in both arms. Primary and secondary outcome measures were overall and progression-free survival, respectively. Intention-to-treat analyses were performed using standard survival analysis methods. Landmark analyses were performed in patients with known surgical details and centrally reviewed histologic response. All statistical tests were two-sided. RESULTS: Between May 1993 and September 2002, treatment was randomly allocated to 497 eligible patients. Six cycles of chemotherapy were completed by 78% of patients in Regimen-C and 80% of patients in Regimen-DI. The delivered preoperative median dose intensity of cisplatin was 86% in Regimen-C and 111% in Regimen-DI (as the percentage of that planned for the conventional regimen). Postoperative median dose intensity of cisplatin was 82% in Regimen-C and 110% in Regimen-DI (the corresponding figures for doxorubicin dose intensity were similar). Regimen-DI was associated with lower risks of severe leucopenia and neutropenia and higher risks of thrombocytopenia and mucositis. Good histologic response (>90% tumor necrosis) was observed in 36% of Regimen-C patients and 50% of Regimen-DI patients (P = .003, chi2 test). There was no evidence of a difference in overall survival (hazard ratio [HR] = 0.94, 95% CI = 0.71 to 1.24; P = .64) or progression-free survival (HR = 0.98, 95% CI = 0.77 to 1.24; P = .83). Landmark analyses showed similar results. CONCLUSIONS: Planned intensification of chemotherapy with cisplatin and doxorubicin increased received dose intensity and resulted in a statistically significant increase in favorable histologic response rate, but not in increased progression-free or overall survival. Our results call into question the use of histologic response as a surrogate outcome measure in trials of this disease.

Vascular endothelial growth factor: a therapeutic target for tumors of the Ewing's sarcoma family.

PURPOSE: We have reported previously that intratumoral microvessel density (MVD) is a significant prognostic indicator of event-free survival in the Ewing's sarcoma family of tumors (ESFT). Here, the angiogenic growth factor expression profile and its relationship with MVD has been investigated in ESFT. EXPERIMENTAL DESIGN AND RESULTS: Using ESFT model systems, the potential of these factors as therapeutic targets has been evaluated. A significant correlation (P = 0.02) was observed between vascular endothelial growth factor (VEGF) expression and MVD, consistent with the hypothesis that VEGF regulates the development of microvessels in ESFT. There was no correlation between MVD and any of the other growth factors studied. All six ESFT cell lines studied produced and secreted VEGF; five of six cell lines also secreted placental growth factor, one cell line (A673) at high levels. Tumor conditioned medium induced proliferation of human umbilical vein endothelial cells. Expression of VEGF receptors Flt-1 and Flk-1/KDR was heterogeneous across the cell lines. Both receptor tyrosine kinase inhibitors SU6668 (targets Flk-1/KDR, platelet-derived growth factor receptor-beta, and fibroblast growth factor receptor 1) and SU5416 (targets Flk-1/KDR) as well as anti-VEGF agents rhuMAb-VEGF (bevacizumab) and VEGF Trap delayed s.c. growth of ESFT in mice compared with untreated groups: SU6668 (100 mg/kg/d), SU5416 (25 mg/kg/d), rhuMAb-VEGF (10 mg/kg twice weekly), and VEGF Trap (2.5 or 25 mg/kg twice weekly). CONCLUSIONS: These data suggest that VEGF is the single most important regulator of angiogenesis in ESFT and may be exploited for therapeutic advantage.

Myogenin--a more specific target for RT-PCR detection of rhabdomyosarcoma than MyoD1.

BACKGROUND: MyoD1 and myogenin are differentially expressed in early myogenesis and have been identified in rhabdomyosarcoma (RMS). This study evaluates reverse transcriptase-polymerase chain reaction (RT-PCR) for MyoD1 and myogenin mRNA as diagnostic markers of RMS, and the potential application of this method for the detection of small volume disease in bone marrow (BM) and peripheral blood (PB). PROCEDURE: Expression of MyoD1 and myogenin mRNA was examined by RT-PCR in RMSs (9 alveolar RMS, 10 embryonal RMS, 1 pleomorphic RMS), and 21 other paediatric tumor samples (10 neuroblastoma, 10 Ewing sarcomas, and 1 Sarcoma (not otherwise specified) (S(NOS)). BM (n = 19) and PB (n = 22) samples from the same RMS study population were also examined for MyoD1 and myogenin mRNA expression. RESULTS: Positive expression of both markers was demonstrated in adult muscle, but not in normal PB. Myogenin mRNA was expressed in 16/18 and MyoD1 mRNA in 12/12 RMSs studied. Myogenin was not expressed in 10/10 neuroblastomas, but was present in 2/10 Ewing sarcomas. However, MyoD1 mRNA was detected in 10/10 Ewing sarcomas and 7/10 neuroblastomas. Myogenin mRNA was detected in two BM samples from children with histologically negative BM and in 1/22 PB samples. Detection of MyoD1 mRNA in BM and PB was compromised by the amplification of a similar sized, non-specific product. CONCLUSIONS: Myogenin mRNA is a more specific marker than MyoD1 for the diagnosis of RMS. Myogenin mRNA is potentially a useful target for the assessment of small volume disease in RMS.