Does debulking improve survival rate in advanced-stage retroperitoneal embryonal rhabdomyosarcoma?

Chemopreventive Effects and Antioxidant Capacity of Combined Leaf Extracts of Sesamum angustifolium (Oliv.) Engl. and Hibiscus articulatus on Rhabdomyosarcoma

Sesamum angustifolium (Oliv.) Engl. and Hibiscus articulatus contain compounds that have antimutagenic properties. The rise in rhabdomyosarcoma in paediatrics and prognosis of the disease in infants compared to adults calls for newer, less toxic alternatives in treatment of the disease. The aim of this study was to determine the anticancer activity and antioxidant capacity of combined leaf extracts of Sesamum angustifolium (Oliv.) Engl. and Hibiscus articulatus (SAHA), against rhabdomyosarcoma (RMS) using rhabdomyosarcoma (RD) cell line and mouse (L20B) cell line. Cytotoxicity, morphology, apoptosis induction, and antioxidant capacity assays were done. Of the four solvents used for extraction, the dichloromethane SAHA extract was the most cytotoxic with IC₅₀ of 106 μg/mL after doxorubicin, the reference anticancer drug with IC₅₀ of 0.8 μg/mL. The SAHA extracts had a stronger cytotoxicity effect on the cancerous RD cells than on normal L20B cells. Morphological assessment showed untreated cells maintained their normal striated appearance of muscle cells whereas cells treated with doxorubicin or SAHA extracts exhibited cell shrinkage, loss of surface adherence, reduced cell density along with cell debris, which is a characteristic of apoptosis. Normal L20B cells when treated with doxorubicin or SAHA extracts, maintained their cell shape, and remained adherent to the surface. The apoptotic enzyme caspase-3 was induced in a concentration dependent manner upon treatment of the RD cells with SAHA extracts or doxorubicin. Induction of caspase-3 was ten times less in treated L20B cells compared to the RD cells. Low induction of caspase-9 enzyme was observed in both treated RD and L20B cells. Treatment of both RD and L20B cells with SAHA extracts or doxorubicin resulted in increased activity of peroxidase and reduction of oxidative stress. Results of the study show that the SAHA extracts are potential sources of compounds that may serve as useful agents for treatment of rhabdomyosarcoma.

Rhabdomyosarcoma and Extraosseous Ewing Sarcoma

Rhabdomyosarcoma (RMS) is a malignant tumor that represents the most common form of pediatric soft tissue sarcoma. It arises from mesenchymal origin and forms part of the group of small round blue cell tumors of childhood. It has a constant annual incidence of 4.5 cases per 1,000,000 children. The known histological diagnosis of the two major subtypes (embryonal and alveolar) has been recently enhanced by tumor biological markers and molecular differentiation diagnostic tools that have improved not only the updated classification based on risk stratification, but also the treatment approach based on the clinical group. Ewing sarcoma (ES) is a round cell tumor, highly malignant and poorly differentiated that is currently the second most common malignant bone tumor in children. In rare instances, it develops from an extraskeletal origin, classified as extraosseous Ewing sarcoma (EES). We provide an updated, evidence-based and comprehensive review of the molecular diagnosis, clinical and diagnostic approach and a multidisciplinary medical and surgical management according to the latest standard of care for the treatment of pediatric RMS and EES.

Clinical outcomes of pediatric patients with newly diagnosed rhabdomyosarcoma treated by two consecutive protocols - A single institution report in Taiwan

BACKGROUND

Taiwan Pediatric Oncology Group (TPOG) initiated two consecutive protocols for treating pediatric patients with rhabdomyosarcoma since 1995. However, the results have not been analyzed and reported yet. The aim of this study is to investigate the treatment results of these two protocols in our hospital and to assess whether the results are comparable to other large-scaled studies.

METHODS

Treatment of pediatric patients with rhabdomyosarcoma according to TPOG protocols at National Taiwan University Hospital began in 1995. Between 1995 and 2006, patients were treated by TPOG RMS 95 protocol, which was based on IRS-III/IV. After 2007, patients were treated by TPOG RMS 2007 protocol which was adapted from IRS-V study. The clinical data of patients were obtained retrospectively by reviewing medical records. The date of the latest follow-up was December 31, 2016.

RESULTS

Thirty-seven patients were enrolled in this study. The 5-year overall survival (OS) and event-free survival rates of them were 54.7 ± 8.8% and 48.5 ± 8.6%, respectively. The 5-year OS rates for patients treated by TPOG RMS 95 and TPOG RMS 2007 protocols were 55.0 ± 11.1% and 55.9 ± 14.0%, respectively. Age at diagnosis of less than ten years old and receiving operation with gross total or subtotal tumor resection were identified as independent prognostic factors that predicted better outcomes in the multivariate analysis.

CONCLUSION

The clinical outcomes of pediatric patients with rhabdomyosarcoma in Taiwan improved dramatically after incorporating two consecutive protocols from TPOG. In addition, the treatment results of these two protocols were comparable to large-scale studies of other countries.

What is new in rhabdomyosarcoma management in children?

Optimal management of rhabdomyosarcoma requires establishing the correct pathologic diagnosis, histologic sub-type, primary site, extent of disease (Stage), and extent of resection (Group). Based on these features, cooperative groups in North America and Europe have defined risk-adapted treatments that include surgery, chemotherapy, and usually radiotherapy. This article focuses on recent findings that can impact or have already impacted rhabdomyosarcoma treatment guidelines and highlights controversies that should be addressed in order to improve outcome for children with rhabdomyosarcoma. Rhabdomyosarcoma is currently sub-classified in children based on histology into the favorable embryonal/botryoid/spindle cell types and the unfavorable alveolar form. Risk group assignment depends in part on histologic sub-type. Alveolar rhabdomyosarcoma is sometimes associated with chromosomal translocations, which impact clinical behavior. An important ongoing debate is whether molecular diagnostic tools to identify chromosomal translocations and/or define gene expression profiles should be used to sub-classify rhabdomyosarcoma rather than histology. Clinical trials continue to evaluate retrospective as well as prospective cohorts in order to carefully determine the impact of histology versus biologic features on outcome in the context of specific therapeutic regimens. Most rhabdomyosarcoma recurrences involve the primary site or adjacent region. Cooperative groups continue to investigate new approaches to local control in order to reduce local recurrences and sequelae associated with local therapy. Delaying primary resection until after chemotherapy has started appears to increase the number of tumors that can be completely resected with acceptable morbidity in some primary sites. Radiation dose reductions following delayed primary resection have been investigated. Although outcomes appear similar to the conventional approach of full-dose radiotherapy without delayed primary resection, long-term effects of the two approaches have not been rigorously compared. Early evidence suggests that newer methods of delivering radiotherapy, including intensity-modulated radiotherapy (IMRT), proton beam radiotherapy, and brachytherapy maintain efficacy but may reduce long-term sequelae compared with 3-dimensional conformal radiotherapy. Chemotherapy regimens defined by the cooperative groups vary by risk group. The most commonly used regimens include vincristine and dactinomycin in combination with an alkylating agent, either cyclophosphamide or ifosfamide. In order to improve outcomes, recent clinical trials have introduced new chemotherapeutic agents (e.g. topotecan, carboplatin, or epirubicin) into the treatment regimens. However, outcomes have not been significantly impacted. Novel chemotherapy administration schedules have been tested in patients with metastatic rhabdomyosarcoma, including interval compressed dosing or maintenance therapy, and may be promising. Molecularly targeted agents are currently under investigation in combination with chemotherapy for patients with recurrent or metastatic rhabdomyosarcoma. It is hoped that these novel agents will benefit all patients with rhabdomyosarcoma in the future.

Radiotherapy for rhabdomyosarcoma: indications and outcome

Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood. Improvements in the clinical outcomes of rhabdomyosarcoma have been secondary to the intensification and refinement of treatment investigated by the Intergroup Rhabdomyosarcoma Study Group. Advances in diagnostic imaging techniques have led to improvements in staging and contribute to precision in radiation field design. Radiation treatment has been integrated into the primary treatment of most patients with rhabdomyosarcoma. Each treatment site has special considerations with regards to prognosis, outcomes and potential morbidities that affect the choice of local therapy. Advanced radiotherapy techniques using conformal treatment with intensity-modulated radiotherapy and proton therapy are particularly advantageous for the treatment of sites close to critical structures, such as the head and neck and genitourinary system. Active investigation is underway to develop strategies to reduce the radiation dose and volume in an effort to minimise late toxicity and improve the therapeutic ratio.

Long-term survival results of pediatric rhabdomyosarcoma patients: a single-center experience from Turkey

The characteristics and clinical outcomes of 409 children with rhabdomyosarcoma, treated in a single center between 1972 and 2003, were evaluated to identify those characteristics that may have improved the outcome. Retrospective analysis was performed on 409 children for variables such as age, sex, primary tumor site, TNM (Tumor, Node, Metastasis) stage, Intergroup Rhabdomyosarcoma Studies (IRS) clinical group, histological subtypes, treatment. The mean age was 5.4 years and the male/female ratio was 1.6/1.0. Most of the patients were at stage III and the most common site of metastases was the lung. The median time of follow-up was 114 months. The 10-year event-free survival and overall survival rates were 27% and 33%, respectively. All parameters apart from sex and histological subtypes were found to be correlated with clinical outcome. Orbital and genitourinary system tumors (bladder-prostate tumors excluded), patients >1 year of age, TNM stage I and II tumors, IRS clinical group I and II tumors, grossly resectable tumors, and treatment with chemotherapy protocols containing anthracyclines correlated with better prognoses. In multivariate analyses, tumor invasion to surrounding tissue, regional lymph node involvement, and debulking surgery were found to be negatively correlated with prognosis. In children with rhabdomyosarcoma, survival rates can be improved owing to factors such as advancement in diagnostic and therapeutic techniques, improved supportive care, and a multidisciplinary approach.

Update on rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a malignant childhood tumor of mesenchymal origin that currently has a greater than 70% overall 5-year survival. Multimodality treatment is determined by risk stratification according to pretreatment stage, postoperative group, histology, and site of the primary tumor. Pretreatment staging is dependent on primary tumor site, size, regional lymph node status, and presence of metastases. Unique to RMS is the concept of postoperative clinical grouping that assesses the completeness of disease resection and takes into account lymph node evaluation. At all tumor sites, the clinical grouping, and therefore completeness of resection, is an independent predictor of outcome. Overall, the prognosis for RMS is dependent on primary tumor site, patient age, completeness of resection, extent of disease, including the presence and number of metastatic sites and histology and biology of the tumor cells. Therefore, the surgeon plays a vital role in RMS by contributing to risk stratification for treatment, local control of the primary tumor, and outcome. The current state-of-the-art treatment is determined by treatment protocols developed by the Soft Tissue Sarcoma Committee of the children's Oncology Group.

Local therapy for rhabdomyosarcoma of the hands and feet: is amputation necessary? A report from the Children's Oncology Group

PURPOSE

To evaluate the outcome of children with rhabdomyosarcoma (RMS) of the hand or foot treated with surgery and/or local radiotherapy (RT).

METHODS AND MATERIALS

Forty-eight patients with nonmetastatic RMS of the hand or foot were enrolled on Intergroup Rhabdomyosarcoma Study III, IV-Pilot, and IV. Patients received multiagent chemotherapy with surgery and/or RT. Twenty-four patients (50%) underwent surgery without local RT, of whom 4 had complete resection and 20 had an amputation. The remaining 24 patients (50%) underwent local RT, of whom 2 required RT for microscopic residual disease after prior amputation. Median follow-up for surviving patients was 9.7 years.

RESULTS

Actuarial 10-year local control was 100%; 10-year event-free survival and overall survival rates were 62% and 63%, respectively. Poor prognostic factors for recurrence included gross residual (Group III) disease and nodal involvement (p = 0.01 and 0.05, respectively). More patients in the RT group had alveolar histology, Group III disease, and nodal involvement, as compared with the surgery group. There was no difference in 10-year event-free survival (57% vs. 66%) or overall survival (63% vs. 63%) between patients who underwent surgery or local RT. Among relapsing patients, there were no long-term survivors. No secondary malignancies have been observed.

CONCLUSIONS

Despite having high-risk features, patients treated with local RT achieved excellent local control. Complete surgical resection without amputation is difficult to achieve in the hand or foot. Therefore, we recommend either definitive RT or surgical resection that maintains form and function as primary local therapy rather than amputation in patients with hand or foot RMS.

Biopsy or debulking surgery as initial surgery for locally advanced rhabdomyosarcomas in children?: the experience of the Italian Cooperative Group studies

BACKGROUND

The purpose of the current study was to analyze the influence of the initial surgical approach (biopsy vs resection with macroscopic residual tumors) on the outcome of patients with localized Intergroup Rhabdomyosarcoma Study (IRS) Group III rhabdomyosarcoma (RMS) enrolled in the Italian studies between 1979 and 2003.

METHODS

Among the 394 patients evaluated, 323 underwent biopsy, as recommended by the protocols, and 71 patients underwent surgical resection with macroscopic residual tumors (debulking operation [DO]), although this procedure was discouraged. All these patients were classified at the same risk group and received the same treatment. The different characteristics (patient age, tumor site, T classification and size, histology) and outcome in the 2 groups were considered.

RESULTS

The estimated 5-year overall survival (OS) rates were 68.4% and 72.6%, respectively, after biopsy and DO (P=.38), and the rates of progression-free survival (PFS) were 56.5% and 61.7%, respectively, after biopsy and DO (P=.41). The outcome did not differ significantly when considering other variables such as tumor site, size, and histology. Age>10 years appeared to have little benefit in patients with DO; the OS was 62% after biopsy and 83.1% after DO (P=.06); the PFS was 49.7% and 72.8%, respectively after biopsy and DO (P=.04). No surgical complications due to the 2 procedures were reported, but in 2 cases the initial DO resulted in a mutilation.

CONCLUSIONS

No significant advantages of DO versus biopsy were detected with regard to patient outcome. Biopsy, which is less aggressive, appears to be thebest option for patients with IRS Group III RMS.

Pediatric surgical oncology: management of rhabdomyosarcoma

A malignant tumor of striated muscle origin, Rhabdomyosarcoma (RMS) is a childhood tumor that has benefited from 30 years of multimodality therapeutic trials culminating in a greater than 70% overall current 5-year survival. Prognosis for RMS is dependent on anatomic primary tumor site, age, completeness of resection, presence and number of metastatic sites, histology and biology of the tumor cells. Multimodality treatment is based on risk stratification according to pretreatment stage, postoperative group, histology and site. Therefore, pretreatment staging is vital for assessment and is dependent on primary tumor site, size, regional lymph node status, and presence of metastases. Unique to RMS is the concept of postoperative clinical grouping that assesses the completeness of disease resection and takes into account lymph node evaluation both at the regional and metastatic basins. At all sites, if operative resection of all disease is accomplished, including microscopic disease, survival is improved. Therefore, the surgeon plays a vital role in determining risk stratification for treatment and local control of the primary tumor for RMS.

Retroperitoneal sarcomas in children: outcomes from an institution

BACKGROUND

Retroperitoneal sarcomas are uncommon in children and tend to present as large tumors with advanced locoregional involvement of abdominopelvic structures. Surgical control of these tumors remains to be a management challenge. We reviewed our institutional experience with retroperitoneal sarcomas in children.

MATERIALS AND METHODS

In a retrospective review of charts dating between 1975 and 2005, we identified patients younger than 18 years who were diagnosed with a histologically confirmed retroperitoneal sarcoma. Patients were followed prospectively through clinic visits and mail correspondence. Standard statistical methods were used for comparative, risk, and survival analyses.

RESULTS

Twenty-one children with a mean age at presentation of 9 +/- 1 years were identified. There were more boys than girls (male/female ratio = 1.6). The most common presentations were abdominal mass/distention (76%) and pain (62%). The mean tumor size was 14.2 +/- 1.4 cm, with locoregional involvement in 62% of the patients. The common histologic types were rhabdomyosarcoma (33%) and fibrosarcoma (33%). Seventy-six percent of the patients underwent primary or secondary resection, 71% received neoadjuvant and/or adjuvant chemotherapy therapy, and 38% received radiation therapy. Complete resection was achieved in 48% of the patients, including 3 who required inferior vena cava resection and reconstruction. The 5-year disease-specific survival rates for patients who underwent complete resection and those who underwent incomplete resection were 90% and 36% (P = .018), respectively. For all patients, the mean survival time was 103 +/- 16 months and the 5-year disease-specific survival rate was 62%. Survival was significantly better for patients with low-grade sarcomas than for those with high-grade sarcomas (90% vs 36%, P = .008). Among those who underwent an initial complete resection, 50% had a recurrence at a mean time of 88 +/- 52 months (range = 3-261 months). The 30-day postoperative mortality and morbidity rates were 0% and 24%, respectively; in addition, 14% of the patients experienced long-term complications.

CONCLUSIONS

Resection of retroperitoneal sarcomas can be performed safely with minimal morbidity and mortality. Complete resection and low histologic grade are associated with significantly better disease-specific survival.

Role of surgery in the management of soft tissue tumors

Pediatric soft tissue sarcomas (STSs), of which rhabdomyosarcoma is the most common, constitute approximately 5-6% of all cancers in children. Biopsy, being incisional or rarely excisional, is an essential primary diagnostic step, while in some cases it may be followed by primary re-excision to establish a correct diagnosis in which molecular analysis can be helpful. Most European STS treatment groups favor preoperative chemotherapy, sometimes combined with preoperative irradiation. Local therapy is essential, in which surgery remains an important adjunct. However, it has to be applied in a multidisciplinary, combined fashion in close cooperation with oncologists, pathologists and radiotherapeutists. Current 5-year survival in rhabdomyosarcoma reaches 60-70% in nonmetastatic cases and remains below 20% in metastatic situations. Outcome in pediatric nonrhabdomyosarcoma STS is similar.

Results of treatment of fifty-six patients with localized retroperitoneal and pelvic rhabdomyosarcoma: a report from The Intergroup Rhabdomyosarcoma Study-IV, 1991-1997

BACKGROUND

We reviewed 56 IRS-IV patients with localized rhabdomyosarcoma [RMS] of the retroperitoneum/pelvis to assess outcome and prognostic factors, including the value of initially excising >or=50% of the tumor (debulking) before chemotherapy.

METHODS

Patients had embryonal RMS [N=38], alveolar RMS [N = 7], RMS not otherwise specified [NOS, N = 7], or undifferentiated sarcoma [N = 4]. Fifteen patients were debulked; 41 patients were biopsied. All received VAC; most received radiotherapy.

RESULTS

Estimated 5-year failure-free survival [FFS] and overall survival rates were 70 and 75%, respectively. FFS rates were better for patients <10 years old and those with embryonal RMS compared to alveolar RMS/undifferentiated sarcoma. After adjusting for age and histological differences, FFS was better for patients whose tumor was debulked prior to beginning therapy [P = 0.02].

CONCLUSIONS

These results are superior to those of previous protocols for patients with RMS of the retroperitoneum/pelvis. Initial excision of >or=50% of the tumor may be associated with increased FFS.

Efficacy of ifosfamide and doxorubicin given as a phase II "window" in children with newly diagnosed metastatic rhabdomyosarcoma: a report from the Intergroup Rhabdomyosarcoma Study Group

BACKGROUND

The cure rate for children/adolescents with localized rhabdomyosarcoma (RMS) has tripled over the past 25 years, but patients with metastatic disease at presentation have not benefited similarly, and urgently need new therapy. We evaluated a new drug pair, ifosfamide + doxorubicin, for such patients.

PROCEDURE

We estimated the complete and partial response rates (i.e., CR and PR) of 152 previously untreated children/adolescents with metastatic RMS entered on the IRS-IV pilot from July 1988 to October 1991 who received an "up-front window" of ifosfamide (1.8 gm/m(2)/day for 5 days) and doxorubicin (30 mg/m(2)/day for 2 days) given every 3 weeks for 12 weeks. This was followed by combination chemotherapy with vincristine, actinomycin D, and cyclophosphamide (VAC), given every 3 weeks for an additional 36 weeks.

RESULTS

Of 115 patients evaluable for early response at 12 weeks, 28 (20%) had CR and 66 (43%) had PR. The ultimate CR rate was 52%. Overall, about one-third of patients survived. Prognostic factor analysis revealed that patients < 10 years old (P < 0.001), those with embryonal tumors (P = 0.002), or a GU primary site (P = 0.010), and those who lacked nodal disease (P = 0.041), and those who lacked bone or bone marrow metastasis (P < 0.001) fared better than did others.

CONCLUSIONS

The 63% CR + PR rate achieved at 12 weeks and overall 5-year FFS seen with this drug pair is similar to that achieved with previously evaluated drug combinations. We conclude that ifosfamide/doxorubicin is highly active in advanced RMS, and should be considered for inclusion in frontline therapy for children with intermediate or high-risk RMS.

Issues in the local control of rhabdomyosarcoma

BACKGROUND

Rhabdomyosarcoma (RMS) is a heterogeneous disease consisting of several different histologies arising from a variety of anatomic sites. Approximately half of the children who die of this tumor have failure at the primary site of involvement, making local control an important component of therapy.

PROCEDURE

Published literature and newly analyzed data from the Intergroup Rhabdomyosarcoma Study Group (IRSG) regarding local control of RMS were reviewed. Information regarding the role of various local control modalities for different primary disease sites is presented along with new directions for clinical research.

RESULTS

Local control rates for RMS average 80% for group III tumors, with large variations seen for different anatomic sites. Important gains in functional outcome for certain sites such as gynecologic system and bladder/prostate have been achieved by optimizing the use of the various treatment modalities. Local control at other sites such as the chest and extremities remains a problem.

CONCLUSIONS

Advances in surgical and radiotherapy techniques coupled with multiagent chemotherapy are providing improved local control with decreasing morbidity. Optimal outcome is dependent on close collaboration between surgical, radiotherapy, and pediatric oncology specialists.

Rhabdomyosarcoma and soft tissue sarcoma in childhood

The past year has seen a greater understanding of the means by which the alveolar rhabdomyosarcoma gene fusions (PAX-FKHR) lead to the malignant phenotype. The treatment of the primary tumor in rhabdomyosarcoma has been reexamined, with the roles of surgery and radiation expanding in American studies and decreasing in European ones. "Megatherapy" approaches with stem cell or bone marrow autologous transplants still have not found a role in the treatment of metastatic rhabdomyosarcoma. Our understanding of the natural history of nonrhabdo soft tissue sarcomas in children has increased, and molecular diagnosis is becoming established. The role of chemotherapy in treatment remains controversial.

Pediatric genitourinary tumors

Advances in our knowledge of pediatric genitourinary tumors are being made at both the basic science and clinical levels. The molecular mechanisms underlying these pediatric malignancies are being uncovered and will aid in uncovering novel treatments. Because of the high success rate in treating these tumors, treatment options are being modified to decrease both short- and long-term morbidity, while maintaining the improved survival.

Risk-based management: current concepts of treating malignant solid tumors of childhood

BACKGROUND

Improved survival with pediatric malignancies has been positively influenced by multidisciplinary cooperative studies using surgery, chemotherapy, and radiation therapy, but one-third of all children with cancer succumb to their condition. The identification of biologic and genetic characteristics as risk factors for the various tumors has led to changes in treatment using risk-based management as the template for care.

STUDY DESIGN

The purpose of this report is fourfold: (1) to review survival data concerning three solid malignant tumors of childhood (Wilms' tumor, rhabdomyosarcoma, and neuroblastoma), (2) to describe important prognostic genetic and biologic risk factors for each tumor, (3) to update changes in staging criteria, and (4) to familiarize the reader with the concept of risk-based management, which individualizes treatment in an attempt to maximize survival and minimize longterm morbidity.

RESULTS

The overall survival rates for Wilms' tumor, rhabdomyosarcoma, and neuroblastoma are currently 90%, 70%, and 40%, respectively. Most patients with Wilms' tumor have favorable histology and survive after nephrectomy and chemotherapy, but 10% have poor prognostic variables, including unfavorable (anaplastic) histology, chromosomal loss on 1p and 16q, and diploidy. Instances of lung or liver metastases, major tumor spillage during resection, remote lymph node involvement, and bilateral tumors have worse outcomes. Rhabdomyosarcoma is associated with chromosomal translocation of t(2:13) in alveolar types, the p53 tumor suppressor gene, and 11p15. Survival is dependent on the tumor site and pretreatment clinical group. Orbit, paratesticular, vulvar, and vaginal tumors have a good prognosis, but other genitourinary tumors, extremity and trunk lesions, and parameningeal head and neck tumors have a worse prognosis. Survival rates by clinical group are stage I, 93%; II, 81%; III, 73%; and IV, 30%. Resectability, lymph node involvement, DNA ploidy, and pretreatment TNM staging affect outcomes. Neuroblastoma is an embryonal tumor with bizarre behavior and can regress, mature, or rapidly progress. Most patients have advanced disease at diagnosis. Neuroblastoma is associated with loss of heterozygosity on chromosome 1p36 and occasionally deletions on 14q and 17q. Survival is affected by age and stage (at less than 1 year, stages I [95% to 100%], II [85% to 90%], and IV-S [more than 80%] do better) and other risk factors. Patients with advanced disease (older than 1 year, stage III [70%], and stage IV [12%]) often have amplification of the N-myc oncogene, diploid tumors, 1p36 deletion, and unfavorable histology and fare worse.

CONCLUSIONS

On the basis of these data, children with solid tumors are currently categorized into low-, intermediate-, and high-risk groups. Newer protocols individualize treatment using risk factors as predictors of outcomes. Risk-based management allows the clinician to weigh the risks and benefits of treatment for each patient to maximize survival, minimize longterm morbidity, and improve the quality of life.