Early history of pathology studies by the Intergroup Rhabdomyosarcoma Study Group.

This review chronicles the series of publications that were the result of the willingness of pathologists and clinicians in the United States to share their pathologic materials and clinical data on patients who were placed on treatment protocols for rhabdomyosarcoma and related tumors over an extended period of time. The availability of this database enabled pathologists and clinicians to study a tumor type that is rare in individual institutions, but occurs in large enough numbers to produce valid conclusions not otherwise possible. Furthermore, young investigators were challenged by this opportunity and were able to spend the necessary time to make new observations that, in retrospect, helped direct protocol designs that produced significant improvement in patient survival. The key factor in this process is the surrender of individual scientific prerogatives to a small number of investigators. It is also important to recognize that the pathologist component of these series of contributions is only a part of the entire effort. It takes an organization of gifted, dedicated experts in many disciplines working together. The investigators who served on the Intergroup Rhabdomyosarcoma Group over a 25-year period eminently fulfilled this.

Intergroup Rhabdomyosarcoma Study: update for pathologists.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood, and 75% of such cases in the United States are reviewed at the Pathology Center for the Intergroup Rhabdomyosarcoma Study Group (IRSG). The first four generations of IRSG therapeutic trials (IRS I-IV) and supportive pathologic studies have generated a new International Classification of Rhabdomyosarcoma (ICR) that offers new morphologic concepts to the practicing pathologist. The objective of this report is to clearly define emerging histopathologic categories of RMS as defined by the ICR, and to emphasize correlative immunohistochemical or molecular studies. Emerging ICR variants of RMS place the patient in widely divergent prognostic categories (superior, botryoid or spindle cell variants; poor, solid alveolar or diffusely anaplastic variants). The cardinal histopathologic features of the ICR combined with results of studies of fusion genes seen with t(1;13) and t(2;13) will help delineate therapeutic subgroups of RMS for the fifth generation (IRS V) of IRSG studies. Consequently, it is imperative for the practicing pathologist to be familiar with the practical workup and diagnosis of RMS in childhood.

Undifferentiated sarcomas of children: pathology and clinical behavior--an Intergroup Rhabdomyosarcoma study.

Undifferentiated soft tissue sarcoma (UND-STS) is the most poorly defined tumor eligible for intergroup Rhabdomyosarcoma Studies (IRS). Recent IRS UND-STS experience was reviewed to assess the histologic characteristics and clinical behavior of undifferentiated sarcomas. Of the 1,527 patients entered on IRS-III and IRS pilot-IV, 96 had tumors classified by the IRS Pathology Committee as UND-STS. Of these, 52 had adequate histologic material for this study. After application of immunohistochemistry, 18 tumors were reclassified, mostly as embryonal rhabdomyosarcomas (RMS), primitive neuroectodermal tumors, and intraabdominal desmoplastic small found cell tumors. The remaining 34 UND-STS had a diffuse hypercellular histologic pattern made up of sheets of medium-sized cells. The tumor cells had a minimal to moderate amount of cytoplasm and a variable nuclear morphology, predominately vesicular with finely granular chromatin. Except for reactivity with antibodies against vimentin, most tumors had a negative immunohistochemical profile. The 5 year Kaplan-Meier survival estimate for patients with non-metastatic disease was 72%, a significant improvement when contrasted with patients diagnosed to have UND-STS in IRS-I and IRS-II.

Primary and metastatic rhabdomyosarcoma in the breast: neoplasms of adolescent females, a report from the Intergroup Rhabdomyosarcoma Study.

UNLABELLED: The occurrence of rhabdomyosarcoma (RMS) primary in or metastatic to breast has been regarded as an uncommon event, associated with an unfavorable outcome. Records of 26 patients with diagnoses of breast RMS, either primary or secondary, entered in the Intergroup Rhabdomyosarcoma Study (IRS) (1972-1992) were reviewed and compared with data regarding 47 similar patients in published reports. Of the 26 IRS cases, the histologic subtype was alveolar in 24, embryonal in 1, and not determined in 1. All were female with ages ranging from 11.5 to 20.2 years (median, 15.2 years; mode, 14-16 years). This compact age distribution of both primary (n = 7) and metastatic (n = 19) breast RMS was seen in previously reported series. Among the 19 cases of RMS with initial dissemination to breast, primary tumor sites, were extremity (n = 8), nasopharynx/paranasal sinuses (n = 7), and trunk (n = 4). IRS treatment was risk-based according to site and extent of disease. Four of 7 patients with primary RMS remain disease free 2.9 to 7 years post diagnosis. Among 19 patients with RMS initially metastatic to breast, including 7 in IRS clinical group IV at original diagnosis, three are disease free at 7.6, 15.7 and 17.0 years. CONCLUSIONS: primary or metastatic RMS in breast is almost confined to adolescent females having tumors with alveolar histology. Approximately one-half of the patients with primary breast disease and 15% of those with metastatic breast disease as an initial recurrence are long-term survivors.

Orbital rhabdomyosarcomas and related tumors in childhood: relationship of morphology to prognosis--an Intergroup Rhabdomyosarcoma study.

Children and adolescents who develop rhabdomyosarcoma (RMS) and related sarcomas in the orbit and treated on Intergroup Rhabdomyosarcoma protocols have had an extremely high cure rate. This study evaluates the possible relationship between their tumor morphologic subtypes and this high cure rate. The histology of tumors was re-reviewed from 229 of the 264 patients with tumors of the orbit, conjunctiva, and eyelids treated on Intergroup Rhabdomyosarcoma Studies (IRS I, II, III, and IV pilot protocols, and followed through July, 1992. Immunohistochemistry was applied in selected cases. Clinical correlations were done on all 264 cases including both the re-reviewed cases and those reviewed only by the IRS Pathology committee. The 5-year survival rate of 24 children with alveolar RMS was 74% (p < .001). All five infants diagnosed to have an alveolar RMS died before the age of one. Two hundred and twenty-one patients (84%) had embryonal RMS. About three-fourths of the re-reviewed embryonal RMS tumors showed only minimal rhabdomyoblastic differentiation. Thirty-one had a spindle cell RMS, two were anaplastic variants. The 5-year survival rate for patients with embryonal RMS subtypes combined was 94%, and 97% for the 144 patients with poorly differentiated embryonal RMS. In contrast, 90 of 432 IRS II patients treated for poorly differentiated embryonal RMS located in extraocular sites had a 66% survival estimate.

Ewing's sarcoma of soft tissues in childhood: a report from the Intergroup Rhabdomyosarcoma Study, 1972 to 1991.

PURPOSE: One hundred thirty of 2,792 patients (5%) registered on three Intergroup Rhabdomyosarcoma Study clinical trials (IRS-I, -II, and -III) from 1972 to 1991 had an extraosseous Ewing's sarcoma (EOE). We report here the results of multimodality therapy for this tumor. PATIENTS AND METHODS: The 130 patients were less than 21 years of age; 70 (54%) were males. Primary tumor sites were on the trunk in 41 patients, an extremity in 34, the head/neck in 23, the retroperitoneum/pelvis in 21, and other sites in 11. One hundred fourteen patients had no metastases at diagnosis. In 21 patients, the tumor was completely resected; in 30, the localized or regional tumor was grossly resected, and in 63 patients, grossly visible sarcoma was left behind. Sixteen patients (12%) had distant metastases at diagnosis. All patients were given multiagent chemotherapy and most received irradiation (XRT); none were treated with bone marrow transplantation. RESULTS: One hundred seven patients (82%) achieved a complete response. At 10 years, 62%, 61%, and 77% of the patients were alive after treatment on IRS-I, IRS-II, or IRS-III therapeutic protocols, respectively, similar to figures obtained in all IRS patients. At last follow-up evaluation, 42 patients had died of progressive tumor and one of infection. Survival at 10 years was most likely for patients with tumor that arose in the head and neck, extremities, and trunk, and for those who underwent grossly complete tumor removal before initiation of chemotherapy. For patients with localized, gross residual tumor, adding doxorubicin (DOX) to the combination of vincristine, dactinomycin, cyclophosphamide (VAC), and XRT did not significantly improve survival in 39 patients (62% alive at 10 years) compared with that of 24 patients treated with VAC and XRT without DOX (65% alive at 10 years, P = .93). CONCLUSION: This series indicated that EOE in children is similar to rhabdomyosarcoma (RMS) in its response to multimodal treatment. No benefit was apparent from the addition of DOX to VAC chemotherapy in patients with gross residual EOE.

Preservation of the bladder in patients with rhabdomyosarcoma.

PURPOSE: To review the pathologic findings from children with gross residual rhabdomyosarcoma (RMS) of the bladder and compare the treatment outcome of those who underwent cystectomy with those who did not. PATIENTS AND METHODS: Primary and follow-up records and pathology specimens for 28 patients with gross residual disease entered onto the intergroup Rhabdomyosarcoma Study (IRS) III were reviewed. These patients were assigned to receive 20 weeks of multiagent induction chemotherapy and 4 weeks of radiotherapy. Future therapy decisions were based on clinical and histologic evaluation at 20 weeks. RESULTS: All patients had a clinical and histologic response. Thirteen patients underwent cystectomy at intervals that ranged from 1.5 to 38 months after the start of therapy. All but one patient are alive and well without recurrence. Reasons for cystectomy included presumed evidence of tumor growth from imaging studies, findings at cystoscopy, or histologic interpretation of biopsies. In 12 of 14 specimens from 15 patients who retained their bladder, no tumor cells were seen at first or second evaluation. In cystectomy specimens, tumor cellularity was markedly reduced and all tumor cells were in varying degrees of cellular maturation. Review of primary tumor specimens showed a greater degree of cellular maturation in patients with retained bladders than in those who underwent cystectomy. CONCLUSION: Bladder RMS is responsive to chemotherapy and radiotherapy. Twelve of 26 patients showed complete loss of tumor cells after induction therapy. Cystectomy specimens showed diminished tumor cells with varying degrees of cellular maturation. It is hypothesized that these tumors may have shown further maturation and ultimate loss of matured cells with continuing therapy.

Pseudosarcomatous myofibroblastic tumor of the urinary bladder in children: a study of 11 cases with review of the literature. An Intergroup Rhabdomyosarcoma Study.

Pseudosarcomatous myofibroblastic tumor (PMT) is the result of reactive proliferation of myofibroblasts. In children, PMT of the urinary bladder can be mistaken for embryonal rhabdomyosarcoma clinically, radiologically, and by light microscopy. We are reporting the clinical, histological, and immunohistological features of 11 patients with childhood PMT of urinary bladder that were diagnosed initially as a sarcoma, usually rhabdomyosarcoma. The morphologic spectrum of PMT is broad, with mixtures of myxoid, leiomyomatous, and sclerosing matrix patterns, the myxoid type being the most common. The proliferating cells consist of three forms of myofibroblastic cells: long spindle cells (type I), intermediate spindle cells (type II), and ganglion-like cells (type III), together with various types of inflammatory cells. The immunohistologic profile of the proliferating cells was characterized by positive reactions to vimentin, muscle-specific actin, alpha-smooth-muscle actin, polyclonal desmin, and keratin. Ultrastructural studies showed myofibroblastic differentiation of the tumor cells. No patients have had metastases or local recurrence. Histologic, immunohistochemical, and clinical data from 71 cases of PMT, including the 11 cases in this report, confirm the benign behavior of these lesions. The etiology of these lesions is unclear, including the absence of surgical or other trauma in all of the children.

Cyclophosphamide dose escalation in combination with vincristine and actinomycin-D (VAC) in gross residual sarcoma. A pilot study without hematopoietic growth factor support evaluating toxicity and response.

PURPOSE: The Intergroup Rhabdomyosarcoma Study (IRS) initiated an escalating-dose cyclophosphamide (Cyc) pilot without hematopoietic growth factor (HGF) support in combination with vincristine (Vcr) and actinomycin-D (Amd), known as VAC, to establish a Cyc dose with myelotoxicity comparable to an ifosfamide (Ifos), Vcr, and Amd combination regimen (VAI). A Cyc dose equivalent to Ifos was to be determined when comparable myelotoxicity was achieved. PATIENTS AND METHODS: Patients with either rhabdomyosarcoma or undifferentiated soft-tissue sarcoma and gross residual (clinical group III) disease were eligible for the VAC pilot. Feasibility and toxicity were evaluated in the VAC pilot at each Cyc level before escalating the dose. Starting at CYC 1.2 g/m2 dose escalation was planned at increments of 20-25% in cohorts of 8-10 patients until myelotoxicity at a severe or worse grade was seen in > 90% of the patients. RESULTS: One hundred nineteen eligible patients were evaluated for toxicity and response at four Cyc levels: 1.2, 1.5, 1.8, and 2.2 g/m2. Eight of 87 (9%) evaluable at 2.2 g/m2 had a toxic death. Six of these were attributable to myelotoxicity. Patients age 1-3 years were most vulnerable. The overall complete response (CR) rate of 68% was poorly predicted by the weeks 8 and 20 CR rates of 20 and 40%, respectively. During the first year and overall, myelotoxicity at 2.2 g/m2'1 with VAC was comparable to Ifos 1.8 g/m2'5. Cyc was relatively more myelotoxic than Ifos in the second year of the VAC pilot. Based on actual amount of drug given, a standardized Ifos dose of 9.0 g/m2 was equivalent to 2.1 g/m2 of Cyc, giving an Ifos/Cyc ratio of 4.3. CONCLUSION: Myelotoxicity using 2.2 g Cyc/m2 in a single intravenous infusion was dose limiting in this VAC pilot without HGF. In the first year and overall, myelotoxicity is comparable to that with VAI using Ifos at 9.0 g/m2. An ongoing IRS-IV randomized trial of VAC and VAI should provide a comparison of the efficacy of Ifos and Cyc in children and adolescents with embryonal or alveolar rhabdomyosarcoma and undifferentiated soft-tissue sarcomas.

Classification of rhabdomyosarcomas and related sarcomas. Pathologic aspects and proposal for a new classification--an Intergroup Rhabdomyosarcoma Study.

BACKGROUND: There is a need to develop a single prognostically significant classification of rhabdomyosarcomas (RMS) and other related tumors of children, adolescents, and young adults which would be a current guide for their diagnosis, allow valid comparison of outcomes between protocols carried out anywhere in the world, and should enhance recognition of prognostic subsets. METHOD: Sixteen pathologists from eight pathology groups, representing six countries and several cooperative groups, classified by four histopathologic classification schemes 800 representative tumors of the 999 eligible cases treated on Intergroup Rhabdomyosarcoma Study II. Each tumor was classified according to each of the four systems by each of the pathologists. In addition, two independent subsamples of 200 of the 800 patients were reviewed according to the new system, so that 343 distinct patients were reviewed once, and 57 of these twice. RESULTS: A study of the survival rates of all subtypes in the sample of 800 patients led to the formation of a new system. This was tested on two independent subsets of 200 of the original cases and found to be reproducible and predictive of outcome by univariate analysis. A multivariate analysis of the 343 patients classified according to the new system indicated that a survival model including pathologic classification and known prognostic factors of primary site, clinical group, and tumor size was significantly better at predicting survival than a model with only the known prognostic factors. CONCLUSION: This new classification, termed International Classification of Rhabdomyosarcoma (ICR) by the authors, was reproducible and predictive of outcome among patients with differing histologies treated uniformly on the Intergroup Rhabdomyosarcoma II protocols. We believe it should be utilized by all pathologists and cooperative groups to classify rhabdomyosarcomas in order to provide comparability among and within multi-institutional studies.

Agreement among and within groups of pathologists in the classification of rhabdomyosarcoma and related childhood sarcomas. Report of an international study of four pathology classifications.

BACKGROUND: An International Pathology study was conducted to measure the agreement demonstrated among and within groups of pathologists involved in the categorization of childhood rhabdomyosarcoma according to four pathology classifications. Data concerning agreement and survival experience according to patho-new subtypes were used as a basis for selection of a proposed new pathologic classification. METHODS: A random sample of 800 eligible patients was chosen from the Intergroup Rhabdomyosarcoma Study II (IRS-II) and was reviewed by pathologists representing eight institutions. A 20% sample of the 800 patients was then reviewed by the pathologists to determine the level of agreement with their original classification. In each instance the patients were classified according to four pathology systems: the conventional system, the International Society for Pediatric Oncology system (SIOP), the National Cancer Institute (NCI) system, and the cytohistologic system. RESULTS: Among the groups of pathologists, the highest measure of agreement was a Kappa value of K = 0.451 for the conventional system, followed by K = 0.406 for the SIOP system, K = 0.384 for the NCI system, and K = 0.328 for the cytohistologic system. For reproducibility within the groups of pathologists, the highest measure of agreement was K = 0.605 for the conventional system, followed by K = 0.579 for the NCI system, K = 0.573 for the SIOP system, and K = 0.508 for the cytohistologic system. CONCLUSIONS: There was a general similarity between the agreement reached within the modified conventional, STOP, and NCI systems, with the modified conventional system having the highest Kappa values, and thus the highest measure of agreement, both among and within the groups of pathologists. Also, the subtypes of the conventional system demonstrated a highly significant relationship to survival time. Hence, based on criteria of reproducibilty and prognostic significance, the proposed classification will essentially be a modification of the conventional system with elements of the SIOP and NCI systems.

Epithelioid sarcoma in childhood: An immunohistochemical, electron microscopic, and clinicopathologic study of 11 cases under 15 years of age and review of the literature.

Epithelioid sarcoma in a rare tumor and most of the cases occur in young adults. It is rare in childhood. We have been able to obtain data and histologic material for 11 patients with this disease. The primary sites were head and neck in three patients, inguinal region in one, and extremities in seven. The age range of the patients was 12 weeks to 13 years. There was a preponderance of males over females with a ratio of 1.75. The tumors presented with a typical nodular necrotizing pattern. In three cases giant osteoclast-like cells were present. The immunohistochemistry and electron microscopy showed features consistent with previous observations on epithelioid sarcomas. In one case islands of small dark cells noted on light microscopy were surrounded by basal lamina on electron microscopy. The cells inside the nests were undifferentiated. Six tumors studied by flow cytometry were in DNA diploid range. On follow-up, five children are alive and well 2 to 7 years after treatment. Three children died of tumor progression with metastases to lymph nodes and lungs. One child had been diagnosed only recently, and in one the disease has run a protractive course with multiple recurrences. The behavior of these epithelioid sarcomas in children is similar to that seen in adults, the prognosis being dependent on radical tumor surgery preventing recurrent disease. Long-term follow-up is necessary because the tumor may recur many years after the primary tumor was removed.

Specific expression of insulin-like growth factor-II in rhabdomyosarcoma tumor cells.

Insulin-like growth factor II (IGF-II) acts as autocrine growth and motility factor in human rhabdomyosarcoma cell lines, and Northern blot analysis of tumor biopsy specimens from both alveolar and embryonal rhabdomyosarcoma demonstrates high levels of IGF-II mRNA expression. To determine the frequency and site of expression of IGF-II in these tumors, the authors performed in situ hybridization. All tumor specimens examined expressed the gene for IGF-II, and this expression was localized to the tumor cells themselves and not to the surrounding stroma. These data suggest that the IGF-II autocrine loop may be operating not only in vitro but also in vivo.

Tumor-cell DNA content predicts outcome in children and adolescents with clinical group III embryonal rhabdomyosarcoma. The Intergroup Rhabdomyosarcoma Study Committee of the Children's Cancer Group and the Pediatric Oncology Group.

PURPOSE: The prognostic value of tumor-cell DNA content (ploidy) was evaluated in children with unresectable, nonmetastic rhabdomyosarcoma of embryonal histology. PATIENTS AND METHODS: Flow-cytometric techniques were used to estimate the ploidy of tumor specimens from 34 patients with embryonal rhabdomyosarcoma who were enrolled in the intergroup rhabdomyosarcoma study III (IRS III) from 1985 to 1991. Tumors were classified as diploid or hyperdiploid (DNA content, 1.1 to 1.8 times that of normal diploid cells). The influence of ploidy on clinical outcome was assessed by the Kaplan-Meier technique and Cox regression analysis with stepwise selection. RESULTS: Twelve of the tumor specimens were diploid and 22 were hyperdiploid. The patient groups defined by diploid or hyperdiploid tumors had similar presenting characteristics (eg, age, tumor size, and anatomic site). Significantly more children with hyperdiploid tumors achieved a complete response than did children with diploid tumors (85% v 42%; P = .01). The probability of progression-free survival at 5 years (+/- SE) was 91% +/- 6% for the hyperdiploid group, compared with 17% +/- 11% for the diploid group (P < .001). Hyperdiploidy was also associated with a significantly higher overall survival rate at 5 years: 96% +/- 4% versus 50% +/- 14% (P = .004). Ploidy retained its prognostic significance after adjustment for tumor site in the Cox regression model. CONCLUSION: Tumor-cell ploidy strongly correlates with outcome in children with nonmetastic, unresectable embryonal rhabdomyosarcoma. The two biologically distinct groups identified by this measure would benefit from further refinements in risk-directed therapy.

Childhood rhabdomyosarcoma with anaplastic (pleomorphic) features. A report of the Intergroup Rhabdomyosarcoma Study.

The pleomorphic subtype of rhabdomyosarcoma (RMS) is now rarely diagnosed in both children and adults. Most cases previously called pleomorphic RMS are probably diagnosed as something else, most often embryonal RMS in children and malignant fibrous histiocytoma in adults. To analyze the concept of pleomorphic RMS in children, we reviewed the tumors of patients entered on the Inter-group Rhabdomyosarcoma Study (IRS I, II, and III). The presence of cells with lobated, hyperchromatic nuclei at least three times larger than the common tumor cell population (anaplastic cells) was selected as the main criterion. Of about 3,000 cases, 110 showed these types of cells, had sufficient histologic material, and had available follow-up data. These tumors were divided into two subgroups: Subgroup I tumors contained only scattered anaplastic cells, and tumors with foci or large sheets of anaplastic cells were classified as subgroup II. Besides the anaplastic-pleomorphic areas, most of these tumors had distinctive features of embryonal RMS (105 cases) and rarely had characteristics of alveolar RMS (five cases). The age distribution of these patients did not differ significantly from those whose tumors did not show the anaplastic features, the average being 6 years and the median 4 years. Lower extremity, retroperitoneum, and the head and neck region were the most common primary tumor sites. The 5-year survival rate was 60% for subgroup I tumors and 45% for subgroup II tumors compared with the survival rate of 68% for 482 IRS II embryonal RMS cases with no anaplastic-pleomorphic features. The lower survival rate for patients in subgroup II was statistically significant (p = 0.004) and similar to the unfavorable survival of patients with alveolar RMS and undifferentiated sarcoma. Because anaplastic cells are seen in many soft tissue sarcomas and in both embryonal and alveolar RMS in children, this feature is not sufficiently unusual to separate a pleomorphic subtype of RMS. The presence of anaplastic cells in aggregates or diffuse sheets throughout the tumor, however, portends a poor survival for these patients.

Sequelae of treatment in 109 patients followed for 5 to 15 years after diagnosis of sarcoma of the bladder and prostate. A report from the Intergroup Rhabdomyosarcoma Study Committee.

BACKGROUND: As increasing numbers of young patients with cancer survive, interest in the late effects of therapy is rising. METHODS: The sequelae of treatment were reviewed after a minimum of 5 years of observation in 109 surviving patients with sarcoma of the bladder or prostate who were enrolled in the Intergroup Rhabdomyosarcoma Studies I and II (1972-1984). The 82 male and 27 female patients were 3 weeks to 19 years of age when the diagnosis was made (median, 2 years) and were 5-29 years of age at last contact (median, 11 years). Treatment consisted of chemotherapy with vincristine, dactinomycin, and cyclophosphamide and bladder irradiation in nearly all patients. RESULTS: Fifty-four patients underwent total cystectomy, and 10 had a partial cystectomy. Of the 55 patients with bladder preservation, 1 had a urinary conduit with a nonfunctioning bladder. Thus, 54 bladders (50% of the total) remained in place as part of the urinary tract. There was no information regarding bladder function in two patients. Satisfactory bladder function was found in 38 patients (73%), 9 were incontinent, and 5 had urinary frequency with or without nocturia. Posttherapy hematuria was detected in 29% of patients. Nine of the 31 patients (29%) with follow-up renal imaging studies had a structural abnormality, chiefly hydronephrosis, which was more frequent in those with urinary diversion. Positive urine cultures were found mainly among those with enteric urinary conduits, but only two cases of pyelonephritis were documented. Abnormalities of irradiated bone and bowel were observed infrequently. Only one patient had a significantly elevated blood urea nitrogen or serum creatinine value, and only one patient was hypertensive. Most patients were still prepubertal at last follow-up. Of 24 patients who were intrapubertal or postpubertal, 7 (29%) were receiving sex hormone replacement because of delayed pubertal development. Height was decreased by 25% or more in 11 patients, as confirmed by growth chart analysis. Secondary surgical procedures other than repeat biopsy or cystectomy consisted primarily of urinary conduit revisions and repair of bowel adhesions or fistulous tracts. Information about psychosocial status was limited. CONCLUSIONS: Overall, 50% of the patients retained their bladders, and 73% of them had satisfactory bladder function. Renal function was preserved in nearly every patient.

Spindle cell variants of embryonal rhabdomyosarcoma in the paratesticular region. A report of the Intergroup Rhabdomyosarcoma Study.

We reviewed 173 cases of paratesticular rhabdomyosarcoma (RMS) of Intergroup Rhabdomyosarcoma Studies (IRS)-I, -II, and -III for evaluation of possible histological factors that might account for the good prognosis of these patients. Almost all cases (161 of 173 cases, 93.1%) occurring in this site were of embryonal histology. A spindle-cell subtype of embryonal RMS was identified that presented a storiform growth pattern with abundant collagen between the tumor cells in most cases. Other tumors of this subtype showed an arrangement of tumor cells in bundles with a low to moderate amount of collagen, resembling a leiomyosarcoma. The other embryonal RMS in this site had the classical embryonal cytology. The spindle-cell subtype was highly differentiated by immunohistochemistry and electron microscopy. Lymph node metastasis was found in seven of 43 patients (16.3%) with a RMS of spindle-cell subtype, compared with 40 of 112 patients (35.7%) with RMS of non-spindle-cell type. Clinical data from patients with spindle-cell subtypes of the paratesticular lesions revealed that they almost always had an association with clinical groups of limited disease (32 patients, 74.4%, with Group I; 10 patients, 23.3%, with Group II disease) and a significantly better prognosis (95.5% survival at 5 years) when compared with patients with the classic embryonal variant of RMS (80% survival at 5 years, p < 0.035). The incidence and anatomic distribution of this spindle cell subtype of embryonal RMS was estimated on 800 randomly selected patients from IRS-II. It was found in the head and neck, extremities, orbit, and some other sites, but 30.6% were located in the paratesticular area. Patients with spindle cell RMS of nonparatesticular sites usually had more extensive disease compared with patients having paratesticular lesions; two thirds of the cases had gross residual tumor after surgery or metastatic tumor at diagnosis. We conclude that spindle-cell RMS is a subtype of embryonal RMS with a very favorable prognosis. The site factor of the paratesticular localization may allow earlier diagnosis of the spindle-cell lesions compared with other sites. Other unknown factors may also play a role.

Second malignant neoplasms in children treated for rhabdomyosarcoma. Intergroup Rhabdomyosarcoma Study Committee.

PURPOSE: This study was performed to determine the incidence and risk factors involved in the development of a second malignant neoplasm (SMN) after treatment of primary rhabdomyosarcoma (RMS) in patients enrolled onto Intergroup Rhabdomyosarcoma Studies I and II (IRS I and II). PATIENTS AND METHODS: There were 1,770 patients with primary RMS entered onto IRS I and II between 1972 and 1984. They were treated with chemotherapy and, in most instances, radiotherapy according to randomized or assigned regimens based on clinical grouping. Median follow-up time for these patients was 8.4 years. Incidence density (ID) was calculated for each study and for treatment and age groups. The 10-year cumulative incidence was estimated for each study. RESULTS: Twenty-two SMNs have been reported through 1991. The most common tumor type was a bone sarcoma followed by acute nonlymphoblastic leukemia (ANLL). The median time to the development of an SMN was 7 years (range, 1 11/12 to 15 9/12 years). The 10-year cumulative incidence rate was 1.7% for both studies. ID and cumulative incidence estimates were highest for patients who received both an alkylating agent and radiotherapy. The majority of patients for whom family histories were available had either neurofibromatosis themselves or a family history that suggested the Li-Fraumeni syndrome (LFS). CONCLUSION: The results of this study suggest that genetic abnormalities play a prominent role in the development of an SMN after therapy for a primary RMS. Chemotherapy with an alkylating agent and radiotherapy play significant roles in the development of an SMN compared with patients who received only one of these therapeutic modalities.