Presence of well-differentiated rhabdomyoblasts at the end of therapy for pelvic rhabdomyosarcoma: implications for the outcome

Local treatment of rhabdomyosarcoma of the female genital tract: Expert consensus from the Children's Oncology Group, the European Soft-Tissue Sarcoma Group, and the Cooperative Weichteilsarkom Studiengruppe

The International Soft-Tissue Sarcoma Consortium (INSTRuCT) was founded as an international collaboration between different pediatric soft-tissue sarcoma cooperative groups (Children's Oncology Group, European Pediatric Soft-Tissue Sarcoma Group, and Cooperative Weichteilsarkom Studiengruppe). Besides other tasks, a major goal of INSTRuCT is to develop consensus expert opinions for best clinical treatment. This consensus paper for patients with rhabdomyosarcoma of the female genital tract (FGU-RMS) provides treatment recommendations for local treatment, long-term follow-up, and fertility preservation. Therefore, a review of the current literature was combined with recommendations of the treatment protocols of the appropriate clinical trials. Additionally, opinions of international FGU-RMS experts were incorporated into recommendations. Results were that the prognosis of FGU-RMS is favorable with an excellent response to chemotherapy. Initial complete surgical resection is not indicated, but diagnosis should be established properly. In patients with tumors localized at the vagina or cervix demonstrating incomplete response after induction chemotherapy, local radiotherapy (brachytherapy) should be carried out. In patients with persistent tumors at the corpus uteri, hysterectomy should be performed. Fertility preservation should be considered in all patients. In conclusion, for the first time, an international consensus for the treatment of FGU-RMS patients could be achieved, which will help to harmonize the treatment of these patients in different study groups.

Can 18 F-FDG-Positron Emission Tomography be a Prognostic Tool in Children With Rhabdomyosarcoma Treated With Definitive Radiotherapy?

BACKGROUND

Persisting residual masses at treatment completion are known in rhabdomyosarcoma (RMS) treated with definitive radiotherapy (RT) to the primary site, but their prognostic significance is uncertain. Tumor response as assessed by anatomic imaging is not prognostic and studies based on 18 F-FDG-PET response are limited. We report the prognostic significance of persistent FDG-avidity in residual masses, assessed 3-month postdefinitive RT, in pediatric RMS.

MATERIALS AND METHODS

Children 15 years old or below with Group III/IV RMS who received only definitive radiotherapy for local control from June 2013 to December 2018, and had 18 F-FDG-PET CT at 3 months post-RT were retrospectively analyzed for outcomes and other prognostic factors.

RESULTS

Sixty-three children were eligible (Group III-55, Group IV-8). 18 F-FDG-PET CT scan done 3 months postradiotherapy showed FDG-avid residual masses in 10 patients (15.9%), anatomic residual in 24 (38.1%), and no anatomic/FDG-avid residual in 29(46.0%). At a median follow-up of 38 months (interquartile range, 24 to 55 mo), 3-year EFS of patients with FDG-avid residual masses was 40.0% (95% CI: 18.7% to 85.5%) versus the rest of the cohort, which was 71.9% (95% CI: 59.8% to 86.5%) ( P =0.008). Three-year OS of patients with FDG-avid residual masses was 50.8% (95% CI: 25.7% to 100.0%) versus the rest of the cohort, which was 77.0% (95% CI: 65.1% to 91.0%) ( P =0.037). Presence of FDG-avid residual disease persisting post-RT affected both EFS [HR-3.34 (95% CI: 1.29 to 8.68) ( P =0.013)] and OS [HR-3.20 (95% CI: 1.01 to 10.12) ( P =0.048)] on univariate analysis and this significance was retained for EFS in multivariate analysis [HR-3.52 (95% CI: 1.33 to 9.30) ( P =0.011)].

CONCLUSIONS

Persistent metabolic activity in residual disease post-chemoradiotherapy in RMS may portend a poorer prognosis with an increased risk of relapse. This subset of high-risk patients needs to be identified, and further trials are warranted to develop strategies to improve their outcomes.

Radioresistance in rhabdomyosarcomas: Much more than a question of dose

Management of rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children, frequently accounting the genitourinary tract is complex and requires a multimodal therapy. In particular, as a consequence of the advancement in dose conformity technology, radiation therapy (RT) has now become the standard therapeutic option for patients with RMS. In the clinical practice, dose and timing of RT are adjusted on the basis of patients' risk stratification to reduce late toxicity and side effects on normal tissues. However, despite the substantial improvement in cure rates, local failure and recurrence frequently occur. In this review, we summarize the general principles of the treatment of RMS, focusing on RT, and the main molecular pathways and specific proteins involved into radioresistance in RMS tumors. Specifically, we focused on DNA damage/repair, reactive oxygen species, cancer stem cells, and epigenetic modifications that have been reported in the context of RMS neoplasia in both in vitro and in vivo studies. The precise elucidation of the radioresistance-related molecular mechanisms is of pivotal importance to set up new more effective and tolerable combined therapeutic approaches that can radiosensitize cancer cells to finally ameliorate the overall survival of patients with RMS, especially for the most aggressive subtypes.

Embryonal Rhabdomyosarcoma with Posttherapy Cytodifferentiation and Aggressive Clinical Course

Rhabdomyosarcoma is the most common soft tissue sarcoma in children and adolescents. Embryonal rhabdomyosarcoma (ERMS), its most common subtype, is a malignant soft tissue tumor with morphologic and immunophenotypic features of embryonic skeletal muscle. The histologic findings in ERMS typically include a range of differentiation in rhabdomyoblasts from primitive to terminally differentiated forms, and the latter become more prominent after chemotherapy-induced cytodifferentiation. Several reports have shown therapy-related cytodifferentiation to portend a good prognosis in ERMS. We discuss the case of a pediatric patient who presented with ERMS of the orbit. Although her tumor showed extensive posttreatment cytodifferentiation and several other good prognostic clinicopathologic factors, it pursued an aggressive course, resulting in early metastasis and death. This case represents an unusual course and may be instructive as to the clinicopathologic features impacting prognostication, and ultimately the biology, of this aggressive family of tumors.

Relationship between tumor response at therapy completion and prognosis in patients with Group III rhabdomyosarcoma: A report from the Children's Oncology Group

A subset of patients with initially unresected (Clinical Group III) rhabdomyosarcoma achieve less than a complete response (CR) despite multimodal therapy. We assessed outcome based upon tumor response at the completion of all planned therapy. We studied 601 Clinical Group III participants who completed all protocol therapy without developing progressive disease on two Children's Oncology Group studies ARST0531 (n = 285) and D9803 (n = 316). Response was defined by imaging and categorized by response; complete resolution (CR), partial response (PR) or no response (NR). Failure-free survival (FFS) and overall survival (OS) between response groups were compared using the log-rank test. We found that radiographic response was CR in 393 (65.4%) and PR/NR in 208 (34.6%) patients. Achieving CR status was associated with study D9803, nonparameningeal (PM) primary sites, tumors ≤5 cm, noninvasive tumors and alveolar histology/FOXO fusion-positive tumors. The overall 5-year FFS was 75% for those achieving CR and 66.5% in those with PR/NR (adj. p = 0.094). Patients with PM primary site who achieved CR had significantly improved FFS (adj. p = 0.037) while those with non-PM primary sites had similar outcomes (adj. p = 0.47). Radiographic response was not associated with OS (adj. p = 0.21). Resection of the end-of-therapy mass did not improve FFS (p = 0.12) or OS (p = 0.37). In conclusion, CR status at the end of protocol therapy in patients with PM Clinical Group III RMS was associated with improved FFS but not OS. Efforts to understand the biology and treatment response in patients with PM primary site are under investigation.

Chemoradiotherapy-induced Cytodifferentiation in Bladder/Prostate Rhabdomyosarcoma With Genetic Downregulation of Myogenin and MyoD1 Gene Expression: A Case Study and Review of the Literature

Rhabdomyosarcoma is the most common sarcoma diagnosed in childhood and adolescence, arising from the bladder/prostate in only 5%-10% of cases. Treatment-induced cytodifferention of tumor cells into mature rhabdomyoblasts has been reported following chemoradiation and is thought to suggest a more favorable outcome. We report a case of embryonal rhabdomyosarcoma of the bladder/prostate that exhibited extensive cytodifferentiation with downregulation of myogenin and MyoD1 gene expression in rhabdomyoblasts following treatment with chemoradiation therapy. The downregulation of myogenin and MyoD1 expression in rhabdomyoblasts following chemoradiation treatment has not previously been described in the literature and its significant remains uncertain.

Current Treatment of Pediatric Bladder and Prostate Rhabdomyosarcoma

PURPOSE OF REVIEW

Rhabdomyosarcoma (RMS) is the most common sarcoma diagnosed in the first 20 years of life; bladder/prostate (BP) RMS accounts for 5% of all cases. Through efforts from multiple cooperative study groups, survival has improved significantly. This article aims to review the complex RMS classification system and treatment of BP RMS, with a focus on developing aspects of treatment.

RECENT FINDINGS

Recent advancements in technology are responsible for most of the progress in RMS treatment. PET-CT scanning has been shown to be superior to conventional metastatic workup. The use of proton beam therapy and brachytherapy to reduce the side effects of radiation is also showing promise. All cooperative oncology groups agree on surgical biopsy for diagnosis and staging of BP RMS. Patients are then grouped and risk classified before receiving chemotherapy. Regardless of local control strategy, oncologic outcomes appear to be similar for BP RMS. Alternative treatment strategies, which remain unproven, include brachytherapy and proton therapy.

High-dose-rate brachytherapy for vaginal rhabdomyosarcoma using a personalized mold in a 20-month old patient

Treatment of vaginal rhabdomyosarcoma (RMS) with conservative approaches is presently the standard of care. Intravaginal high-dose rate brachytherapy is a very effective treatment while sparing the normal tissue to preserve growth, fertility and prevent organ dysfunction. In this report, we describe the management of an infant with Stage I vaginal RMS, treated with chemotherapy, maximal safe resection and intravaginal brachytherapy using a customized mold and MRI and CT-based three-dimensional (3D) conformal planning, followed by a critical review of the literature.

Primary embryonal rhabdomyosarcoma of the anterior neck and thyroid: report of a new case with review of the literature

Primary embryonal rhabdomyosarcoma of anterior neck involving the thyroid is extremely rare. This report is only the second of its kind that describes this form of nonorbital nonparameningeal rhabdomyosarcoma in a 7-year-old boy and adds to a new, seldom-reported variant of rhabdomyosarcoma in the head-neck region. The child presented with a huge anterior neck swelling that clinically resembled a thyroid mass. Computed tomography scan showed a heterogeneous mass in the anterior neck replacing the entire right lobe of thyroid. Fine-needle aspiration cytology was nondiagnostic. Right hemithyroidectomy with selective neck dissection suggested embryonal rhabdomyosarcoma by histopathology; the diagnosis was confirmed by positive reactions to desmin and myogenin. The child was subsequently treated with chemotherapy. Repeat chemotherapy with radiotherapy was required when recurrences were detected in the mediastinum and cervical lymph nodes at 13-month follow-up.

The surgical management of paediatric bladder and prostate rhabdomyosarcoma

BACKGROUND

The surgical management of paediatric bladder/prostate rhabdomyosarcoma (B/P RMS) continues to develop, with the goal of maximising organ preservation while achieving successful cancer control. The timing of radiotherapy and surgical excision to improve event-free survival (EFS) and overall survival (OS) remains controversial.

METHODS

Previous reports in English on B/P RMS over the past 15 years were identified and reviewed, focusing on studies comparing the effects of radiotherapy and surgery for local control, the effect of local control on OS, and improved means of diagnosing viable tumour after chemotherapy.

RESULTS

The concept of lowering the 'cost of cure' drives current protocols. Bladder-sparing surgery is possible for 80% of patients after initial chemotherapy, with a mean 5-year OS of 85%. Overall, half of the patients are continent of urine, and adding radiotherapy might increase the risk of incontinence. Previous studies suggesting that early radiotherapy achieved better EFS than delayed radiotherapy did not control for stage and size of the tumour, which are the primary determinants of EFS. Improved local control does not automatically translate into improved OS.

CONCLUSIONS

The current role for the surgical management in B/P RMS is to achieve local control of tumours that do not respond to chemotherapy and radiotherapy. An improved means of detecting viable tumour after initial chemotherapy would improve the ability to decide when local therapy is necessary. The continuing challenge for urologists managing these children is knowing when bladder-sparing surgery would be the best therapy.

Effects of neoadjuvant chemotherapy on hepatoblastoma: a morphologic and immunohistochemical study

Neoadjuvant chemotherapy followed by resection has become the mainstay in the treatment of hepatoblastoma (HB). The changes after chemotherapy typically result in tumor necrosis and a fibrohistiocytic response. We have observed that treated HBs undergo additional morphologic changes that have not been described. Herein, we report a 15-year retrospective study of HBs in 22 children who received neoadjuvant chemotherapy according to the Children's Oncology Group protocols. The medical records, diagnostic imaging, and histopathology were reviewed. Besides treated HBs having characteristic necrosis and fibrohistiocytic response, two-thirds had areas of cytoarchitectural differentiation ("maturation") mimicking non-neoplastic liver, and a quarter had alterations mimicking hepatocellular carcinoma. Nuclear expression of beta-catenin and keratin profiles were useful in distinguishing residual tumor with "maturation" from non-neoplastic liver and therefore in the assessment of surgical margins. Statistical analysis revealed that larger pretreatment and posttreatment imaged tumor size, larger tumor size at pathologic examination, and vascular invasion were significant univariate predictors of metastatic disease, whereas pretreatment imaged tumor size and vascular invasion were also significant independent predictors (multivariate logistic regression analysis). Multifocality, greater posttreatment necrosis and hepatocellular carcinoma-like morphology were more often associated with metastatic disease, but did not reach statistical significance.

Genitourinary rhabdomyosarcoma: which treatment, how much, and when?

OBJECTIVE

To review the current management of pediatric genitourinary rhabdomyosarcoma (RMS).

METHODS

Studies performed by the Intergroup Rhabdomyosarcoma Study Group, Children's Oncology Group (COG), International Society of Paediatric Oncology (SIOP) and others over the past 10 years were reviewed to compare the use of surgery, chemotherapy, and radiotherapy for treatment of RMS and their associated outcomes.

RESULTS

Equivalent overall survival rates were reported in the last COG and SIOP trials, with worse event-free survival rates for bladder/prostate RMS in SIOP trials. The use of radiotherapy for local control was the main difference between current COG and SIOP protocols. Surgery is used to diagnose RMS, and for local control after chemotherapy. Chemotherapy is used for systemic control of RMS, but metastatic RMS will require new approaches.

CONCLUSION

Risk stratification and risk-based therapy are being studied to decrease morbidity from treatment of RMS. The proper role of surgery vs radiotherapy for local control and whether additional treatment with second-line chemotherapy outweighs the avoidance of radiotherapy remain to be defined.

Differentiated rhabdomyomatous tumors after chemotherapy for metastatic testicular germ-cell tumors: a clinicopathological study of seven cases mandating separation from rhabdomyosarcoma

To gain insight concerning prognosis, we investigated seven cases of post-chemotherapy retroperitoneal lymph-node dissections from patients with testicular germ-cell tumors that contained sizable nodules of differentiated skeletal muscle, but that lacked both a primitive cellular component and mitotic activity. The patients were 18-28 years old at the time of retroperitoneal lymph-node dissection. All had a previous non-seminomatous germ-cell tumor of the testis, five of which had a teratoma component. In one the testicular tumor had foci of embryonal rhabdomyosarcoma. The retroperitoneal lymph-node dissections were performed 0.2-4.7 years after orchiectomy, all following cisplatin-based chemotherapy, and contained rhabdomyomatous tumors that ranged from 0.8-5 cm. These consisted of nodular to diffuse aggregates of fetal-type rhabdomyocytes with central to peripheral nuclei and abundant, eosinophilic, fibrillary cytoplasm with occasional cross striations. Elongated myotubes with multiple nuclei in a common sarcoplasm occurred at least focally in all cases. Mild to moderate nuclear atypia, including nuclear enlargement and nucleolar prominence, was present, but mitotic activity, necrosis, and a primitive cellular component were absent. All but one retroperitoneal lymph-node dissection also contained other teratomatous elements. Follow-up in six patients showed three were disease free at 2.2-3.4 years; two developed recurrent teratoma at 1.3-3.7 years; and a sixth developed recurrent teratoma at 0.5 and 2 years, followed at 17 years by progressive tumor with elevated alpha-fetoprotein. No patient with available follow-up developed progressive sarcoma. We conclude that rhabdomyomatous tumors in retroperitoneal lymph-node dissection specimens after chemotherapy for metastatic testicular germ-cell tumors show clinical behavior similar to teratoma rather than rhabdomyosarcoma. We believe the most likely explanation for the finding of pure rhabdomyomatous tumors in this setting, a phenomenon sometimes termed 'cytodifferentiation,' is selective persistence of differentiated tumor cells because of chemotherapy.

Prognostic significance of tumor response at the end of therapy in group III rhabdomyosarcoma: a report from the children's oncology group

PURPOSE

Some patients with rhabdomyosarcoma (RMS) achieve less than a complete response (CR) despite receiving all planned therapy. We assessed the impact of best response at the completion of all therapy on patient outcome.

PATIENTS AND METHODS

We studied 419 clinical group III participants who completed all protocol therapy without developing progressive disease for Intergroup Rhabdomyosarcoma Study (IRS) IV. Response (complete resolution [CR], partial response [PR; > or = 50% decrease], or no response [NR; < 50% decrease and < 25% increase]) was determined by radiographic measurement and categorized by the best response.

RESULTS

At the end of therapy, 341 participants (81%) achieved a best response of CR and 78 (19%) had a best response of PR/NR. Five-year failure-free survival was similar for participants achieving CR (80%) and PR/NR (78%). After adjustment for age, nodal status, primary site, and histology, there was no significant indication of lower risk of failure (hazard ratio [HR], 0.77; 95% CI, 0.46 to 1.27; P = .3) nor death (HR, 0.63; 95% CI, 0.36 to 1.09; P = .1) for CR versus PR/NR participants. Seventeen participants with a best response of PR/NR had surgical procedures; eight (50%) of 16 with available pathology reports had residual viable tumor and only three achieved a complete resection. Resection of residual masses was not associated with improved outcome.

CONCLUSION

CR status at the end of protocol therapy in clinical group III participants was not associated with a reduction of disease recurrence and death. Aggressive alternative therapy may not be warranted for RMS patients with a residual mass at the end of planned therapy.

Conservative surgery plus brachytherapy treatment for boys with prostate and/or bladder neck rhabdomyosarcoma: a single team experience

PURPOSE

The aim of this study is to report the results of a conservative surgery + brachytherapy treatment for boys with prostate and/or bladder-neck rhabdomyosarcoma avoiding total cystectomy or prostatectomy and external radiotherapy.

PATIENTS

From 1991 to 2007, 26 boys were operated for a residual mass after chemotherapy (1 for local relapse). All patients underwent a conservative surgical procedure, with bladder-neck and urethra preservation. Surgery was never microscopically complete. Brachytherapy was systematically performed after tumor resection, as a perioperative procedure, consisting of 2 loops encompassing the prostate and the bladder-neck area. A dose of 60 Gy was delivered with low dose rate. Bladder function was evaluated clinically and with urodynamic study for boys with abnormal continence.

RESULTS

Median age at operation was 23 months (9 months-11 years). Seventeen boys underwent a partial prostatectomy associated in 5 with a partial cystectomy. The remaining 9 patients underwent a partial cystectomy with no procedure at the level of the prostate. At a median follow-up of 4 years (10 months-14.5 years), 24 of 26 boys are alive. Only 1 patient relapsed locally out of the brachytherapy field and died. A second boy died from metastatic relapse. Only 1 patient with bladder dysfunction after treatment underwent a total cystectomy. Four patients are too young to be evaluated for bladder function (<4 years of age). Seven patients, aged 4 to 6 years, have daytime continence, 1 has diurnal dribbling. Among 11 boys older than 6 years, 9 (82%) are normally continent (3 after temporary dribbling), 2 have diurnal dribbling treated by bladder education.

CONCLUSION

Even if very long-term sequelae of brachytherapy cannot be evaluated, this conservative combined treatment may allow normal continence in nearly all patients, even after temporary diurnal incontinence and should be discussed as an alternative to external radiotherapy or radical surgery.

Nonepithelial Tumors and Tumor-Like Lesions of the Prostate Gland

Many significant benign and malignant nonepithelial tumors and stromal tumor-like lesions arise in the prostate gland. Although such lesions are rare, their recognition by the pathologist is essential because their treatment and prognosis are quite variable. In this review, lesions of the specialized prostatic stroma, that is, lesions that can be seen in the stroma of the prostate but not in that of other organs, except for the phyllodes type of lesions, are discussed. Benign and malignant lesions of the soft tissues that occur in the stroma of other organs and are seen with some frequency in the prostate are also discussed. Few of the rarer soft tissue lesions are mentioned. Lesions and tumors with melanocytic differentiation, hematopoietic derivation, and germ cell tumors are described. It is hoped that this review will serve as a useful reference when encountering some of these lesions, all of which are referenced to their original and subsequent reports. Some non-English language references are also cited to reflect the international recognition of these lesions or to give credit to the author who first described the entity.

Bladder/Prostate Rhabdomyosarcoma: Past, Present and Future

PURPOSE

The last few decades have witnessed substantial improvement in outcomes in children with bladder/prostate rhabdomyosarcoma. We reviewed relevant historical aspects of treatment, current treatment strategies and new developments. Most importantly we identified areas of existing controversy, which will provide direction for future studies and continued improvements in therapy.

MATERIALS AND METHODS

A database (PubMed, MEDLINE, etc) search was performed from 1966 through January 2005. Approximately 500 citations were identified. Relevant citations were reviewed in detail.

RESULTS

While the reported cure rate has improved to approximately 70% to 80% and bladder preservation rates as high as 60% are reported, substantial controversy continues in certain areas. Specifically the long-term function of preserved bladders, the contribution of radiotherapy to bladder dysfunction, the timing of reconstruction and molecular markers of disease progression are among the areas that require further investigation.

CONCLUSIONS

Substantial progress has been made as a result of multi-institutional collaborative trials. Future combined studies are required to further the treatment of this childhood malignancy.

Significance of persistent mature rhabdomyoblasts in bladder/prostate rhabdomyosarcoma: Results from IRS IV

Terminally differentiated rhabdomyoblasts are common after or during therapy for rhabdomyosarcoma (RMS). Case reports have suggested that their presence after therapy does not indicate a poor prognosis, but significance and relationship to outcome has not been systematically studied. Management of patients with this finding can cause confusion. Slides and pathology reports from 44 patients with bladder/prostate RMS treated on Fourth Intergroup Rhabdomyosarcoma Study were examined by a pathologist experienced in RMS, and findings compared with institutional reports. Details regarding patient characteristics, outcome, and management were reviewed. Outcome of patients with various pathologic findings was assessed. One of 10 patients with only mature rhabdomyoblasts at their last procedure recurred, versus 4 of 17 patients with viable tumor and 2 of 17 patients with no viable tumor and no rhabdomyoblasts. Sixteen of 42 cases reviewed had results differing from our review. Mature rhabdomyoblasts are a discrete entity which may not be predictive of recurrence, but should be evaluated by a pathologist experienced with this entity. The presence of mature rhabdomyoblasts at the end of therapy for bladder/prostate RMS does not justify radical surgery. Sequential biopsies are subject to sampling error and should only be performed in the context of protocol-directed therapy to avoid unnecessary radical surgeries.

Pediatric urologic oncology: bladder, prostate, testis

Although treatment for bladder, prostate, and testis cancer comprises a large part of adult urologic practice, the tumors that affect these organs in children are rare. Rhabdomyosarcoma,which affects the bladder, prostate, vaginal, and paratesticular areas,is treated with a combination of surgery, chemotherapy, and radiation. Most transitional cell carcinomas of the bladder and prepubertal testis tumors are managed surgically owing to the low stage at presentation. Application of the technical advances learned in adults with tumors of the bladder, prostate, and testis, combined with an understanding of the difference in tumor biology, helps urologists improve the treatment of these tumors in children.

DOES BLADDER PRESERVATION (AS A SURGICAL PRINCIPLE) LEAD TO RETAINING BLADDER FUNCTION IN BLADDER/PROSTATE RHABDOMYOSARCOMA? RESULTS FROM INTERGROUP RHABDOMYOSARCOMA STUDY IV

PURPOSE

We determine patient and tumor characteristics, event-free and overall survival, methods of local control, rate of bladder preservation and proportion with normal bladder function for patients with localized bladder/prostate (BP) rhabdomyosarcoma (RMS) treated on the Fourth Intergroup Rhabdomyosarcoma Study (IRS IV).

MATERIALS AND METHODS

We reviewed the records of 90 patients with nonmetastatic BP RMS enrolled on IRS IV for presenting characteristics, details of therapy and outcome.

RESULTS

Of the 90 records 88 had sufficient information for review. Patient age distribution was less than 1 year for 7 patients, 1 to 9 years for 71 and 10 or greater years for 10. Tumors commonly arose in the bladder (70%), had favorable histology (embryonal or botryoid 80%), large (69% greater than 5 cm), unresectable (84% group III) and invasive (56% T2). Local therapy included radiation in 74 patients, and most patients underwent second-look operations after radiation. All patients received alkylating based chemotherapy. With a median followup of 6.1 years there have been 3 second malignancies, 1 toxic death and 18 relapses, for an event-free survival rate of 77%. Bladders were retained without relapse at last contact in 55 patients. Of those 55 patients 36 and of the entire group 40% had normal function determined by history.

CONCLUSIONS

Of patients with nonmetastatic BP RMS on IRS IV 82% survived 6 years. Bladder function was preserved in 55% (36/66) of event-free survivors. Of all patients entered on study 40% (36 of 88) survive event-free with apparently normal functioning bladders. More precise long-term evaluation of bladder and sexual function will require application of better tools such as urodynamic studies and validated patient surveys.

Treatment modalities of bladder/prostate rhabdomyosarcoma: a review

Treatment outcomes of bladder/prostate rhabdomyosarcoma (RMS) in multi- and single-institutional trials are reviewed. Remarkable strides have occurred in the treatment of this disease. Decreasing duration of chemotherapy, less cumulative doses of radiation therapy, and improving survival have been documented. A focus on bladder preservation has not adversely affected survival in most studies. Even if organ preservation is not possible, improvements in urinary diversion surgical technique still offer improved quality of life. The IRS III was a pivotal study in improving survival and quality of life. We recommend protocol enrollment whenever available. We also emphasize the use of magnetic resonance imaging and second look surgery.

Cytodifferentiation and clinical outcome after chemotherapy and radiation therapy for rhabdomyosarcoma (RMS)

BACKGROUND

Second-look surgery after therapy for rhabdomyosarcoma (RMS) may yield prognostic information regarding tumor responsiveness to treatment. Favorable outcome is suggested by tumor cells which have undergone maturation (cytodifferentiation).

PROCEDURE

Specimens from patients treated on Intergroup RMS Study-IV (IRSG-IV) were studied before and after treatment. All patients received chemotherapy and most received radiation therapy. Post-treatment specimens were graded according to the quantity of tumor showing cytodifferentiation (0 = absent, 1 = mild, 2 = moderate, 3 = extensive). Proliferative activity by MIB-1, topoisomerase II-alpha, and p53 protein expression were measured.

RESULTS

19/31 cases from IRSG-IV were adequate for analysis. Six out of nineteen patients failed therapy within 1.3 years of treatment. Grade 3 cytodifferentiation was present in 10 cases (2 BRMS, 8 ERMS); none failed therapy. Grade 2 cytodifferentiation was present in 5 cases (1 ERMS, 2BRMS, 2ARMS); 2 patients with ARMS failed therapy. Grade 0-1 cytodifferentiation was present in 4 cases (1 ERMS and 3 ARMS); all failed therapy. Proliferative activity by MIB-1 and topoisomerase II-alpha immunohistochemistry decreased or was unchanged after treatment for all ERMS/BRMS, and 4/5 cases of ARMS. p53 immunohistochemistry showed no consistent pattern of reactivity. Sparse persistent tumor cells were present in 9/10 ERMS, 3/4 BRMS, 5/5 ARMS.

CONCLUSIONS

Extensive cytodifferentiation is more commonly seen in ERMS/BRMS compared with less evidence for cytodifferentiation in ARMS suggesting fundamentally different mechanisms of cellular response to therapy in RMS. Sparse persistent tumor cells in post treatment ERMS/BRMS specimens does not appear to affect outcome.