High-dose therapy with hematopoietic stem cell rescue in patients with poor prognosis Ewing family tumors

High-dose chemotherapy for Ewing sarcoma and Rhabdomyosarcoma: A systematic review by the Australia and New Zealand sarcoma association clinical practice guidelines working party

INTRODUCTION

Patients with high-risk or metastatic Ewing sarcoma (ES) and rhabdomyosarcoma (RMS) have a guarded prognosis. High-dose chemotherapy (HDT) with autologous stem cell transplant (ASCT) has been evaluated as a treatment option to improve outcomes. However, survival benefits remain unclear, and treatment is associated with severe toxicities.

METHODS

A systematic review was conducted, using the population, intervention, comparison outcome (PICO) model, to evaluate whether utilization of HDT/ASCT impacts the outcome of patients with ES and RMS compared to standard chemotherapy alone, as part of first line treatment or in the relapse setting. Medline, Embase and Cochrane Central were queried for publications from 1990 to October 2022 that evaluated event-free survival (EFS), overall survival (OS), and toxicities. Each study was screened by two independent reviewers for suitability. A qualitative synthesis of the results was performed.

RESULTS

Of 1,172 unique studies screened, 41 studies were eligible for inclusion with 29 studies considering ES, 10 studies considering RMS and 2 studies considering both. In ES patients with high-risk localised disease who received HDT/ASCT after VIDE chemotherapy, consolidation with melphalan-based HDT/ASCT as first line therapy conveyed an EFS and OS benefit over standard chemotherapy consolidation. Efficacy of HDT/ASCT using a VDC/IE backbone, which is now standard care, has not been established. Survival benefits are not confirmed for ES patients with metastatic disease at initial diagnosis. For relapsed/refractory ES, four retrospective studies report improvement in outcomes with HDT/ASCT with the greatest evidence in patients who demonstrate a treatment response before HDT, and in patients under the age of 14. In RMS, there is no proven survival benefit of HDT/ASCT in primary localised, metastatic or relapsed disease.

CONCLUSION

Prospective randomised trials are required to determine the utility of HDT/ASCT in ES and RMS. Selected patients with relapsed ES could be considered for HDT/ASCT.

Ewing Sarcoma Drug Therapy: Current Standard of Care and Emerging Agents

Ewing sarcoma is a translocation-associated sarcoma mainly impacting adolescents and young adults. The classic translocation (EWSR1::FLI1) leads to a fusion oncoprotein that functions as an aberrant transcription factor. As such, the oncogenic driver of this disease has been difficult to target pharmacologically and, therefore, the systemic therapies used to treat patients with Ewing sarcoma have typically been non-selective cytotoxic chemotherapy agents. The current review highlights recent clinical trials from the last decade that provide the evidence base for contemporary drug therapy for patients with Ewing sarcoma, while also highlighting novel therapies under active clinical investigation in this disease. We review recent trials that have led to the establishment of interval-compressed chemotherapy as an international standard for patients with newly diagnosed localized disease. We further highlight recent trials that have shown a lack of demonstrable benefit from high-dose chemotherapy or IGF-1R inhibition for patients with newly diagnosed metastatic disease. Finally, we provide an overview of chemotherapy regimens and targeted therapies used in the management of patients with recurrent Ewing sarcoma.

High-dose chemotherapy followed by autologous haematopoietic cell transplantation for children, adolescents, and young adults with primary metastatic Ewing sarcoma

BACKGROUND

Ewing sarcomas are solid tumours of the bone and soft tissue, that usually affect children, adolescents, and young adults. The incidence is about three cases per million a year, with a peak incidence at 12 years of age. Metastatic disease is detected in about 20 % to 30% of people, and is typically found in the lungs, bone, bone marrow, or a combination of these. Presence of metastatic disease at diagnosis (primary metastatic disease) is the most important adverse prognostic factor, and is associated with a five-year survival lower than 30%. High-dose chemotherapy (HDC) followed by autologous haematopoietic cell transplantation (AHCT) is used in various solid tumours with unfavourable prognoses in children, adolescents, and young adults. It has also been used as rescue after multifocal radiation of metastases. The hypothesis is that HDC regimens may overcome the resistance to standard multidrug chemotherapy and improve survival rates.

OBJECTIVES

To assess the effects of high-dose chemotherapy with autologous haematopoietic cell transplantation compared with conventional chemotherapy in improving event-free survival, overall survival, quality-adjusted survival, and progression-free survival in children, adolescents, and young adults with primary metastatic Ewing sarcoma, and to determine the toxicity of the treatment.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, conference proceedings from major international cancer-related conferences, and ongoing trial registers until January 2020. We also searched reference lists of included articles and review articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or (historical) controlled clinical trials (CCTs) comparing the effectiveness of HDC and AHCT with conventional chemotherapy for children, adolescents, and young adults (younger than 30 years at the date of diagnostic biopsy) with primary metastatic Ewing sarcoma.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified one RCT, which investigated the effects of HDC with AHCT versus conventional chemotherapy with whole lung irradiation (WLI) in people with Ewing sarcoma metastasised to the lungs only at diagnosis. Only a selection of the participants were eligible for our review (N = 267: HDC with AHCT group N = 134; control group N = 133). There may be no difference in event-free survival between the two treatment groups (hazard ratio (HR) 0.83, 95% confidence interval (CI) 0.59 to 1.17; low-certainty evidence). We downgraded one level each because of study limitations and imprecision. Overall survival and toxicity were not reported separately for the participants eligible for this review, while quality-adjusted survival and progression-free survival were not reported at all. We did not identify any studies that addressed children, adolescents, and young adults with Ewing sarcoma with metastases to other locations.

AUTHORS' CONCLUSIONS

In people with Ewing sarcoma with primary metastases to locations other than the lungs, there is currently no evidence from RCTs or CCTs to determine the efficacy of HDC with AHCT compared to conventional chemotherapy. Based on low-certainty evidence from one study (267 participants), there may be no difference in event-free survival between children, adolescents, and young adults with primary pulmonary metastatic Ewing sarcoma who receive HDC with AHCT and those who receive conventional chemotherapy with WLI. Further high-quality research is needed. Results are anticipated for the EuroEwing 2008R3 study, in which the effects of HDC with treosulfan and melphalan followed by AHCT on survival, in people with Ewing sarcoma with metastatic disease to bone, other sites, or both were explored. Achieving high-quality studies in a selection of people with rare sarcoma requires long-term, multi-centre, international participant inclusion.

Prognostic and therapeutic factors influencing the clinical outcome of metastatic Ewing sarcoma family of tumors: A retrospective report from the Japan Ewing Sarcoma Study Group

BACKGROUND

The prognosis of patients with metastatic Ewing sarcoma family of tumors (ESFT) remains poor.

PROCEDURE

We retrospectively analyzed 57 patients diagnosed with metastatic ESFT between 2000 and 2018 to identify prognostic and therapeutic factors affecting the clinical outcome.

RESULTS

The 3-year overall survival (OS) rate of the entire cohort was 46.8% (95% confidence interval [CI], 33.0-59.4%). Treatment-related death was not observed. Multivariate analysis identified stem cell transplantation (SCT), response to first-line chemotherapy, and bone metastasis as independent risk factors for OS. Objective response rate to first-line chemotherapy was 65.1% in the 43 evaluable patients. There was no significant difference in the response to different types of first-line chemotherapy. Among patients with lung metastasis alone, the 3-year OS rate was higher in 13 patients who received local treatment than in four who did not, although the difference was not significant.

CONCLUSIONS

One possible reason for the high OS rates was the absence of treatment-related mortality even in patients receiving SCT, which could be attributed to advances in the management of post-SCT complications. Novel first-line chemotherapy strategies need to be established to improve the disease status prior to SCT in a higher proportion of patients.

Long-Term Follow-up of High-Dose Chemotherapy with Autologous Stem Cell Transplantation in Children and Young Adults with Metastatic or Relapsed Ewing Sarcoma: A Single-Institution Experience

Forty-seven patients with metastatic disease at diagnosis or recurrent Ewing sarcoma (EWS) received high-dose chemotherapy (HDC) followed by tandem (n = 20, from February 13, 1997, to October 24, 2002) or single (n = 27, from October 1, 2004, to September 5, 2018) autologous hematopoietic stem cell transplantation (ASCT). To our knowledge, this is the largest single-institution study with sustained long-term follow-up exceeding 10 years. All patients who underwent single ASCT received a novel conditioning regimen with busulfan, melphalan, and topotecan. The overall survival (OS) and disease-free survival (DFS) were 46% and 37% at 10 years and 42% and 37% at 15 years, respectively. Disease status at transplant and the time to disease relapse prior to ASCT were identified as important prognostic factors in OS, DFS, and risk of relapse. At 10 years, patients who underwent transplantation in first complete response (1CR) had an excellent outcome (OS 78%), patients in 1CR/second complete response (2CR)/first partial response (1PR) had an OS of 66%, and patients at third or more complete response, second or more partial response, or advanced disease had an OS of 26%. Ten-year OS for patients without a history of relapse, with late relapse (≥2 years from diagnosis), or with early relapse (<2 years from diagnosis) was 75%, 50%, and 18%, respectively. Selected patients in 1CR, 2CR, 1PR, and with late relapse had excellent, sustained 10- and 15-year OS and DFS.

Role of High-Dose Chemotherapy and Autologous Hematopoietic Cell Transplantation for Children and Young Adults with Relapsed Ewing's Sarcoma: A Systematic Review

Background

Relapsed Ewing's sarcoma (RES) is an aggressive malignancy with poor survival. Although high-dose chemotherapy (HDCT) with autologous stem cell transplantation (ASCT) given after conventional chemotherapy (CC) has shown survival benefits, it is not generally used in the United States for RES. We performed a systemic review to evaluate the benefits of HDCT for RES.

Methods

Literature search involved Medline, Embase, and Cochrane database. We included studies with RES patients treated with HDCT/ASCT.

Results

Twenty-four studies with total of 345 reported RES patients that got HDCT were included in final analysis. Seventeen studies had patients with multiple malignancies including RES, while seven had only RES patients. At 2 and 3–5 years, event-free survival (EFS) in studies with only RES patients ranged 42–47% and 20–61% and overall survival (OS) ranged 50–66% and 33–77%, respectively. In studies with combined patients that reported outcomes of RES separately, the EFS at 1–3 and 4 years was 36–66% and 17–50%, respectively. The OS at 1-2 and 3-4 years was 40–60% and 50–70%.

Conclusions

Most studies using HDCT/ASCT as consolidation regimen showed improved survival benefits compared to CC. Randomized controlled studies are needed to determine true clinical benefits of HDCT followed by ASCT in patients with RES.

Bone marrow involvement identifies a subgroup of advanced Ewing sarcoma patients with fatal outcome irrespective of therapy in contrast to curable patients with multiple bone metastases but unaffected marrow

Purpose

Advanced Ewing sarcomas have poor prognosis. They are defined by early relapse (<24 months after diagnosis) and/or by metastasis to multiple bones or bone marrow (BM). We analyzed risk factors, toxicity and survival in advanced Ewing sarcoma patients treated with the MetaEICESS vs. EICESS92 protocols.

Design

Of 44 patients, 18 patients were enrolled into two subsequent MetaEICESS protocols between 1992 and 2014, and compared to outcomes of 26 advanced Ewing sarcoma patients treated with EICESS 1992 between 1992 and 1996. MetaEICESS 1992 consisted of induction chemotherapy, whole body imaging directed radiotherapy to the primary tumor and metastases, tandem high-dose chemotherapy and autologous rescue. In MetaEICESS 2007 this treatment was complemented by allogeneic stem cell transplantation. EICESS 1992 comprised induction chemotherapy, local therapy to the primary tumor only followed by consolidation chemotherapy.

Results

In MetaEICESS 8/18 patients survived in complete remission vs. 2/26 in EICESS 1992 (p<0.05). Survival did not differ between MetaEICESS 2007 and MetaEICESS 1992. Three MetaEICESS patients died of complications, all in MetaEICESS 1992. After exclusion of patients succumbing to treatment related complications (n=3), 7/10 patients survived without BM involvement, in contrast to 0/5 patients with BM involvement. This was confirmed in a multivariate analysis. There was no correlation between BM involvement and the number of metastases at diagnosis.

Conclusion

The MetaEICESS protocols yield long-term disease-free survival in patients with advanced Ewing sarcoma. Allogeneic stem cell transplantation was not associated with increased death of complications. Bone marrow involvement is a risk factor distinct from multiple bone metastases.

Multimodality treatment of intradural extramedullary Ewing's sarcomas. A systematic review

Ewing's sarcoma (ES) is an aggressive bone and soft tissue sarcoma that usually affects adolescents and young adults. ES occasionally presents as an intradural-extramedullary lesion of the spine. Our aim was to study the role of the multimodality treatment on the survival (overall survival, recurrence-free survival, and metastasis-free survival) of patients with intradural-extramedullary Ewing's sarcoma. Pubmed, EMBASE, Scopus, Web of Science, Cochrane Reviews were searched up to January 2017, using as mesh terms "intradural extramedullary", "Ewing's sarcoma", AND "treatment". The multidisciplinary treatment was recorded in binary variables under the headings of "surgery", "chemotherapy" and "radiotherapy". We also recorded three time-to-event variables, including death, recurrence, and metastasis. We performed survival analysis for all potential combinations. Twenty articles with twenty-three patients were eligible for the current review. The survival curves of GTR did not differ from the equivalent of STR regarding survival (p=0.098), recurrence-free survival (p=0.318), and metastasis-free survival (p=0.089). Patients who received chemotherapy enjoyed longer survival regarding overall survival (p<0.05), recurrence-free survival (p<0.05), and metastasis-free survival (p<0.05), when compared to those who did not receive chemotherapy. Their overall survival of patients who had radiotherapy was marginally superior to those who did not receive (p=0.0653). However, their recurrence-free survival (p<0.05), and metastasis-free survival (p<0.05) were significantly improved in comparison to the latter. In conclusion, the multimodality treatment is mandatory for the management of patients with intradural extramedullary Ewing's sarcomas, with surgery assisting in the diagnosis and decompression the neural elements. However, it is chemotherapy that improves survival, recurrence-free survival, and metastasis-free survival. Radiotherapy is reserved as an adjuvant therapy in the local control, especially in cases with subtotal tumour resection.

High-Dose Chemotherapy and Autologous Stem Cell Transplantation in Children with High-Risk or Recurrent Bone and Soft Tissue Sarcomas

Despite increasing evidence that high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) might improve the survival of patients with high-risk or recurrent solid tumors, therapy effectiveness for bone and soft tissue sarcoma treatment remains unclear. This study retrospectively investigated the feasibility and effectiveness of HDCT/auto-SCT for high-risk or recurrent bone and soft tissue sarcoma. A total of 28 patients (18 high-risk and 10 recurrent) underwent single or tandem HDCT/auto-SCT between October 2004 and September 2014. During follow-up of a median 15.3 months, 18 patients exhibited disease progression and 2 died of treatment-related toxicities (1 veno-occlusive disease and 1 sepsis). Overall, 8 patients remained alive and progression-free. The 3-year overall survival (OS) and event-free survival (EFS) rates for all 28 patients were 28.7% and 26.3%, respectively. In the subgroup analysis, OS and EFS rates were higher in patients with complete or partial remission prior to HDCT/auto-SCT than in those with worse responses (OS, 39.1% vs. 0.0%, P = 0.002; EFS, 36.8% vs. 0.0%, P < 0.001). Therefore, careful selection of patients who can benefit from HDCT/auto-SCT and maximal effort to reduce tumor burden prior to treatment will be important to achieve favorable outcomes in patients with high-risk or recurrent bone and soft tissue sarcomas.

High-dose chemotherapy and autologous peripheral blood stem cell transplantation in the treatment of children and adolescents with Ewing sarcoma family of tumors

Purpose

We performed a pilot study to determine the benefit of high-dose chemotherapy and autologous peripheral blood stem cell transplantation (HDCT/autoPBSCT) for patients with Ewing sarcoma family of tumors.

Methods

We retrospectively analyzed the data of patients who received HDCT/autoPBSCT at Korea Cancer Center Hospital. Patients with relapsed, metastatic, or centrally located tumors were eligible for the study.

Results

A total of 9 patients (3 male, 6 female), with a median age at HDCT/autoPBSCT of 13.4 years (range, 7.1 to 28.2 years), were included in this study. Patients underwent conventional chemotherapy and local control either by surgery or radiation therapy, and had achieved complete response (CR, n=7), partial response (n=1), or stable disease (n=1) prior to HDCT/autoPBSCT. There was no transplant-related mortality. However, the median duration of overall survival and event-free survival after HDCT/autoPBSCT were 13.3 months (range, 5.3 to 44.5 months) and 6.2 months (range, 2.1 to 44.5 months), respectively. At present, 4 patients are alive and 5 patients who experienced adverse events (2 metastasis, 2 local recur, and 1 progressive disease) survived for a median time of 2.8 months (range, 0.1 to 10.7 months). The 2-year survival after HDCT/autoPBSCT was 44.4%±16.6% and disease status at the time of HDCT/autoPBSCT tended to influence survival (57.1%±18.7% of cases with CR vs. 0% of cases with non-CR, P=0.07).

Conclusion

Disease status at HDCT/autoPBSCT tended to influence survival. Further studies are necessary to define the role of HDCT/autoPBSCT and to identify subgroup of patients who might benefit from this investigational treatment.

Efficacy of carbon-ion radiotherapy and high-dose chemotherapy for patients with unresectable Ewing's sarcoma family of tumors

BACKGROUND

Treatment for unresectable Ewing's sarcoma family of tumors (ESFT) is a formidable challenge because of its high tendency for local and distant failure. Recently, carbon-ion radiotherapy (CIRT) has been applied to unresectable bone and soft tissue sarcoma. Additionally, high-dose chemotherapy (HDC) with stem cell rescue has been used to improve the survival of patients with relapsed ESFT. Here we report our experience with CIRT and HDC in the treatment of unresectable ESFT.

METHODS

Five unresectable ESFT patients including 4 who underwent CIRT and HDC and one who underwent CIRT from 1999-2009 were retrospectively studied. After neoadjuvant chemotherapy, CIRT was conducted at the National Institute of Radiological Sciences in Chiba as local therapy. Consecutively, we employed HDC including busulfan, melphalan, and thiotepa with stem cell rescue.

RESULTS

Two patients showed tumor shrinkage after CIRT, including 1 patient who achieved partial response. No severe acute toxicity related to CIRT was observed. Local failure was observed in only 1 patient at 22 months after CIRT. Four patients conducted HDC with stem cell rescue after CIRT and 1 patient suffered from veno-occlusive disease just after HDC. Distant failure was observed in 3 patients after completion of the treatment.

CONCLUSIONS

CIRT and HDC for unresectable ESFT patients show favorable local control, with unsatisfactory results for distant control.

Comprehensive analysis of published phase I/II clinical trials between 1990-2010 in osteosarcoma and Ewing sarcoma confirms limited outcomes and need for translational investment

Background

High grade primary bone sarcomas are rare cancers that affect mostly children and young adults. Osteosarcoma and Ewing sarcoma are the most common histological subtypes in this age group, with current multimodality treatment strategies achieving 55-70% overall survival. As there remains an urgent need to develop new therapeutic interventions, we have reviewed published phase I/II trials that have been reported for osteosarcoma and Ewing sarcoma in the last twenty years.

Results

We conducted a literature search for clinical trials between 1990 and 2010, either for trials enrolling bone sarcoma patients as part of a general sarcoma indication or trials specifically in osteosarcoma and Ewing sarcoma. We identified 42 clinical trials that fulfilled our search criteria for general sarcoma that enrolled these patient groups, and eight and twenty specific trials for Ewing and osteosarcoma patients, respectively. For the phase I trials which enrolled different tumour types our results were incomplete, because the sarcoma patients were not mentioned in the PubMed abstract. A total of 3,736 sarcoma patients were included in these trials over this period, 1,114 for osteosarcoma and 1,263 for Ewing sarcoma. As a proportion of the worldwide disease burden over this period, these numbers reflect a very small percentage of the potential patient recruitment, approximately 0.6% for Ewing sarcoma and 0.2% for osteosarcoma. However, these data show an increase in recent activity overall and suggest there is still much room for improvement in the current trial development structures.

Conclusion

Lack of resources and commercial investment will inevitably limit opportunity to develop sufficiently rapid improvements in clinical outcomes. International collaboration exists in many well founded co-operative groups for phase III trials, but progress may be more effective if there were also more investment of molecular and translational research into disease focused phase I/II clinical trials. Examples of new models for early translational and early phase trial collaboration include the European based EuroBoNeT network, the Sarcoma Alliance for Research through Collaboration network (SARC) and the new European collaborative translational trial network, EuroSarc.

High-dose chemotherapy and stem cell rescue for high-risk Ewing's family of tumors

The prognosis for high-risk Ewing's tumors has been improved by multimodal radiation and chemotherapy. Ewing's family of tumors requires risk-adapted treatment. Risk stratification is dependent on stage, tumor localization and volume, and the pattern of disease spread at the time of diagnosis and the time of relapse. The concepts for high-dose therapy followed by hematopoietic cell transplantation in Ewing's family of tumors are based on dose-response and dose-intensity relationships. This article will discuss the use of high-dose therapy followed by hematopoietic cell transplantation, focusing on recent progress with respect to agent combinations, dose and outcomes of therapy.

High-dose chemotherapy for children and young adults with stage IV rhabdomyosarcoma

BACKGROUND

Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood. Prognosis for patients with metastatic disease has not improved significantly in the past decades. High-dose chemotherapy (HDC) seems to be an attractive option to treat minimal residual disease in metastatic rhabdomyosarcoma patients.

OBJECTIVES

The objective of the review was to assess the effectiveness of HDC with stem cell rescue (SRC) versus standard-dose chemotherapy in improving event-free survival (EFS) and overall survival (OS) of children and young adults with metastatic rhabdomyosarcoma.

SEARCH STRATEGY

We searched the databases of MEDLINE (1966 to December 2009), EMBASE (1980 to December 2009) and CENTRAL (The Cochrane Library Issue 1, 2009). In addition, we handsearched the reference lists of selected papers and conference proceedings of the SIOP, ASPHO and ASCO meetings (all 2000 to 2009).

SELECTION CRITERIA

Randomised controlled trials (RCT), prospective or historical controlled clinical trials (CCT), in which HDC with SCR was compared to conventional chemotherapy and prospective case series (non-controlled clinical trials) including at least 20 naive metastatic rhabdomyosarcoma patients

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, quality assessment and data extraction.

MAIN RESULTS

No RCTs could be identified. We identified one prospective CCT, one retrospective CCT and one non-controlled clinical trial. Another CCT has been published as an abstract. All studies have severe methodological limitations, in particular selection bias could not be excluded. One CCT reported a significantly worse OS compared to oral maintenance therapy, however in a subgroup of high-risk patients no difference could be found. The retrospective CCT reported a similar survival for HDC compared to conventional chemotherapy. The non-controlled clinical trial and the CCT reported as a conference proceeding reported survival outcomes comparable to previous studies. Data on toxicity showed more grade 3-4 toxicity in the HDC group. However, there was no difference in the number of toxic deaths.

AUTHORS' CONCLUSIONS

Overall, the results of this review do not justify the use of HDC with SCR as a standard therapy for children with metastatic rhabdomyosarcoma. However, all reported studies were possibly subject to significant bias, especially selection bias. This might have underestimated the measured effect of HDC. As a result, a clinically important excess of adverse risk patients in the HDC arms may explain the non-beneficial effect of HDC. Only a large prospective RCT will be able to answer the question of whether HDC with SCR adds to survival or not definitively.

The value of local treatment in patients with primary, disseminated, multifocal Ewing sarcoma (PDMES)

BACKGROUND

The value of local treatment in patients with primary, disseminated, multifocal Ewing sarcoma (PDMES) was investigated.

METHODS

We analyzed 120 patients registered into the European Ewing Tumor Working Initiative of National Groups (EURO-E.W.I.N.G. 99) trial at the trial center of Muenster from 1998 to 2006. Median age was 16.2 years. Local treatment of the primary tumor was surgery in 26 of 120 patients, surgery and radiotherapy in 21 patients, and definitive radiotherapy in 40 patients. For treatment of metastases, 6 of 120 patients received surgery; 9 patients, surgery and radiotherapy; and 33 patients, definitive radiotherapy. Forty-seven (39%) patients had local treatment of both the primary tumor and metastases, 41 (34%) patients of either the primary tumor or metastases, and 32 (27%) received no local therapy.

RESULTS

Event-free survival (EFS) at 3 years was 0.24 (95% CI, 0.16-0.33). Univariate analyses demonstrated the impact of local therapy given to the primary tumor: 3-year EFS was 0.25 with surgery, 0.47 with surgery and radiotherapy, 0.23 with radiotherapy, and 0.13 when no local therapy was administered (P < .001). Three-year EFS in PDMES was also influenced by the local treatment: surgery, 0.33; surgery and radiotherapy, 0.56; radiotherapy, 0.35; no local therapy, 0.16 (P = .003). Three-year EFS was 0.39 in patients who received local treatment of both primary tumor and PDMES, compared with 0.17 in patients with any local treatment of either primary tumor or PDMES and 0.14 in patients with no local therapy (P < .001). Multivariate analysis showed absence of local treatment to be the major risk factor (HR = 2.21; P = .027; n = 20).

CONCLUSIONS

Local therapy of involved sites is important for patients with PDMES and should complement systemic treatment whenever possible.