Ewing's sarcoma: a trial of adjuvant chemotherapy and sequential half-body irradiation

Does consolidation with autologous stem cell transplantation improve the outcome of children with metastatic or relapsed Ewing sarcoma?

OBJECTIVE

To evaluate the role of high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT) as consolidation therapy for children with high-risk Ewing sarcoma (ES) treated at The Hospital for Sick Children (SickKids), Toronto.

PATIENTS AND METHODS

The charts of children treated for high-risk ES (defined as metastatic at diagnosis or relapsed) between 1990 and 2005 at SickKids were reviewed. Forty-five children were identified. Twenty patients received ASCT after induction with vincristine, doxorubicin, ifosfamide, cyclophosphamide, and etoposide. Patients with resectable tumor or lung metastases underwent surgery and those with non-resectable tumors were treated with irradiation. Twenty-five patients were treated with conventional chemotherapy (CC). Primary metastatic patients were treated with either a local protocol or as per POG 9354. At relapse, patients were treated with topotecan, cyclophosphamide, then ifosfamide, carboplatin, and etoposide (ICE). Local control was attained with surgery and/or irradiation.

RESULTS

Ten of the 20 patients treated with ASCT are alive (median follow-up 6 years), with 8/10 being in remission more than 5 years from diagnosis. The 3-year overall survival (OS) for ASCT was 59%, (95% CI: 36%, 81%) compared to 34% (14%, 53%) for patients treated with CC (P-value = 0.06). The 3-year event-free survival (EFS) for the ASCT was 39% (17%, 60%) compared to 32% (13%, 50%) in the CC group (P = 0.08).

CONCLUSION

ASCT appears to add some benefit to conventional multimodality therapy for children with high-risk ES. Randomized controlled trials are warranted.

High-dose chemoradiotherapy (HDC) in the Ewing family of tumors (EFT)

EFT is defined by the expression of ews/ets fusion genes. The type of the fusion transcript impacts on the clinical biology. EFT requires risk adapted treatment. A risk-adapted treatment is determined by tumor localisation, tumor stage and volume. For metastatic and relapsed disease the pattern of spread and the time of relapse are the determinants of risk stratification. Staging of Ewing tumors has been considerably improved by magnetic resonance imaging and modern isotope scanning techniques. However, the determination of the extent of the metastatic spread in particular number of involved bones remains an unresolved issue. The prognosis for high-risk Ewing tumors has been improved by multimodal and high-dose radio/chemotherapy (HDC). The concepts for high-dose therapy in Ewing tumors are based on dose response and dose intensity relationships. In single agent HDC most experience exists with Melphalan. Several chemotherapeutic agents have been used in combination HDC with or without TBI such as Adriamycin, BCNU, Busulphan, Carboplatin, Cyclophosphamide, Etoposide, Melphalan, Thiotepa Procarbazin and Vincristine. To date, superiority of any high-dose chemotherapy regimen has not been established. However, the clinical biology, the pattern of spread and the time of relapse determine the prognosis of patient who are eligible for HDC. In particular, patients with multifocal bone or bone marrow metastases have a poorer prognosis than patients with lung metastases. In addition, patients with a relapse within 24 months have a poorer prognosis than patients with a relapse later than 24 months after diagnosis. This review will analyze the results of single- and multi-agent chemotherapy with respect to agent combination, dose and risk stratum of patient population. Future therapeutic modalities for the treatment of EFT might encompass immunotherapeutic and genetic strategies including allogeneic stem cell transplantation.

Long-term outcome of patients with monostotic Ewing's sarcoma treated with combined modality

One hundred and twenty-one consecutive patients with monostotic Ewing's sarcoma (ES) were treated according to three consecutive combined modality programs from 1974 to 1986. Their 3-year progression free survival (PFS) rate from diagnosis of 59% was identical to the event free survival (EFS) rate, since all the 50 events occurring within 3 years from diagnosis were tumor recurrences. Primary tumor was treated with radiotherapy in 75 cases, surgical resection plus radiotherapy in 38, and radical surgery in 8. Chemotherapy was given to all patients and each program included adriamycin, vincristine, and cyclophosphamide +/- dactinomycin. Median follow-up was 12 years, ranging from 6 to 19 years. The PFS rate decreased to 49% at 6 years and plateaued at 46% after the 7th year from diagnosis, even though some relapses were observed as late as 14 years from diagnosis. Second malignancies developed in 7 patients free from progressive ES and were represented by osteogenic sarcoma in previously irradiated bone in 4 cases and by breast carcinoma in 3. No other event but tumor relapse or second malignancy occurred in this series. EFS rate was 47% at 6 years and 39% at 12 years, further decreasing in the following years because of a number of late events. A continuous PFS longer than 7 years may be consistent with cure in the majority of patients with monostotic ES. However, these patients should be followed indefinitely because of risk of second malignancies.

Ewing's sarcoma: long-term follow-up in 49 patients treated from 1967 to 1989

PURPOSE

Review of long-term results of therapy for Ewing's sarcoma in terms of survival, local tumor control, distant failure and complications rates.

METHODS AND MATERIALS

Retrospective review of the records of patients with Ewing's sarcoma of bone and soft tissues treated at The Prince of Wales Children's and Prince of Wales Hospitals, Sydney, between 1967 and 1989 and followed-up to July 1991.

RESULTS

There were 49 patients with median age 16 years (range 3-33 years) and average potential follow-up time 12.3 years (range 2-24 years). Forty patients presented with localized disease (three with regional lymph node involvement) and nine with distant metastases. Local therapy for the primary was by amputation in three patients, by resection and postoperative radiotherapy in five, and by definitive radiotherapy in 41 (median dose 50 Gy). Forty-four patients received adjuvant multi-agent chemotherapy. The overall actuarial survival rate was 33% (SE = 7%) at 5 years and 30% (SE = 7%) at 10, 15, and 20 years. The factors predictive of shorter survival were distant metastases at diagnosis (p = 0.036) and older age (p = 0.025). The actuarial local control rate for all 49 patients was 75% (SE = 8%) at 5, 10, 15, and 20 years. The only factor predictive of local failure was an inadequate target volume irradiated (p = 0.003). In 40 patients who presented with localized disease only, the actuarial rate of freedom from distant failure at 5 years was 44% (SE = 8%) and at 10, 15, and 20 years was 40% (SE = 8%). Seven patients experienced severe or fatal complications (defined as requiring investigation and treatment in hospital), namely stress fracture in two, fatal osteogenic sarcoma in one, fatal cardiotoxicity in one and severe hemorrhagic cystitis in three. The rate for severe or fatal complications at 5 years was 19% (SE = 8%), at 10 years was 29% (SE = 12%) and at 15 and 20 years was 53% (SE = 21%).

CONCLUSION

Survival to 5 years appears to confer probable cure and one third of our patients have achieved this. Long-term follow-up also reveals that an increasing number of patients experience treatment-related complications, the majority of which, however, can be corrected.

Late tissue reactions after single-fraction sequential half-body irradiation (HBI) in patients with non-Hodgkin's lymphomas

Lung and hepatic toxicities constituted the main radiation-related damage after half-body irradiation (HBI) used as the treatment for patients with non-Hodgkin's lymphomas (NHL). Liver damage was mostly transient after a single dose of 8 Gy and could be well monitored by serum enzyme levels. A dose-response relationship could be shown for lung damage in the single dose range of 6.25-9.25 Gy, but the relationship did not reach statistical significance. A significant dose-rate effect could be shown. Mediastinal involvement by lymphoma seemed to increase the risk of pneumonitis. In a radical setting half-body irradiation is recommended to be used at a low dose-rate or as a multifraction irradiation in order to reduce the risk of liver and lung toxicities.

Treatment of pelvic sarcomas in adolescents and young adults with intensive combined modality therapy

Adolescent and young adult patients with pelvic sarcomas continue to have a poor prognosis with standard combination chemotherapy and local irradiation. In addition to a significant risk of local failure, these patients are at high risk for systemic relapse. Twenty-three consecutive patients with Ewing's sarcoma, alveolar rhabdomyosarcoma, undifferentiated sarcoma, or malignant peripheral neuroepithelioma originating in the pelvis were treated with short, intensive combined modality therapy. This approach integrates 5 cycles of VADRIAC chemotherapy (Vincristine, Adriamycin, Cyclophosphamide) with high dose irradiation to the primary lesion (55-60 Gy) and sites of gross metastatic disease (45-50 Gy). Following achievement of a complete response, intensification therapy consisting of total body irradiation (TBI) (8.0 Gy), high dose VADRIAC chemotherapy, and autologous bone marow transplantation is given. All therapy is completed within 6-7 months. No maintenance chemotherapy is given; no surgery is intended. Of the twenty-three patients with pelvic sarcomas treated on this combined modality protocol, 22 achieved a complete remission. Local control was achieved and maintained in all twenty-three patients. With a median follow-up of 21 months since initiation of treatment, there have been nine relapses (all systemic). Seven relapses occurred among the thirteen patients who presented with overt metastatic disease and the other two relapses were among the ten patients with localized disease at presentation. All seven metastatic patients who relapsed have died, whereas both of the relapsed localized patients remain alive. Acute and late toxicities have been acceptable using this aggressive combined modality approach. Induction chemotherapy had a significant impact on reduction of the typically large (greater than 10 cm diameter) soft tissue mass associated with these pelvic tumors, thus facilitating achievement of local control by high dose irradiation. Of 18 patients with measureable soft tissue tumor, all experienced a partial response (greater than 50% reduction in size) following the initial two cycles of chemotherapy given prior to local irradiation. In conclusion, this short, intensive chemoradiotherapeutic regimen is highly effective in controlling the primary lesion (100% local control) and inducing a complete response in a high proportion (96%) of these high risk pediatric and young adult patients with pelvic sarcomas. The role of TBI as "systemic" adjuvant therapy to control micrometastatic disease is discussed as still under investigation.

Advances in pediatric radiotherapy in the last ten years and future proposals

Advances made can be divided into five main categories. Firstly, the problem of geographic miss which has been reduced by delivering effective radiation doses with greater precision. This has been accomplished with more sophisticated diagnostic and therapeutic equipment, immobilization techniques and computerized treatment planning. Second is the recognition of the interplay of radiation and chemotherapy on normal tissue tolerance and local tumor control. This interaction has necessitated reduction in both dose and volume of irradiation. Third is the use of wide field irradiation as a systemic treatment. Fourthly, the utilization of cooperative group trials to define the role of irradiation. Finally, with the improvement in survival has come the recognition of late effects of irradiation in the growing child and the means of reducing such effects. The current role of radiation therapy in childhood malignancies is summarized, controversies are identified, and future prospects explored.