Local Control Modality and Outcome for Ewing Sarcoma of the Femur: A Report From the Children's Oncology Group

The Outcome of Children With Malignant Bone Tumors: A Single-Center Experience

Malignant bone tumors (MBT) account for 3% to 5% of cancers in children younger than 15 years. We aimed to report the outcome of children with MBT in 10 years in Southern Iran. During the study period, 100 patients (57 Osteosarcoma, 43 Ewing sarcoma) with an M/F ratio of 1.56 and a median age of 13.8 years (3.8-17.9) were diagnosed. Metastasis occurred in 27% of patients, mostly in the first 3 months of diagnosis. The mean survival time of MBT altogether was 94.1 months (95% CI: 86.5-101.7). The 5-year overall survival and event-free survivals were 85.2% (95% CI: 74%-91.8%) and 69.2% (95% CI: 56%-79%), respectively. Metastasis was the only independent risk factor of death in our study cohort (Hazard ratio 36.7, 95% CI: 4.8-282.6, P = .001) MBT in children mostly occur in adolescent boys. About one-third of them become metastatic, which is significantly associated with poor outcomes.

Predictors of Recurrence and Patterns of Initial Failure in Localized Ewing Sarcoma: A Contemporary 20-Year Experience

BACKGROUND

The majority of patients with localized Ewing sarcoma will remain disease-free long term, but for those who suffer recurrence, successful treatment remains a challenge. Identification of clinicopathologic factors predictive of recurrence could suggest areas for treatment optimization. We sought to describe our experience regarding predictors of recurrence and patterns of first failure in patients receiving modern systemic therapy for nonmetastatic Ewing sarcoma.

METHODS

The medical records of pediatric and adult patients treated for localized Ewing sarcoma between 1999 and 2019 at Johns Hopkins Hospital were retrospectively analyzed. Local control was surgery, radiotherapy, or both. Recurrence-free survival (RFS) was calculated using the Kaplan-Meier method. Univariable and multivariable Cox proportional-hazards modeling was performed to obtain hazard ratios (HR) for recurrence.

RESULTS

In 94 patients with initially localized disease, there were 21 recurrences: 4 local, 14 distant, and 3 combined. 5-year and 10-year RFS were 75.6% and 70.5%, respectively. On multivariable analysis including age at diagnosis and tumor size, <95% tumor necrosis following neoadjuvant chemotherapy (NAC; HR 14.3, p = 0.028) and radiological tumor size change during NAC (HR 1.04 per 1% decrease in size change, p = 0.032) were independent predictors of recurrence. Among patients experiencing distant recurrence, pulmonary metastases were present in 82% and were the only identifiable site of disease in 53%.

CONCLUSIONS

Poor pathologic or radiologic response to NAC is predictive of recurrence in patients with localized Ewing sarcoma. Suboptimal tumor size reduction following chemotherapy provides a means to risk-stratify patients who do not undergo definitive resection. Isolated pulmonary recurrence was a common event.

Seeking international consensus on approaches to primary tumour treatment in Ewing sarcoma

BACKGROUND

The local treatment of Ewing sarcoma of bone involves surgery, radiotherapy or both. The selection of treatment depends on the anatomical extent of the tumour, the effectiveness of the proposed treatment, its morbidity, and the expectation of cure. However, not only are there variations in the approach to local treatment between individual patients, but also between treatment centres and countries. Our aim was to explore variation in practice and develop consensus statements about local treatment.

METHODS

A three stage modified Delphi technique was used with international collaborators. This involved an expert panel to identify areas of controversy, an online survey of international collaborators and a consensus meeting in London, UK in June 2017. In the consensus meeting, teams of clinicians discussed the local management of selected cases and their responses were collected with electronic voting.

RESULTS

Areas of greater or less consensus were identified. The lack of evidence underpinning different approaches was noted and areas for collaborative research became apparent.

CONCLUSION

This has demonstrated that there is an international consensus around many aspects of the local treatment of Ewing sarcoma of bone, including the use of specialist MultiDisciplinary Team (MDT) meetings with access to all appropriate treatments. However, considerable variation remains including the use of different staging investigations, decision making, definitions of response, and radiotherapy doses and timing. Further collaborative work should be undertaken to determine the impact of these variations in order to define best practice.

The impact of local control timing in Ewing sarcoma

AIM

To assess the impact of delay in local control on survival outcomes of Ewing sarcoma (ES) patients.

BACKGROUND

The cornerstone of therapy of localized ES includes chemotherapy and local control with surgery or radiotherapy. We sought to assess the impact of delay (>15 weeks) in timing of local control on survival outcomes of ES patients.

METHODS

Data of consecutive patients with primary non-metastatic ES of the extremities, treated at a single institution were collected. The impact of delay of timing for local control, demographics, and disease characteristics on overall survival (OS) was analyzed.

RESULTS

A total of 43 patients with ES of the extremity were included. All patients received neoadjuvant chemotherapy. Local control was by surgery in 36 patients and definitive radiation in 7. A total of 16 patients had delay in local control. At a median follow of up of 48 months, patients with delay in local control had significantly inferior OS compared to those with optimal local control timing (5-year OS 56% vs. 80%, respectively, p = 0.044). Other factors that predicted inferior OS included definitive radiation as opposed to definitive surgery (5-year OS 25% vs. 79%, respectively, p = 0.041) and tumor necrosis <90% as opposed to ≥90% (5-year OS 55% vs. 90%, respectively, p = 0.01).

CONCLUSION

Delay in definitive therapy, local control with radiation as opposed to surgery and poor post-chemotherapy tumor necrosis predict inferior OS in ES. Adopting strategies to minimize delay in local control could improve survival outcomes.

The adrenergic receptor antagonists propranolol and carvedilol decrease bone sarcoma cell viability and sustained carvedilol reduces clonogenic survival and increases radiosensitivity in canine osteosarcoma cells

Adrenergic receptor (AR) expression has been demonstrated at several sites of primary and metastatic tumour growth and may influence proliferation, survival, metastasis and angiogenesis. AR antagonists like propranolol and carvedilol inhibit proliferation, induce apoptosis and synergize with chemotherapy agents in some cancers. Radiation resistance is mediated in many cells by upregulation of pro-survival pathways, which may be influenced by ARs. Studies evaluating AR antagonists combined with radiation are limited. The purpose of this study was to determine the effect of propranolol and carvedilol on viability and radiosensitivity in sarcoma cell lines. The hypothesis was that propranolol and carvedilol would increase radiosensitivity in four primary bone sarcoma cell lines. Single agent propranolol or carvedilol inhibited cell viability in all cell lines in a concentration-dependent manner. The mean inhibitory concentrations (IC₅₀ ) for carvedilol were approximately 4-fold lower than propranolol and may be clinically relevant in vivo. Immunoblot analysis confirmed AR expression in both human and canine sarcoma cell lines; however, there was no correlation between baseline AR protein expression and radiosensitivity. Short duration treatment with carvedilol and propranolol did not significantly affect clonogenic survival. Prolonged exposure to propranolol and carvedilol significantly decreased the surviving fraction of canine osteosarcoma cells after 3Gy radiation. Based on our results and possible in vivo activity in dogs, further studies investigating the effects of carvedilol on sarcoma are warranted.