Abstract
Background/Aim: Ewing sarcoma is a common primary bone tumor, often located in the distal femur or pelvis. Although the scapula is a flat bone similar to the pelvis, scapular Ewing sarcoma is rare. The aim of this study was to review our institution’s experience with the management of scapular Ewing sarcomas. Patients and Methods: We reviewed 9 patients with an Ewing sarcoma of the scapula, which included 5 males and 4 females with a mean age of 19±6 years. All patients were treated with chemotherapy and local control. Local control included surgical resection (n=7) and definitive radiotherapy (n=2). Mean follow-up was 6 years. Results: Prior to induction chemotherapy, the mean tumor size and volume were 10±2 cm and 181±112 cm3, respectively. Following induction chemotherapy, there was a reduction in the mean tumor size (6±3, p=0.02) and volume (20±12 cm3, p<0.01). The mean tumor necrosis in patients undergoing resection was 72±23%. The median survival was 30-months, and the 5-year disease specific survival was 38%. At most recent follow-up, the mean Musculoskeletal Tumor Society Score was 79±14%. Conclusion: Scapular Ewing sarcoma is a rare, aggressive tumor. Even with chemotherapy and local control with surgery or definitive radiotherapy, patient survival is poor.
Ewing sarcoma, although rare, remains one of the most common primary sarcomas, accounting for 16% of bone sarcomas, typically impacting children and young adults (1, 2). Ewing sarcoma typically arises from the long bones of the lower extremity and pelvis, however primary Ewing sarcoma of the scapula is rare, accounting for less than 4% of all cases (3).
The scapula is of major importance for upper extremity function. It is the origin or insertion for 17 different muscles, allowing for six major movements including elevation, depression, upward and downward rotation, adduction, and abduction (4). Due to the functional importance of the scapula, any intervention can have profound and lasting effects. Thus, management of scapular Ewing sarcoma is complex. Previous case series examining the outcomes of patients with scapula Ewing sarcoma are limited. Many publications are small or are single patient case studies (5-8). The purpose of the current study was to report our institutional experience with treating patients with scapular Ewing sarcoma.
Patients and Methods
Following institutional review board approval, we reviewed all cases of histologically confirmed scapular Ewing sarcoma treated at our institution in the past 30 years. One patient was removed from the study due to an unknown cause of death shortly after completing six cycles of neoadjuvant chemotherapy before local control. The remaining nine patients (5 males and 4 females) with a mean age of 19±6 years at the time of diagnosis were included in the review (Table I).
Patients with scapular Ewing sarcoma.
Following local control and consolidation chemotherapy, patients were followed every 3-4 months for the first 2-years, every 6-months for years 2-5 and annually for years 5-10. Follow-up included a CT-scan of the chest and local imaging including radiographs and MRI of the chest. Functional outcomes were measured utilizing the Musculoskeletal Tumor Society Score (MSTS93) (9) at the patients most recent follow-up.
Statistical analysis. Descriptive statistics were used where appropriate with data reported as means±standard deviation. Categorical variables were compared utilizing Fisher exact tests and continuous variables were compared utilizing Student t-tests. Statistical significance was set at a p-value <0.05. The Kaplan Meir method was utilized to analyzed survival outcomes.
Results
All patients were treated with chemotherapy, most commonly vincristine, doxorubicin, and cyclophosphamide with additional ifosfamide and etoposide (VDC/IE, n=6). Two patients received vincristine, doxorubicin, and cyclophosphamide with additional dactinomycin in place of ifosfamide and etoposide. One patient received epirubicin as primary chemotherapy treatment.
The mean pre-chemotherapy tumor size was 10±2 cm in the greatest dimension. Mean volume calculated using an elliptical method was 186±124 cm3. Following induction chemotherapy, the mean tumor size and volume reduced to 6±3 cm (p=0.02) and 20±12 cm3 (p<0.01), respectively. This represented a mean reduction in volume of 83±11%.
Local control. Seven patients underwent surgical resection for local control. Four patients underwent partial scapulectomy and three underwent total scapulectomy. The mean tumor size and volume at the time of resection were 8±6 cm, and 325±461 cm3, respectively. The mean tumor necrosis was 72±23%. Margins were negative in six patients, and microscopically positive in one.
Definitive radiotherapy was utilized in two cases with a total dose of 55.8 Gy given in 31 fractions. Patients chose to undergo radiotherapy as a means for local control due to the perceived functional impact of surgical resection.
Survival. Following local control, the median survival among all patients was 30-months, with a 5-year disease specific survival of 38%. It should be noted that three patients primarily presented with metastatic pulmonary disease, which was treated with radiotherapy following consolidation chemotherapy. One of these patients developed widely metastatic bone disease and further pulmonary disease.
Of the six patients without metastasis at primary presentation, four developed metastatic disease. Sites of metastatic disease included the lungs (n=4), bone (n=2) and soft tissue (n=1). Patients who presented with metastatic disease were not included in the metastatic free survival. For the remaining patients, the 5-year metastatic free survival was 33%. Local recurrence occurred in 2 patients. One of the patients was initially treated with definitive radiotherapy and had local tumor progression at 13-months. The other patient was initially treated with surgery and had a positive margin and developed local recurrence at 3 months. This patient also developed rapid metastatic disease and treatment for the recurrence was not undertaken.
Functional outcomes and complications. Following local control, the mean MSTS93 score was 79±14% and the mean shoulder elevation and external rotation reported were 63±70° and 17±22°, respectively. One patient in the surgical group had a postoperative wound complication. This delayed adjuvant chemotherapy treatments until the wound healed.
Discussion
Ewing sarcoma is the second most common primary bone malignancy in children and young adults. Due to the functional necessity of the scapula for the upper limb, management of Ewing sarcoma of the scapula is difficult. Our study found that neoadjuvant chemotherapy has an impact on the primary tumor size, and that surgery lead to limb salvage in all cases. Unfortunately, survival remains poor even with multimodal approaches to care.
With combined chemotherapy and local control, survival in patients with Ewing sarcoma has continued to improve (10, 11). Prior to the use of cytotoxic chemotherapy survival was 10%, however, survival has improved to over 85% (11, 12). Not only does chemotherapy treat the micrometastatic disease that is not recognized at the time of induction chemotherapy, but it also assists with surgical resectability by leading to a reduction in the tumor size and volume (13-16). This was also observed in our study, as the mean tumor size and volume of the tumor shrunk from 10±2 cm to 6±3 cm (p=0.02), leading to a mean reduction in total volume of 83±11% (p<0.01).
In the current study 1/3 of patients presented with metastatic disease, which is similar to previous studies (17). Compared to patients with non-metastatic Ewing sarcoma, metastatic disease is associated with poor survival (10, 12, 18, 19). Of the seven patients with evidence of metastasis during their disease course, only one remains alive today (14%). The metastatic disease in this patient was treated with radiotherapy, which has been shown to be effective in these situations (20, 21). Our data, although limited, supports the prognostic impact of metastatic disease on long-term survival.
Although the sample size is small, the use of neoadjuvant chemotherapy appears to play a role in primary tumor size reduction in Ewing sarcoma of the scapula. It is worth noting that percent necrosis in our study did not have a prognostic value as has been found in other studies (22-24). Of those that are alive today, percent necrosis was a mean of 75%, whereas in those who died of disease the percent necrosis was 68% (p=0.74). This effect may impact success of local resection and be of prognostic value in evaluating treatment response. It is known that metastasis is the most important prognostic factor impacting patient survival with Ewing sarcomas (12, 25). Thus, treatment initiation early in the disease course with a multimodal approach before metastasis emerges may have the most impact on long-term outcomes.
The most significant limitation to our study is the sample size, which limits definitive conclusions from our observations. Further, our study expands across three decades. As surgical approaches and knowledge of chemotherapy and radiation have changed over that same period. The study is limited to a single center, as such the generalizability of this study could be limited, in addition radiotherapy and surgery were used for local control, and there was no randomization in the choice of local control.
Overall scapular Ewing sarcomas are rare, aggressive tumors. Following induction chemotherapy, there is a statistically significant reduction in the size of the primary tumor. Limb salvage was achievable in all cases with local surgical resection. However, even with chemotherapy and local control with surgery or definitive radiotherapy, patient survival is poor. Much is yet to be discovered in regard to Ewing sarcoma of the scapula and the correct management of this disease.
Footnotes
Authors’ Contributions
Hargiss: Drafting of initial and final manuscript, data collection, data analysis; Labott: Review and editing of final manuscript; Broida: Review and editing of final manuscript; Rose: Review and editing of final manuscript; Barlow: Review and editing of final manuscript; Houdek: Drafting of initial and final manuscript, data analysis, supervision.
Conflicts of Interest
The Authors have no conflicts of interest to declare regarding this study.
- Received June 19, 2022.
- Revision received June 28, 2022.
- Accepted June 30, 2022.
- Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.
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