Abstract
Background/Aim: Scapular osteosarcoma is a rare malignancy, and the understanding of its optimal treatment strategies and long-term outcomes remains limited. The purpose of the current study was to evaluate our institutional experience. Patients and Methods: We reviewed 14 patients (8 females, 5 males; mean age 44±17 years) treated for scapular osteosarcoma from 1985 to 2022. Tumors were confirmed histologically and treated with a multidisciplinary approach, including chemotherapy and surgery with a median follow-up of 10 years. Results: Surgical complications occurred in eight patients, leading to repeat procedures in four. Complications were associated with the use of implants or allografts (p<0.01). Mean shoulder forward elevation and external rotation at follow-up were 42±61° and 12±16°, with a mean MSTS93 score of 61±19%. The 10-year disease-specific survival rates was 76%. Local recurrence was associated with worse survival (HR=13.19, p=0.04). Conclusion: Scapular osteosarcoma is rare, and with multidisciplinary management, local control is essential to patient survival.
Osteosarcoma is the most common primary malignant bone tumor that primarily affects long bones, such as the femur and tibia (1, 2). Osteosarcoma originating in the scapula is rare (3-6) and presents unique surgical and reconstructive challenges due to the complex anatomy of the shoulder girdle (7).
Historically, forequarter amputation was the surgical approach for scapular osteosarcoma (8, 9). However, advancements in medical management and surgical techniques have allowed for limb salvage techniques to become the primary means of surgical resection (8-13). Despite the challenges in achieving negative surgical margins due to the scapula’s proximity to vital structures, modern techniques allow for reconstruction of bone defects, improving both oncologic and functional outcomes (14, 15).
Patients and Methods
Following institutional review board approval, we retrospectively reviewed 14 (8 females and 6 males, mean age 44±17 years) patients who underwent surgical treatment for scapular osteosarcoma from 1985 and 2022 (Table I).
Patients and outcomes with scapular osteosarcoma.
All tumors were histologically confirmed to arise from the bony scapula by preoperative imaging and on the resected tumor specimen. The group included 11 (79%) patients with high grade tumors, with the most common histological subtype being osteoblastic osteosarcoma (n=5, 36%). Eleven (79%) patients received chemotherapy. The chemotherapy regimens have changed over time, with our current practice being a combination of doxorubicin and cisplatin, with or without methotrexate based on patient age and comorbidities (n=5). Chemotherapy is not routinely used for low-grade tumors. In the patients who received neoadjuvant chemotherapy (n=10), the mean tumor necrosis was 61±41%.
All patients underwent wide-local excision with a limb-salvage procedure. All margins were negative at the time of resection with a mean tumor free distance of 10±9 mm. Tumor location was based on a combination of the methods described by Enneking et al. (16) and Malawer (17), most commonly 1A (n=4) and 1234B (n=4), and Type 2 (n=5). The group included nine (64%) patients undergoing a total scapular resection, with five (35%) patients undergoing a partial scapular resection. Five (35%) resections included the humerus and five (35%) included a resection of the axillary nerve. On the resected specimen the median tumor size was 8±4 cm with 12 (86%) patients having a soft-tissue mass associated with their tumor. Reconstruction was individualized based on the extent of resection including prosthetic spacer endoprosthesis (n=4), suspension of the native humerus (n=3), no formal reconstruction (n=3), allograft scapula (n=2), allograft scapula with reverse total shoulder (n=1), and resection of the glenohumeral joint with a soft-tissue repair only (n=1).
Patients were followed at routine time points with repeat imaging of the surgical site and lungs every 3-4 months for the first two years postoperative, every 4-6 months for year 3, every 6 months for years 4 and 5, and then annually for years 5-10. All surviving patients had at least 2-years of clinical follow-up, with a median follow-up of 10 years (IQR=24 years).
Statistical analysis. Data are reported as mean with standard deviations and medians with interquartile ranges, with whole numbers and percentages where appropriate. Postoperative active shoulder range of motion was evaluated with active forward elevation in the plane of the body and functional outcomes were measured using the Musculoskeletal Tumor Society (MSTS) score (18). Continuous variables were compared using the unpaired Welch’s t-test and Mann-Whitney U-tests and categorical variables were compared with the Fisher’s Exact test. Survival estimates were calculated using the Kaplan-Meier survival method with univariate Cox Hazard Regression. All tests were two-sided. p-Values <0.05 were considered statistically significant.
Results
Oncologic outcomes. Following surgery, tumor recurrence occurred in five patients (36%), with four patients developing local recurrence and metastatic disease and one patient developing isolated metastatic disease (Table II). Of these patients, three died of disease at 8-months, 9-months, and 40-months postoperative. The 2-, 5-, and 10-year disease-specific survival was 85%, 76%, and 76%, respectively. Of the factors analyzed (Table III), the development of a local recurrence was associated with worse disease-specific survival (HR=13.19, 95%CI=1.10-158.0, p=0.04).
Patient outcome following surgical resection.
Factors associated with oncology outcomes.
All local and distant disease recurrences occurred within the first two years of surgery. The 1-, 2-, and 5-year local recurrence-free survival was 85%, 85%, and 76%, respectively. The local recurrences were treated with either surgical resection (n=3) or definitive radiotherapy in the setting of wide-spread metastatic disease (n=1). No analyzed factor was associated with local recurrence. The 1-, 2-, and 5-year metastatic-free survival was 71%, 64%, and 64%, respectively. All these patients developed pulmonary metastatic disease; however, three patients also developed additional sites of disease, including the liver (n=1), adrenal (n=1), and bone (n=1). No analyzed factors were found to be associated with the development of metastatic disease.
Surgical and functional outcomes. Surgical complications occurred in eight patients (57%), leading to a repeat surgical procedure in four. The most common postoperative complication and indication for a secondary surgical procedure was a wound complication (n=3). The additional surgical procedure was performed for a periprosthetic fracture. Complications were associated (p<0.01) with either the use of an implant or allograft (n=7 of 7, 100%) versus a reconstruction where no implant or allograft was utilized (n=1 of 7, 14%). Although complications led to additional surgical procedures, there were no cases of amputation, with a 100% limb salvage rate.
Following surgery, the median forward elevation and external rotation at the shoulder at the most recent follow-up was 42±61° and 12±16°, respectively. In addition, the mean MSTS93 rating was 61±19%. The extent of resection, including the humerus and either a partial or total scapulectomy, was associated with differences in forward elevation and range of motion; however, it did not impact the overall MSTS93 rating (Table IV).
Functional outcomes.
Discussion
The scapula is an uncommon location for osteosarcoma, and due to the importance of the scapula for shoulder motion, reconstruction following oncologic resection can be challenging. In the current study, all patients were able to undergo a limb salvage procedure; however, a high rate of complications was associated with reconstruction of the shoulder. Despite the high rate of complications, many patients were alive at the most recent follow-up.
In the upper extremity and periscapular region, bone sarcomas are more common than soft-tissue sarcomas; however, among bone sarcomas, osteosarcomas occur rarely (6, 19, 20). In a series by Kaiser et al. (6), the authors analyzed the incidence of bone tumors of the scapula and found that osteosarcoma accounted for only 5% of all bone tumors. In addition, when compared to osteosarcoma located in other extremities, osteosarcoma of the upper extremity has been found to be associated with increased mortality in adults (21). Due to the rarity of scapular osteosarcoma, delay in diagnosis may potentially impact the outcome by delaying treatment initiation (22). Currently, one of the largest series includes 12 patients with scapular osteosarcoma (23). In this series, the authors noted only one local recurrence and the development of metastatic disease in the same patient (23).
Although survival of patients with osteosarcoma has improved over the past several decades, the development of a local recurrence is associated with a poor prognosis, especially if the local recurrence develops within the first year postoperative (24, 25). In the current series, all local recurrences occurred within the first two years after surgery, and local recurrence was associated with disease-related mortality. Of all the factors analyzed in the current series, only local recurrence was associated with disease outcome. This is likely due to the small sample size; however, it highlights the importance of local control in these patients.
Various factors have been found to be associated with limb salvage in patients with osteosarcoma of the upper extremity (13). For scapular resections, the amount of the remaining scapula has been found to be associated with functional outcomes, as preservation of the scapular spine and glenoid leads to improved shoulder motion and stability (26). In addition to preserving the bony scapula, preservation of the axillary nerve is also critical for powering the deltoid muscle (27). These factors were all important in the outcomes of the patients in the current study, with preservation of the axillary nerve and a partial scapulectomy all leading to improved functional outcomes for these patients.
Study limitations. Since this was a retrospective study, the collection of our data was limited. Although our sample size is larger compared to the existing literature, our study size is small due to the rarity of osteosarcoma localized to the scapula. The study spans over a 30-year period during which imaging, surgical, and systemic therapy have evolved. Functional outcomes were assessed by different specialists, making them prone to error, and were collected at a single time point.
Overall osteosarcoma of the scapula is rare, with local control of the tumor essential in the survival of patients. Although functional outcomes can be worse in patients with larger resections, patients are able to maintain a functional limb but should be warned about the high risk of postoperative complications.
Footnotes
Authors’ Contributions
Garayua-Cruz: Drafting of initial and final manuscript, data collection, data analysis; Broida: Review and editing of final manuscript, data collection, data analysis; Robinson: Review and editing of final manuscript; Okuno: Review and editing of final manuscript; Ho: Review and editing of final manuscript; Siontis: Review and editing of final manuscript; Sherman: Review and editing of final manuscript; Goulding: Review and editing of final manuscript; Houdek: rafting of initial and final manuscript, data analysis, supervision.
Conflicts of Interest
The Authors have no conflicts of interest to declare regarding this study.
- Received November 12, 2024.
- Revision received November 25, 2024.
- Accepted November 26, 2024.
- Copyright © 2025 The Author(s). Published by the International Institute of Anticancer Research.
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY-NC-ND) 4.0 international license (https://creativecommons.org/licenses/by-nc-nd/4.0).
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