Dedifferentiated chondrosarcoma of the pelvis: clinical outcomes and current treatment

Rare Dedifferentiated Periosteal Chondrosarcoma with 11-Year Metastatic Relapse: A Case Report

A 50-year-old man presented for evaluation of a periscapular mass. Biopsy suggested a low-grade chondrosarcoma; however, the resected specimen revealed a grade 2 chondrosarcoma with a low-grade dedifferentiated mesenchymal component. The mass multiply recurred as chondrosarcoma without a dedifferentiated component before the patient developed lung metastases of chondrosarcoma without a dedifferentiated component 11 years after the initial diagnosis and died of disease. This is one of the first reported cases of a dedifferentiated chondrosarcoma with low-grade dedifferentiated component. While overall prognosis may be better than in typical dedifferentiated chondrosarcoma, this tumor demonstrated numerous local recurrences as well as metastasis.

Patient-Derived Spheroid Culture Models Are Better Than Monolayer Models in Chondrosarcoma Research

Purpose

Chondrosarcoma (CSA) are mesenchymal tissue-derived bone tumors. CSA mainly occurs in older people. CSA has demonstrated resistance to chemotherapy and radiation; complete surgical removal with negative margins is the only treatment option. In the case of metastatic CSA, the chance of survival is meager. Since the conventional two-dimensional cell culture models failed to retain tumor characteristics, developing preclinical models mimicking the disease with the highest fidelity is paramount for personalized treatments.

Methods

In this study, we established spherical cultured cells as new models for CSA. First, we demonstrated that CSA cells could form spheroids when cultured in ultra-low attachment plates. Next, tissue samples from CSA patients were collected and processed into primary cells, which were subsequently cultured as primary spheroids. The growth rate of primary spheroids was monitored and the histology of mature spheroids were characterized. These primary spheroids were used in drug susceptibility studies where traditional doxorubicin therapy and our novel disulfiram-copper therapy were tested.

Results

Compared with conventional monolayer cultures, spheroids better recapitulated the features of the in vivo tumor in the aspect of the formation of extracellular matrix. In the drug susceptibility study, spheroids demonstrated high resistance to the classic therapies, suggesting that monolayer cultures may give false positive results. Therefore, using spheroids for drug research and development in the CSA field should provide more accurate results.

Conclusion

In summary, our study of primary CSA spheroids brought new insight into their chemoresistance and demonstrated its potential for personalized treatment of CSA in clinical medicine.

Dedifferentiated Chondrosarcoma from Molecular Pathology to Current Treatment and Clinical Trials

Dedifferentiated chondrosarcoma (DDCS) is a rare subtype of chondrosarcoma, a primary cartilaginous malignant neoplasm. It accounts for up to 1-2% of all chondrosarcomas and is generally associated with one of the poorest prognoses among all chondrosarcomas with the highest risk of metastasis. The 5-year survival rates range from 7% to 24%. DDCS may develop at any age, but the average presentation age is over 50. The most common locations are the femur, pelvis humerus, scapula, rib, and tibia. The standard treatment for localised disease is surgical resection. Most patients are diagnosed in unresectable and advanced stages, and chemotherapy for localised and metastatic dedifferentiated DDCS follows protocols used for osteosarcoma.

Secondary Peripheral Dedifferentiated Chondrosarcoma: A Case Report with Special Emphasis on the Radiology/Pathology Correlation

CASE

In a 54-year-old man, imaging findings suggested a malignant bone tumor having 2 distinct components of the left ilium. Histopathologically, the resected tumor was diagnosed as dedifferentiated chondrosarcoma (CS) arising in secondary peripheral CS.

CONCLUSION

Dedifferentiated CS consists of a high-grade noncartilaginous sarcoma adjacent to a preexisting low-grade CS, among which the peripheral type is extremely rare. Because the bimorphic imaging findings reflected the dedifferentiated area and the CS area, they were considered useful for diagnosis. In addition, the dedifferentiated area was localized to the tumor's edge, suggesting that the dedifferentiation originated from the cartilage cap.

Association Between Insurance Status and Chondrosarcoma Stage at Diagnosis in the United States: Implications for Detection and Outcomes

INTRODUCTION

Chondrosarcoma is a common primary bone tumor, and survival is highly influenced by stage at diagnosis. Early detection is paramount to improve outcomes. The aim of this study is to analyze the association between insurance status and stage of chondrosarcoma at the time of diagnosis.

METHODS

A comparative cross-sectional study was conducted using the Surveillance, Epidemiology and End Results database. Patients with a diagnosis of chondrosarcoma between 2007 and 2016 were included. Exposure variable was insurance status and the outcome chondrosarcoma staging at the time of diagnosis. Control variables included tumor grade, age, sex, race, ethnicity, marital status, place of residence, and primary site. Both unadjusted and adjusted (multiple logistic regression) odds ratios (ORs) and 95% confidence intervals (CIs) were computed to estimate the association between insurance status and stage.

RESULTS

An effective sample of 2,187 patients was included for analysis. In total, 1824 (83%) patients had health insurance (nonspecified), 277 (13%) had Medicaid, and the remaining 86 (4%) had no insurance. Regarding stage at diagnosis, 1,213 (55%) had localized disease, whereas 974 (45%) had a later stage at presentation. Before adjustment, the odds of being diagnosed at an advanced (regional/distant) stage were 55% higher in patients without insurance (unadjusted OR 1.55; 95% CI 1.003 to 2.39). After adjusting for potential confounders, the odds increased (adjusted OR 1.94; 95% CI 1.12 to 3.32). Variables with a significant association with a later stage at diagnosis included older age ( P < 0.001), male sex ( P < 0.001), pelvic location ( P < 0.001), and high grade ( P < 0.001).

CONCLUSION

Being uninsured in the United States increased the odds of a late-stage diagnosis of chondrosarcoma by 94% when compared with insured patients. Lack of medical insurance presumably leads to diminished access to necessary diagnostic testing, which results in a more advanced stage at diagnosis and ultimately a worse prognosis. Efforts are required to remediate healthcare access disparities.

LEVEL OF EVIDENCE

Level III.

Appendicular dedifferentiated chondrosarcoma: A management and survival study from the SEER database

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Dedifferentiated chondrosarcoma is an aggressive bone tumor with high rates of metastasis that severely impact the patient’s prognosis.

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Treatment usually consists of either a limb-salvage procedure or limb amputation, the former being more commonly performed.

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Size of the tumor severely impacts the likelihood of presenting metastasis at diagnosis.

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Female gender appears to be an important protective factor against death.

Introduction

Dedifferentiated chondrosarcoma (DDC) is an aggressive osseous neoplasm with a dismal prognosis. Treatment commonly involves limb-salvage surgery or amputation. In patients with appendicular DDC, we sought to describe demographic, clinical and treatment characteristics (1), analyze risk factors for metastasis (2) and overall death (3), and assess survival rates by treatment (4).

Materials and methods

Two-hundred-and-five patients from the SEER Database were included in our analysis. Demographic, clinical and treatment variables were analyzed. Multivariate regression was performed to identify risk factors. Survival analysis was performed using the Kaplan-Meier method.

Results

Fifty-one (24.9 %) of the patients included presented metastasis at diagnosis. The most common locations were the lungs, other sites, and bone. Surgery to the primary site was more common in patients without metastasis (94.2 %) than those with (78.2 %); limb-salvage procedures were more common than amputations. Tumors >8 cm (T2) and those discontinuous (T3) were more likely to present metastasis at diagnosis (OR = 2.54, p = 0.043 and OR = 7.4, p = 0.008, respectively). Female gender was found to be a protective factor for overall death on crude analysis (OR = 0.33, p = 0.019). Metastases to sites other than the lungs (M1b) had the highest risk of overall death (OR = 49, p = 0.01). Combination of surgery and chemotherapy showed a trend towards higher overall survival in non-metastatic patients (p = 0.1069 and p = 0.1703).

Conclusions

Appendicular DDC displays a high metastatic rate and low survival rates. The most common procedure is a limb-salvage surgery. Tumor size increases the risk of presenting metastases at diagnosis and female gender is a protective factor against death.

Dedifferentiated chondrosarcoma with minimal or small dedifferentiated component

Dedifferentiated chondrosarcoma (DDCS) is an aggressive bone sarcoma characterized by low-intermediate grade cartilage component with abrupt transition to a high-grade non-chondrosarcomatous component. Generally, the dedifferentiated (DD) component is large. However, rare cases have minimal (<1 cm) or small (1-2 cm) areas of DD. We describe the clinicopathologic features of such tumors and evaluate the prognostic significance of this finding compared to cases with large DD (>2 cm). Available slides were re-reviewed for assessment of histologic features. The medical record was reviewed for imaging studies and clinical characteristics. Thirty-five cases were included. Six patients had minimal DD, four had small DD and 25 had large DD. None of the minimal DD showed definitive imaging evidence of DD. Two minimal DD (33%) locally recurred and 2 (33%) developed distant metastases. None of the small DD cases showed definitive imaging evidence of DD. None of the small DD locally recurred and at least 1 (25%) developed distant metastases. There was no significant difference in age, gender, pelvic site, tumor size >8 cm, tumor necrosis or undifferentiated pleomorphic sarcoma-like morphology between minimal or small DD compared to large DD, though osteosarcomatous differentiation was significantly more common in large DD. There was no significant difference in overall survival between minimal or small DD compared to large DD (p = 0.81 and p = 0.17, respectively), or in progression-free survival (p = 0.47 and 0.29, respectively), or metastasis-free survival (p = 0.06 and 0.62, respectively). DDCS with minimal or small DD show similar demographic distribution, anatomic localization and histologic features to large DD. DD in these cases is unlikely to be detected on imaging. Furthermore, at least a subset of these tumors is extremely aggressive despite the limited extent of DD. This highlights the need for thorough gross and histologic examination and sampling.

Dedifferentiated Chondrosarcoma: A Case Series and Review of the Literature

BACKGROUND

Dedifferentiated chondrosarcoma (DCS) is a rare and aggressive malignancy with a poor prognosis. The purpose of this investigation was to describe our treatment and outcomes of 16 DCS patients at our institution and provide a review of the current literature.

METHODS

This study was a retrospective review over a consecutive twenty-year period. Data including treatment details and outcomes were recorded.

RESULTS

A total of 16 cases from 2000 to 2018 were identified. The median age (IQR) was 62 years (52; 69) and the majority of DCS arose in the femur (50%, n=8) and pelvis (25%, n=4). Fourteen (88%) cases underwent limb salvage/wide margin resection (n=13) or intralesional surgery (n=1). For all DCS, the median survival (IQR) was 46 months (12; 140), with both a five and ten-year probability of 32.1% (95% CI, 7.3% to 57.0%). At study conclusion, 81.3% (n=13) were deceased and 18.7% (n=3) were alive.

CONCLUSIONS

Our findings confirm the poor prognosis of DCS patients, with a five-year estimate of 32%. Together with existing literature, our data might help enable future strategic recommendation of these patients.

Surgical Treatment of Bone Sarcoma

Bone sarcomas are rare primary malignant mesenchymal bone tumors. The three main entities are osteosarcoma, chondrosarcoma, and Ewing sarcoma. While prognosis has improved for affected patients over the past decades, bone sarcomas are still critical conditions that require an interdisciplinary diagnostic and therapeutic approach. While radiotherapy plays a role especially in Ewing sarcoma and chemotherapy in Ewing sarcoma and osteosarcoma, surgery remains the main pillar of treatment in all three entities. After complete tumor resection, the created bone defects need to be reconstructed. Possible strategies are implantation of allografts or autografts including vascularized bone grafts (e.g., of the fibula). Around the knee joint, rotationplasty can be performed or, as an alternative, the implantation of (expandable) megaprostheses can be performed. Challenges still associated with the implantation of foreign materials are aseptic loosening and infection. Future improvements may come with advances in 3D printing of individualized resection blades/implants, thus also securing safe tumor resection margins while at the same time shortening the required surgical time. Faster osseointegration and lower infection rates may possibly be achieved through more elaborate implant surface structures.

Dedifferentiated chondrosarcoma of the middle finger arising from a solitary enchondroma: A case report

BACKGROUND

Dedifferentiated chondrosarcoma (DDCS) accounts for 10% of all chondrosarcomas and has the poorest outcome, with a 5-year survival rate of 7%-25%. DDCS commonly occurs in the femur and pelvis, whereas DDCS of the finger is extremely rare. Furthermore, the histological findings of preexisting solitary enchondroma samples are important and valuable for diagnosing malignant transformations.

CASE SUMMARY

We report our experience with DDCS in the proximal phalanx of the left middle finger of an 87-year-old woman. She had undergone surgery for enchondroma, with curettage and artificial bone grafting, 11 years ago, in the same location. Several years after the primary surgery, the left middle finger gradually started to enlarge, and the growth speed increased in the past year. Plain radiographs showed an expansive osteolytic lesion with calcifications and residual grafting material. Owing to the suspicion of malignancy, we performed ray amputation. Histological findings revealed an abrupt transition between the low-grade chondrosarcoma and dedifferentiated sarcoma components. The dedifferentiated components showed the features of a high-grade undifferentiated pleomorphic sarcoma. The patient was diagnosed with DDCS arising from a preexisting enchondroma. She had no local recurrence or distant metastasis and died of pneumonia 6 years and 10 months after the second surgery.

CONCLUSION

The histological findings of a precursor lesion showed a typical enchondroma, suggesting that DDCS can arise from enchondroma.

Dedifferentiated chondrosarcoma: current standards of care

Dedifferentiated chondrosarcomas are aggressive variants of chondrosarcoma, associated with poor outcomes. Tumor biphasism is the norm. The majority of these tumors are symptomatic at presentation. Radiologically, large soft tissue masses with bony destruction predominate. Treatment protocols of these tumors are not well defined. Surgical resection forms the standard of care for localized disease. (Neo)adjuvant therapies remain controversial as the results from multiple (mainly retrospective) studies remain conflicting. Age at presentation, stage and ability to obtain negative resection margins are important prognostic factors. The overall prognosis is dismal. Newer and novel therapies targeting the complex genetic makeup of these tumors have renewed interest in the adjuvant setting that could hold promise in the near future.

The Use of Anterior Superior Iliac Spine Osteotomy to Access the Anterior Column in Tumor Resection: A Case Report

CASE

A 24-year-old woman with chondrosarcoma of the superior pubic ramus underwent a Type III pelvic resection through an ilioinguinal approach, modified with anterior superior iliac spine (ASIS) osteotomy. The osteotomy mobilized the ASIS and sartorious distally, exposing the anterior wall and superior ramus. A custom cutting guide was placed on the anterior acetabular wall for en bloc superior ramus resection with hip-sparing osteotomy and negative margins.

CONCLUSION

ASIS osteotomy for sartorius mobilization improves visualization of the anterior column of the acetabulum and heals more reliably than sartorius tenotomy, therefore should be considered during tumor resection involving the anterior column, superior ramus, or acetabular wall.

Dedifferentiated chondrsarcoma: a clinicopathologic analysis of 25 cases

Background

To investigate the clinical, imaging and pathological features of dedifferentiated chondrosarcoma for better diagnosis.

Methods

Patients who had been confirmed to have dedifferentiated chondrosarcoma were enrolled in this study and analyzed in the clinical, imaging and pathological data.

Results

Twenty-five patients had pathologically confirmed dedifferentiated chondrosarcoma including 15 males and 10 females with an age range of 24–74 (median 58, interquartile range 49–65). Ten patients had the tumor at the femur, four at the ilium, two at the humerus, two at the tibia, two at cotyle, and one at each of the following locations: scapula, sacrum, rib, pubic branch, and calcaneus. Twenty-one patients had local pain and a soft tissue mass while the other four patients had only local pain without a soft tissue mass. Four patients had pathological fractures. Imaging showed extensive bone destruction with calcification inside the lesion and possible pathological fractures. On gross observation of the specimen, the chondrosarcoma components were usually located inside the bone, and the dedifferentiated sarcoma components were mainly located outside the bone. Microscopy showed the dedifferentiated tumor had two components: well-differentiated chondrosarcoma and poorly differentiated non-chondral sarcoma including malignant fibrous histiocytoma in eleven cases, osteosarcoma in ten cases, fibrosarcoma in two, liomyosarcoma in one, and lipoblastoma in the remaining one.. Followed up from 3 moths to 60 months (mean 15.6), eight patients died with a survival time of 10–23 months (mean 16), and the other 17 patients survived with the survival duration from three to 60 months (15).

Conclusion

Dedifferentiated chondrosarcoma is a fatal disease with multiple components, and most of the cases have dual morphological and imaging features of chondrosarcoma and non-chondrosarcoma. The imaging presentations are primarily of common central chondrosarcoma, combined with cortical destruction, soft tissue mass, and pathological fractures.

Primary chondrosarcoma of the penis in a young patient: A case report and review of the literature

INTRODUCTION

Primary chondrosarcoma of the penis is rare. We present a case of primary chondrosarcoma of the penis in a young patient.

CASE PRESENTATION

A 35-year-old man presented with a painless mass at the base of his penis for the past 6 months. Incisional biopsy of the lesion revealed a chondrosarcoma. Pelvic magnetic resonance imaging and computed tomography of the thorax, abdomen, and pelvis ruled out a primary lesion in the bones and soft tissues. The patient rejected total penectomy and decided to start chemoradiotherapy followed by local tumor resection.

CONCLUSION

Primary chondrosarcoma of the penis is rare. Interdisciplinary management plays an important role in planning the therapy for rare tumors. A combined chemoradiation therapy can be followed by penis-preserving surgery to improve the quality of life in young patients with proximal penile tumors.

Successful treatment of a dedifferentiated chondrosarcoma of the proximal humerus with a hemicortical articular surface sparing allograft: A case report

INTRODUCTION

Dedifferentiated chondrosarcomas are rare and highly malignant tumors that require wide surgical resection. Survival is extremely poor without adequate surgical margins. We present a case of articular sparing surgery of the shoulder for dedifferentiated chondrosarcoma with excellent functional outcomes and no evidence of disease after fifty-six months.

PRESENTATION OF CASE

A 29-year-old male was found to have a non-metastatic right proximal humerus dedifferentiated chondrosarcoma. He underwent resection with clear one centimeter margins sparing the medial cortex and the articular surface. Reconstruction of the bone was accomplished using a hemicortical allograft. A dermal allograft was used to help reconstruct the rotator cuff to the allograft bone. At fifty-six months after surgery he has excellent functional range of motion. His current MSTS, Quick Dash, and Constant Shoulder scores are 29, 2.3, and 80, respectively. He has remained free of disease, is back to work without restrictions and is active in outdoor activities.

DISCUSSION

Dedifferentiated chondrosarcoma has high recurrence and poor survival rates. Adequate surgical resection is vital for its treatment. Previously described reconstructive techniques have consisted of articular replacement with a prosthesis, allograft, or allograft-prosthetic composites. To our knowledge, this is the first report of an articular sparing reconstruction for dedifferentiated chondrosarcoma with fifty-six month survival and functional outcomes. When possible, sparing the articular surface can provide good functional outcomes that improve over time.

CONCLUSION

If adequate surgical margins can be obtained, an articular surface sparing reconstruction of the shoulder can provide effective functional outcomes and an alternative to joint replacement.

Surgical and oncological outcomes after hindquarter amputation for pelvic sarcoma

Aims

Survival rates and local control after resection of a sarcoma of the pelvis compare poorly to those of the limbs and have a high incidence of complications. The outcome for patients who need a hindquarter amputation (HQA) to treat a pelvic sarcoma is poor. Our aim was to evaluate the patient, tumour, and reconstructive factors that affect the survival of the patients who undergo HQA for primary or recurrent pelvic sarcoma.

Methods

We carried out a retrospective review of all sarcoma patients who had undergone a HQA in a supraregional sarcoma unit between 1996 and 2018. Outcomes included oncological, surgical, and survival characteristics.

Results

A total of 136 patients, with a mean age of 51 (12 to 83) underwent HQA, 91 for a bone sarcoma and 45 for a soft tissue sarcoma. The overall survival (OS) after primary HQA for a bone sarcoma was 90.7 months (95% confidence interval (CI) 64.1 to 117.2). In patients undergoing a secondary salvage HQA it was 90.3 months (95% CI 58.1 to 122.5) (p = 0.727). For those treated for a soft tissue sarcoma (STS), the mean OS was 59.3 months (95% CI 31.1 to 88.6) for patients with a primary HQA, and 12.5 months (95% CI 9.4 to 15.5) for those undergoing a secondary salvage HQA (p = 0.038). On multivariate analysis, high histological grade (hazard ratio (HR) 2.033, 95% CI 1.127 to 3.676; p = 0.018) and a diagnosis of STS (HR 1.653, 95% CI 1.027 to 2.660; p = 0.039) were associated with a poor prognosis. The 30-day mortality for patients with curative intent was 0.8% (1/128). For those in whom surgery was carried out with palliative intent it was 33.3% (2/6) (p = 0.001). In total, 53.7% (n = 73) of patients had at least one complication with 23.5% (n = 32) requiring at least one further operation. Direct closure was inferior to flap reconstruction in terms of complete primary wound healing (60.0% (3/5) vs 82.0% (82/100); p = 0.023).

Conclusion

In carefully selected patients HQA is associated with satisfactory overall survival, with a low risk of perioperative mortality, but considerable morbidity. However, caution must be exercised when considering the procedure for palliation due to the high incidence of early postoperative mortality. Cite this article: Bone Joint J 2020;102-B(6):788–794.

Prognostic Factors in Dedifferentiated Chondrosarcoma: A Retrospective Analysis of a Large Series Treated at a Single Institution

Background

Dedifferentiated chondrosarcomas (DDCSs) are highly malignant tumors with a dismal prognosis and present a significant challenge in clinical management.

Methods

In an IRB approved retrospective protocol, we identified 72 patients with DDCS treated at our institution between 1993 and 2017 and reviewed clinicopathological characteristics, treatment modalities, and outcomes to analyze prognostic factors.

Results

Femur (44.4%), pelvis (22.2%), and humerus (12.5%) were most commonly involved sites. Twenty-three patients (31.9%) presented with distant metastasis, and 3 (4.2%) of them also had regional lymph node involvement. The median overall survival (OS) was 13.9 months. On multivariate analysis, pathological fracture, larger tumor size, lymph node involvement, metastasis at diagnosis, extraosseous extension, and undifferentiated pleomorphic sarcoma component correlated with worse OS, whereas surgical resection and chemotherapy were associated with improved OS. For progression-free survival (PFS), pathological fracture and metastasis at diagnosis showed increased risk, while chemotherapy was associated with decreased risk. Among patients who received chemotherapy, doxorubicin and cisplatin were significantly associated with improved PFS but not OS. Among patients without metastasis at diagnosis, 17 (34.7%) developed local recurrence. Thirty-one (63.3%) developed distant metastases at a median interval of 18.1 months. On multivariate analysis, R1/R2 resection was related with local recurrence, while macroscopic dedifferentiated component was associated with distant metastasis.

Conclusions

The prognosis of DDCS is poor. Complete resection remains a significant prognostic factor for local control. Chemotherapy with doxorubicin and cisplatin seems to have better PFS. More prognostic, multicenter trials are warranted to further explore the effectiveness of chemotherapy in selected DDCS patients.

Primary osteosarcoma in elderly patients: A report of three cases

Osteosarcoma is the most common type of primary malignant bone tumor in children and young adults. However, primary osteosarcoma in elderly patients is rare. The present study reports 3 cases of advanced osteosarcoma in elderly patients. The pathological findings in all 3 cases confirmed the diagnosis of primary osteosarcoma. Notably, each patient received different treatment options. Chemoradiotherapy was recommended in case 1 due to the age of the patient. However, the patient requested to be discharged and was lost to follow-up. Conversely, in case 2, the 62-year-old female patient underwent systemic chemotherapy, but no surgical treatment, and in case 3, the 51-year-old male patient underwent complete tumor resection and received systemic chemotherapy for late tumor recurrence. Early diagnosis of osteosarcoma in elderly patients is difficult, and misdiagnosis or a missed diagnosis is common. In clinical practice, bone tumors in elderly patients should be investigated carefully. Imaging examinations are essential for diagnosis, and biopsy is required for confirmation. However, the efficacy of chemotherapy for elderly patients with primary osteosarcoma remains uncertain. Collectively, due to the small number of reports of osteosarcoma in the elderly population, the 3 cases in the present study raise awareness of this rare condition.

[Hemipelvectomy for pelvic sarcomas]

BACKGROUND

Hemipelvectomy is an important technique for the treatment of pelvic sarcomas.

OBJECTIVES

Presentation of the technical overview, as well as surgical and oncological outcomes of sarcoma patients treated with pelvic tumor resections and treatment recommendations.

METHODS

Retrospective analysis of 160 patients treated by pelvic tumor resection for chondrosarcoma between 1977 and 2014.

RESULTS

Chondrosarcoma was the most common diagnosis leading to pelvic tumor resection in this collective (38%). The mean patient age at operation was 49 years. 44 patients were treated for G1, 83 patients for G2 and 33 patients for G3 or dedifferentiated chondrosarcoma. The mean tumor diameter was ≥10 cm in 76.1% of cases. Limb salvaging operations were possible in 82.5% of patients. The most common reconstruction technique was hip transposition (38.7%). Clear resection margins were achieved in 86.9% (R0). Local recurrence was observed in 22.5%. Distant pulmonal metastasis was diagnosed in 25% of patients. Grading-specific survival was 81.8% for G1, 59% for G2 and 24.2% for G3 or dedifferentiated chondrosarcoma with a mean survival of 84.4, 89 and 69.4 months respectively.

CONCLUSIONS

Pelvic tumor resection with clear margins is the most important known positive predictive local factor affecting overall outcomes, in addition to uncontrollable factors such as grading and tumor size. Defect reconstruction depends on multiple factors such as patient age and adjuvant therapy. The stage of the disease has the greatest impact on overall survival rates and should be considered when contemplating pelvic tumor resections in sarcoma patients.