Role of surgical margin on local recurrence in high risk extremity osteosarcoma: a case-controlled study

Pediatric Osteosarcoma: Correlation of Imaging Findings with Histopathologic Features, Treatment, and Outcome

Osteosarcoma is the most common primary bone sarcoma in children. Imaging plays a pivotal role in diagnostic workup, surgical planning, and follow-up monitoring for possible disease relapse. Survival depends on multiple factors, including presence or absence of metastatic disease, chemotherapy response, and surgical margins. At diagnosis, radiography and anatomic MRI are used to characterize the primary site of disease, whereas chest CT and whole-body bone scintigraphy and/or PET are used to identify additional sites of disease. Treatment starts with neoadjuvant chemotherapy, followed by en bloc tumor resection and limb reconstruction, and finally, adjuvant chemotherapy. Preoperative planning requires precise tumor delineation, which traditionally has been based on high-spatial-resolution anatomic MRI to identify tumor margins (medullary and extraosseous), skip lesions, neurovascular involvement, and joint invasion. These findings direct the surgical approach and affect the options for reconstruction. For skeletally immature children, the risk of cumulative limb-length discrepancy and need for superior longevity of the reconstruction have led to the advent and preferential use of several pediatric-specific surgical techniques, including rotationplasty, joint preservation surgery, autograft or allograft reconstruction, and extendible endoprostheses. A better understanding of the clinically impactful imaging features can directly and positively influence patient care. Online supplemental material is available for this article. ^©RSNA, 2022.

Clinical outcomes of endoprosthetic reconstruction for proximal femoral resection

INTRODUCTION

The proximal femur is a common site for primary sarcomas and metastatic lesions. Although the early results of tumor prostheses are promising, the long-term results of reconstruction are unknown. The purpose of this study is to evaluate the prognostic factors affecting prosthesis survival and complications after proximal femoral resection and reconstruction.

METHODS

We reviewed the results of 68 patients who underwent proximal femoral resection and reconstruction with a modular bipolar-type tumor prosthesis between 2005 and 2017. The mean follow-up was 55.6 months (range 6-172 months). There were 50 male and 18 female patients with a mean age of 41.5 years (range 11-80 years). Cumulative survival analysis was performed to analyze the risk factors of prosthesis survival. We also evaluated the complications after operation.

RESULTS

Fourteen (21%) patients required further surgery at a mean 37 months post-operatively (range 5-125 months). There were three cases of infection (4%), six of local recurrence (9%), three of acetabular erosion (4%) and two of stem loosening (3%). The implant survival rates were 83.9% at 5 years and 59.8% at 10 years. Prosthesis survivals did not differ based on fixation method (P = 0.085), age (P = 0.329) or resection length (P = 0.61). Acetabular chondrolysis was identified in 18 (26%) patients and longer resection length (≥20 cm) showed a trend for risk of acetabular wear (P = 0.132).

CONCLUSION

The results of proximal femoral resection and reconstruction with a modular bipolar-type prosthesis were found to be acceptable with infection and local recurrence as short-term complications and loosening and acetabular erosion as long-term complications.

Can Navigation Improve the Ability to Achieve Tumor-free Margins in Pelvic and Sacral Primary Bone Sarcoma Resections? A Historically Controlled Study

BACKGROUND

Anatomic and surgical complexity make pelvic and sacral bone sarcoma resections challenging. Positive surgical margins are more likely to occur in patients with pelvic and sacral bone sarcomas than in those with extremity sarcomas and are associated with an increased likelihood of local recurrence. Intraoperative navigation techniques have been proposed to improve surgical accuracy in achieving negative margins, but available evidence is limited to experimental (laboratory) studies and small patient series. Only one small historically controlled study is available. Because we have experience with both approaches, we wanted to assess whether navigation improves our ability to achieve negative resection margins.

QUESTIONS/PURPOSES

Are navigated resections for pelvic and sacral primary bone sarcomas better able to achieve adequate surgical margins than nonnavigated resections?

METHODS

Thirty-six patients with pelvic or sacral sarcomas treated with intraoperative navigation were retrospectively compared with 34 patients undergoing resections without navigation. All patients underwent resections between 2000 and 2017 with the intention to achieve a wide margin. Patients in the navigation group underwent surgery between 2008 and 2017; during this period, all resections of pelvic and sacral primary bone sarcomas with the intention to achieve a wide margin were navigation-assisted by either CT fluoroscopy or intraoperative CT. Patients in the control group underwent surgery before 2008 (when navigation was unavailable at our institution), to avoid selection bias. We did not attempt to match patients to controls. Nonnavigated resections were performed by two senior orthopaedic surgeons (with 10 years and > 25 years of experience). Navigated resections were performed by a senior orthopaedic surgeon with much experience in surgical navigation. The primary outcome was the bone and soft-tissue surgical margin achieved, classified by a modified Enneking system. Wide margins (≥ 2 mm) and wide-contaminated margins, in which the tumor or its pseudocapsule was exposed intraoperatively but further tissue was removed to achieve wide margins, were considered adequate; marginal (0-2 mm) and intralesional margins were considered inadequate.

RESULTS

Adequate bone margins were achieved in more patients in the navigated group than in the nonnavigation group (29 of 36 patients [81%] versus 17 of 34 [50%]; odds ratio, 4.14 [95% CI, 1.43-12.01]; p = 0.007). With the numbers available, we found no difference in our ability to achieve adequate soft-tissue margins between the navigation and nonnavigation group (18 of 36 patients [50%] versus 18 of 34 [54%]; odds ratio, 0.89 [95% CI, 0.35-2.27]; p = 0.995).

CONCLUSIONS

Intraoperative guidance techniques improved our ability to achieve negative bony margins when performing surgical resections in patients with pelvic and sacral primary bone sarcomas. Achieving adequate soft-tissue margins remains a challenge, and these margins do not appear to be influenced by navigation. Larger studies are needed to confirm our results, and longer followup of these patients is needed to determine if the use of navigation will improve survival or the risk of local recurrence.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Treatment-Related Prognostic Factors in Managing Osteosarcoma around the Knee with Limb Salvage Surgery: A Lesson from a Long-Term Follow-Up Study

Purpose

The aim of this study was to assess the treatment-related factors associated with local recurrence and overall survival of patients with osteosarcoma treated with limb-salvage surgery.

Patients and Methods

Treatment-related factors were analyzed to evaluate their effects on local recurrence-free survival (LRFS) and overall survival (OS) in 182 patients from 2004 to 2013.

Results

The mean length of follow-up was 73.4 ± 34.7 months (median, 68 months; range, 12-173 months), and 63 patients died by the end of the follow-up. The 5-year and 10-year overall survival rates were 68.6 ± 6.6% and 59.4 ± 10.6%, respectively. Univariate analysis showed that treatment-related prognostic factors for overall survival were prolonged symptom intervals >=60 days, biopsy/tumor resection performed by different centers, previous medical history, incomplete preoperative chemotherapy (<8 weeks), and prolonged postoperative interval >21 days. In the multivariate analysis, biopsy/tumor resection performed by different centers, incomplete implementation of planned new adjuvant chemotherapy, and delayed resumption of postoperative chemotherapy (>21 days) were risk factors for poor prognosis; biopsy/tumor resection performed by different centers and tumor necrosis <90% were independent predictors of local recurrence.

Conclusion

For localized osteosarcoma treated with limb-salvage surgery, it is necessary to optimize timely standard chemotherapy and to resume postoperative chemotherapy to improve survival rates. Biopsies should be performed at experienced institutions in cases of developing local recurrence.

Clinical outcome of various limb salvage surgeries in osteosarcoma around knee: Megaprosthesis, extracorporeal irradiation and resection arthrodesis

Background

We evaluated the outcome and the survival rate of Limb salvage surgeries (LSSs) in osteosarcoma around knee by using megaprosthesis, ECI autograft, and modified arthrodesis of the knee with metallic plus bone cement (MAMC).

Methods

We reviewed 35 cases of osteosarcoma around the knee that was treated by megaprosthesis, ECI autograft and MAMC from 2012 to 2017. The survival, local recurrence, metastases, complications and functional MSTS score were evaluated for each operation technique. Kaplan-Meier was used to describe the survival rate for each technique.

Result

Megaprostheses group had an excellent MSTS score (78.7%), the ECI group (72.3%) and MAMC group (68.4%). Local recurrence occurred in the megaprothesis group (0%), the ECI group (9.1%) and MAMC group (20%). Infection occurred in 3 cases of ECI (13.6%) while only 2 (40%) cases in MAMC group and 1 case (12.5%) in the megaprostheses group. Aseptic loosening occurred in the megaprostheses group 1 case (12.5%) and MAMC 1 case (20%). Metastases occurred in 18.2% of the ECI group compared to 25% of the megaprostheses group and 40% of the MAMC group. The megaprosthesis group had an overall survival rate of 90.9 months, whilst the ECI group is on 94.6 months and the MAMC group was 47.2 months.

Conclusion

Megaprosthesis showed good-excellent functional outcome and survival rate. ECI that is an option in LSS has good functional outcome as well. Knee arthrodesis with MAMC it is still an option to perform LSS even in the advanced local stage of the disease.

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Various reconstruction options are available for the reconstruction of the distal femur and proximal tibia osteosarcoma.

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Megaprosthesis showed good-excellent functional outcome and survival rate.

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ECI that is an option in LSS has good functional outcome as well.

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Knee arthrodesis with MAMC it is still an option to perform LSS even in the advanced local stage of the disease.

The current status of MRI in the pre-operative assessment of intramedullary conventional appendicular osteosarcoma

Osteosarcoma is the commonest primary malignant bone tumour in children and adolescents, the majority of cases being conventional intra-medullary high-grade tumours affecting the appendicular skeleton. Treatment is typically with a combination of neo-adjuvant chemotherapy, tumour resection with limb reconstruction and post-operative chemotherapy. The current article reviews the role of magnetic resonance imaging (MRI) in the pre-operative assessment of high-grade central conventional osteosarcoma.

Magnetic resonance imaging features for the differential diagnosis of local recurrence of bone sarcoma after prosthesis replacement

Objective

To explore the imaging features of local recurrences (LRs) based on magnetic resonance imaging (MRI) after oncological orthopaedic surgery with prosthesis reconstruction.

Methods

A total of 78 cases totalling 157 scans were retrospectively reviewed. Patients with nodule/mass-like signals were retrospectively classified into LR, infectious pseudotumour, and asymptomatic pseudotumour according to clinicopathological data. LRs were histologically confirmed, and the patients without recurrences were followed up for at least 2 years. Mass size distribution and radiological characteristics were analysed for differential diagnosis of the LR versus pseudotumour.

Results

Thirty-three of 78 cases were positive with nodule/mass-like signal findings on the post-operative MRI images. By analysing the size distribution, we found that masses >2.1 cm (14) were almost attributable (98% specificity) to LRs and mostly (84.6%) timely treated. Contrarily, masses ≤2.1 cm (19) are challenging for differential diagnosis of LRs versus pseudotumour and were undertreated in five of the nine LR cases. MRI characteristics of masses ≤2.1 cm were found to be highly heterogeneous, with solid appearance, adjacent infiltration, and less peritumour oedema being significant indicators for LRs (P＜0.05). Receiver operating characteristic curve showed area under curve of 0.93 for this predictive model.

Conclusions

For the post-operative MRI surveillance of oncological orthopaedic surgery with prosthesis reconstruction, a mass larger than 2.1 cm was highly specific for recurrence. When a mass was smaller than 2.1 cm, more solid property, more adjacent tissue infiltration, and less muscular oedema indicated recurrence rather than a benign mass.

The translational potential of this article

There has been very little data associated with the post-operative magnetic resonance imaging features indicating recurrence in patients with malignant bone sarcoma after prosthesis replacement. This study could help develop diagnostic features of magnetic resonance imaging for differentiating recurrence from benign changes in these patients after prosthesis replacement.

Adipose-derived mesenchymal stem cells promote osteosarcoma proliferation and metastasis by activating the STAT3 pathway

Osteosarcoma is the most common primary bone malignancy in children and young adults, but the role of adipose-derived mesenchymal stem cells (ADSCs) in the rapid progression of osteosarcoma is still unclear. Here, we found that ADSCs promoted tumour growth and invasion by increasing matrix metalloproteinase 2/9 (MMP2/9) expression in tumour cells. The persistent activation of signal transducer and activator of transcription 3 (STAT3) has been shown to directly promote tumour growth by mediating a wide spectrum of cellular responses, and STAT3 activation was detected in osteosarcoma cells co-cultured with ADSCs or treated with ADSC-conditioned medium. Furthermore, siRNA-mediated STAT3 inhibition in osteosarcoma cells decreased cell proliferation and invasion and down-regulated MMP2/9 expression. In addition, a nude mouse model of osteosarcoma was established by injecting luciferase-labelled MG63 cells into the tibia. As shown in in vivo bioluminescence images, ADSCs promoted tumour cell proliferation, invasion progression and metastasis. STAT3 inhibition attenuated tumour growth and metastasis and prolonged the survival of these mice. After the siRNA treatment, the MMP2, MMP9 and Ki67 levels decreased. Based on these data, stromal ADSCs promote osteosarcoma progression by increasing STAT3 signalling-mediated MMP2/9 expression.

Factors associated with local recurrence in operated osteosarcomas: A retrospective evaluation of 95 cases from a tertiary care center in a resource challenged environment

BACKGROUND AND OBJECTIVES

Local control of disease is one of the main goals of osteosarcoma management. We conducted a retrospective evaluation of 95 operated cases of osteosarcoma over 7 years to know about the factors associated with local recurrence in resource-challenged environment of the developing world.

METHODS

The factors which were evaluated and compared between local recurrence and non-local recurrence groups included demographic profile, site of tumor, whether biopsy done outside, type of surgery (limb salvage or amputation), presence of pathological fracture, vicinity of neurovascular bundle, tumor volume, histological subtype, chemotherapy induced necrosis, surgical margins, and delay in surgery. The time to local recurrence after surgery was also noted in the local recurrence group.

RESULTS

At a mean follow-up of 2.8 years, biopsy done from outside the treating center and delay in surgery after completion of neo-adjuvant chemotherapy emerged as significant risk factors for local recurrence. Most of the local recurrences (80%) occurred within 12 months of the primary surgery.

CONCLUSIONS

Lack of financial resources and availability of few tertiary care centers dealing with musculoskeletal oncology in the developing countries, lead to overburden with a long waiting list for tumor surgery making the scenario different from the Western world.

Osteosarcoma Overview

Osteosarcoma (OS) is the most common primary malignancy of bone and patients with metastatic disease or recurrences continue to have very poor outcomes. Unfortunately, little prognostic improvement has been generated from the last 20 years of research and a new perspective is warranted. OS is extremely heterogeneous in both its origins and manifestations. Although multiple associations have been made between the development of osteosarcoma and race, gender, age, various genomic alterations, and exposure situations among others, the etiology remains unclear and controversial. Noninvasive diagnostic methods include serum markers like alkaline phosphatase and a growing variety of imaging techniques including X-ray, computed tomography, magnetic resonance imaging, and positron emission as well as combinations thereof. Still, biopsy and microscopic examination are required to confirm the diagnosis and carry additional prognostic implications such as subtype classification and histological response to neoadjuvant chemotherapy. The current standard of care combines surgical and chemotherapeutic techniques, with a multitude of experimental biologics and small molecules currently in development and some in clinical trial phases. In this review, in addition to summarizing the current understanding of OS etiology, diagnostic methods, and the current standard of care, our group describes various experimental therapeutics and provides evidence to encourage a potential paradigm shift toward the introduction of immunomodulation, which may offer a more comprehensive approach to battling cancer pleomorphism.

Epiphyseal Sparing and Reconstruction by Frozen Bone Autograft after Malignant Bone Tumor Resection in Children

Limb salvage surgery has become the standard treatment for malignant primary bone tumors in the extremities. Limb salvage represents a challenge in skeletally immature patients. Several treatment options are available for limb reconstruction after tumor resection in children. We report our results using the technique of epiphyseal sparing and reconstruction with frozen autograft bone in 18 children. The mean follow-up period for the all patients included in this study is 72 ± 26 m. Eight patients remained disease-free, seven patients lived with no evidence of disease, two were alive but with disease, and one patient died of the disease. Five- and ten-year rates of survival were 94.4%. Graft survival at 5 and 10 years was 94.4%. Functional outcome using the Enneking scale was excellent in 17 patients (94.4%) and poor in one patient (5.5%). Complications include 2 nonunions, 2 fractures, 2 deep infections, 1 soft tissue recurrence, and leg length discrepancy in 7 cases. This technique is a good reconstructive choice in a child with a nonosteolytic primary or secondary bone tumor, responsive to chemotherapy, without involvement of the articular cartilage. It is a straight forward, effective, and biological technique, which affords immediate mobilization of joints and possible cryoimmune effects, with excellent long term functional outcome and less complication.

Survival, recurrence, and function after epiphyseal preservation and allograft reconstruction in osteosarcoma of the knee

BACKGROUND

Bone tumor resections for limb salvage have become the standard treatment. Recently, intercalary tumor resection with epiphyseal sparing has been used as an alternative in patients with osteosarcoma. The procedure maintains normal joint function and obviates some complications associated with osteoarticular allografts or endoprostheses; however, long-term studies analyzing oncologic outcomes are scarce, and to our knowledge, the concern that a higher local recurrence rate may be an issue has not been addressed.

QUESTIONS/PURPOSES

We wanted to assess (1) the overall survival in patients treated with this surgical technique; (2) the percentage of local recurrence and limb survival, specifically the incidence of recurrence in the remaining epiphysis; (3) the frequency of orthopaedic complications, and, (4) the functional outcomes in patients who have undergone intercalary tumor resection.

METHODS

We analyzed all 35 patients with osteosarcomas about the knee (distal femur and proximal tibia) treated at our center between 1991 and 2008 who had resection preserving the epiphysis and reconstruction with intercalary allografts. Minimum followup was 5 years, unless death occurred earlier (mean, 9 years; range, 1-16 years), and no patients were lost to followup. During the study period, our indications for this approach included patients without metastases, with clinical and imaging response to neoadjuvant chemotherapy, that a residual epiphysis of at least 1 cm thickness could be available after a surgical margin width in bone of 10 mm was planned, and 16% of patients (35 of 223) meeting these indications were treated using this approach. Using a chart review, we ascertained overall survival of patients, oncologic complications such as local recurrence and tumor progression, limb survival, and orthopaedic complications including infection, fracture, and nonunion. Survival rates were estimated using the Kaplan-Meier method. Patient function was evaluated using the Musculoskeletal Tumor Society (MSTS)-93 scoring system.

RESULTS

Overall survival rate of the patients was 86% (95% CI, 73%-99%) at 5 and 10 years. Five patients died of disease. No patient had a local recurrence in the remaining bony epiphysis, but three patients (9%; 95% CI, 0%-19%) had local recurrence in the soft tissue. The limb survival rate was 97% (95% CI, 89%-100%) at 5 and 10 years. Complications treated with additional surgical procedures were recorded for 19 patients (54%), including three local recurrences, two infections, 11 fractures, and three nonunions. In 10 of these 19 patients, the allograft was removed. Only five of the total 35 study patients (14%) lost the originally preserved epiphysis owing to complications. The mean functional score was 26 points (range, 10-30 points, with a higher score representing a better result) at final followup.

CONCLUSIONS

Although the recurrence rate was high in this series, the small sample size means that even one or two fewer recurrences might have resulted in a much more favorable percentage. Because of this, future, larger studies will need to determine whether this is a safe approach, and perhaps should compare epiphyseal preservation with other possible approaches, including endoprosthetic reconstruction and/or osteoarticular allografts.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Usefulness of increased 18F-FDG uptake for detecting local recurrence in patients with extremity osteosarcoma treated with surgical resection and endoprosthetic replacement

OBJECTIVE

To investigate the changes of increased F-18 fluorodeoxyglucose ((18)F-FDG) uptake around the prosthesis and its ability to differentiate local recurrence from postsurgical change after endoprosthetic replacement in extremity osteosarcoma.

MATERIALS AND METHODS

A total of 355 positron emission tomography (PET)/computed tomography (CT) scans in 109 extremity osteosarcoma patients were retrospectively analyzed. All patients were followed up with (18)F-FDG PET/CT for more than 3 years after tumor resection. For semiquantitative assessment, we drew a volume of interest around the entire prosthesis of the extremity and measured the maximum standardized uptake value (SUV max). Independent samples t test was used to compare SUV max at each follow-up time. SUV max at 3 months (SUV1) and SUV max at the time of local recurrence in patients with recurrence or at the last follow-up in others (SUV2) were compared using the Mann-Whitney test. Diagnostic performances of PET parameters were assessed using ROC curve analyses.

RESULTS

Nine patients (8 %) showed a local recurrence. Mean SUV max at 3, 12, 24, and 36 months was 3.1 ± 1.5, 3.8 ± 1.9, 3.6 ± 1.9, and 3.7 ± 1.5 respectively. In ROC curve analysis, the combination of SUV2 >4.6 and ΔSUV >75.0 was a more useful parameter for predicting local recurrence than SUV2 or ΔSUV alone. The sensitivity, specificity, and accuracy for identifying local recurrence were 89, 76, 77 % for SUV2; 78, 81, 81 % for ΔSUV; and 78, 94, 93 % for the combined criterion respectively.

CONCLUSION

The combination of SUV2 and ΔSUV was more useful than the SUV2 or ΔSUV used alone for the prediction of local recurrence.

Postoperative infection and survival in osteosarcoma patients: Reconsideration of immunotherapy for osteosarcoma

There is controversy regarding the impact of infection on long-term prognosis in osteosarcoma patients. Clinical trials and experiments relating to this field could bring reconsideration of immunotherapy for osteosarcoma. The clinical records were reviewed of 125 osteosarcoma patients with a mean follow-up of 5.1±3.9 years (range, 0.5-19.8 years), and a review of the literature was also carried out. Chronic localized infections (but not systemic infection) were determined in 6 patients (4.8%). Similar chemotherapeutic regimens (P=1.00) and histological reactions (P=0.65) were observed in patients with or without infection. Tumor location of proximal tibia (P=0.04) was more common in infected patients. More amputations (P<0.001) were necessitated in infected patients due to uncontrolled infection. The 5-year overall survival rate and event-free survival rate in infected patients were 100%, which were significantly higher than that of the non-infected patients, of whom the rates were 54 and 43% respectively (log-rank test: total survival, P=0.01; tumor-free survival, P=0.01). Distant metastasis was an independent risk factor for survival determined by Cox regression analysis (P<0.001, 95 confidence interval, 1.59-3.98). These findings suggested infection was likely to have positive effects on survival in osteosarcoma patients, however, underlying mechanisms remain to be elucidated. Reconsideration of the association of infection and survival in osteosarcoma patients will help to explore novel therapeutic routes and targets in these patients.

Osteosarcoma: Diagnostic dilemmas in histopathology and prognostic factors

Osteosarcoma (OS), the commonest malignancy of osteoarticular origin, is a very aggressive neoplasm. Divergent histologic differentiation is common in OS; hence triple diagnostic approach is essential in all cases. 20% cases are atypical owing to lack of concurrence among clinicoradiologic and pathologic features necessitating resampling. Recognition of specific anatomic and histologic variants is essential in view of better outcome. Traditional prognostic factors of OS do stratify patients for short term outcome, but often fail to predict their long term outcome. Considering the negligible improvement in the patient outcome during the last 20 years, search for novel prognostic factors is in progress like ezrin vascular endothelial growth factor, chemokine receptors, dysregulation of various micro ribonucleic acid are potentially promising. Their utility needs to be validated by long term followup studies before they are incorporated in routine clinical practice.