Treatment algorithm for locally recurrent osteosarcoma based on local disease-free interval and the presence of lung metastasis

Engineering Bimetallic Polyphenol for Mild Photothermal Osteosarcoma Therapy and Immune Microenvironment Remodeling by Activating Pyroptosis and cGAS-STING Pathway

The immunosuppressive tumor microenvironment (ITME) of osteosarcoma (OS) poses a significant obstacle to the efficacy of existing immunotherapies. Despite the attempt of novel immune strategies such as immune checkpoint inhibitors and tumor vaccines, their effectiveness remains suboptimal due to the inherent difficulty in mitigating ITME simultaneously from both the tumor and immune system. The promotion of anti-tumor immunity through the induction of immunogenic cell death and activation of the cGAS-STING pathway has emerged as potential strategies to counter the ITME and stimulate systemic antitumor immune responses. Here, a bimetallic polyphenol-based nanoplatform (Mn/Fe-Gallate nanoparticles coated with tumor cell membranes is presented, MFG@TCM) which combines with mild photothermal therapy (PTT) for reversing ITME via simultaneously inducing pyroptosis in OS cells and activating the cGAS-STING pathway in dendritic cells (DCs). The immunostimulatory pathways, through the syngeneic effect, exerted a substantial positive impact on promoting the secretion of damage-associated molecular patterns (DAMPs) and proinflammatory cytokines, which favors remodeling the immune microenvironment. Consequently, effector T cells led to a notable antitumor immune response, effectively inhibiting the growth of both primary and distant tumors. This study proposes a new method for treating OS using mild PTT and immune mudulation, showing promise in overcoming current treatment limitations.

Controversies and Challenges in the Management of Osteosarcoma-an Indian Perspective

Osteosarcoma (OGS) is the most common primary bone tumor in children and adolescents which requires a multidisciplinary approach to management. Although chemotherapy and surgery can cure more than half of localized OGS cases, the unique challenges faced by resource-limited countries like India make this outcome difficult to achieve. Various questions in the management of OGS including role of high-dose methotrexate (HDMTX) in neoadjuvant setting, triplet vs doublet chemotherapy, intensification of chemotherapy based on response in setting of doublet, and indigenous prosthesis in setting of limb salvage need to be defined. Similarly, in the metastatic and recurrent setting, questions regarding intent of treatment, indications of chemotherapy, timing of surgery, and role of targeted therapies need clarification. Lack of randomized trials from India makes definite conclusions difficult, but an attempt can be made to define the best approach in the Indian scenario from available evidence. Hence, a critical review of literature from India and the West was done to define possible management approaches and highlight the lacuna for future research.

A novel method of light projection and modular jigs to improve accuracy in bone sarcoma resection

We developed a novel method using a combined light-registration/light-projection system along with an off-the-shelf, instant-assembly modular jig construct that could help surgeons improve bone resection accuracy during sarcoma surgery without many of the associated drawbacks of 3D printed custom jigs or computer navigation. In the novel method, the surgeon uses a light projection system to precisely align the assembled modular jig construct on the bone. In a distal femur resection model, 36 sawbones were evenly divided into 3 groups: manual-resection (MR), conventional 3D-printed custom jig resection (3DCJ), and the novel projector/modular jig (PMJ) resection. In addition to sawbones, a single cadaver experiment was also conducted to confirm feasibility of the PMJ method in a realistic operative setting. The PMJ method improved resection accuracy when compared to MR and 3DCJ, respectively: 0.98 mm versus 7.48 mm (p < 0.001) and 3.72 mm (p < 0.001) in mean corner position error; 1.66 mm versus 9.70 mm (p < 0.001) and 4.32 mm (p = 0.060) in mean maximum deviation error; 0.79°-4.78° (p < 0.001) and 1.26° (p > 0.999) in mean depth angle error. The PMJ method reduced the mean front angle error from 1.72° to 1.07° (p = 0.507) when compared to MR but was slightly worse compared to 0.61° (p = 0.013) in 3DCJ. The PMJ method never showed an error greater than 3 mm, while the maximum error of other two control groups were almost 14 mm. Similar accuracy was found with the PMJ method on the cadaver. A novel method using a light projector with modular jigs can achieve high levels of bone resection accuracy, but without many of the associated drawbacks of 3D printed jigs or computer navigation technology.

How to confront the high prevalence of pulmonary micro nodules (PMNs) in osteosarcoma patients?

PURPOSE

Pulmonary metastasis was a negative factor of osteosarcoma prognosis. However, there is no universal criteria to confirm pulmonary metastasis at pulmonary micro nodule (PMN, Dmax ≤ 5 mm) stage other than pathology. We aimed to identify prevalence of PMNs, determine prognosis of osteosarcoma with PMNs, and analyze risk factors related to PMN progression.

METHODS

We retrospectively reviewed 425 consecutive osteosarcoma patients. According to dynamic change in size and number of PMNs, patients were divided into PMN progression and non-progression group. Demographic data, initial laboratory data, radiological features, and oncological evaluations were analyzed. Cox regression was used to identify risk factors for PMN progression. Overall survival rate was measured and analyzed with Kaplan-Meier method. Differences with p < 0.05 were considered significant.

RESULTS

PMNs were found in 74% (315/425) osteosarcoma patients, half of whom (157/315) suffering PMN progression. Overall survival rate was 70.2%, while survival rates for PMN progression group and non-progression group were 53.40% and 87.40%, respectively. Clinical risk factors for PMN progression in certain patients included blood vessel invasion, extrapulmonary metastases, low tumour cell necrosis rate, and large tumour size. Radiologic risk factors included greatest diameter, distance to pleura, CT value, solid components, and smooth border.

CONCLUSION

PMN is quite common in osteosarcoma patients. PMN progression is related to both certain clinical and radiological factors, which could assist surgeons to determine its possibility to progress at an early stage.

Prognostic factors and treatment of relapsed osteosarcoma: A monocentric Tunisian retrospective study

BACKGROUND

This study aimed to explore the treatment modalities of relapsed osteosarcoma, treatment results, and prognostic factors.

METHODS

We conducted a retrospective study of patients treated for relapsed osteosarcoma between 2005 and 2019. Patient survival was compared according to age, performance status, time to relapse, and surgical treatment at the relapse. Values of p<0.05 were considered to indicate statistical significance.

RESULTS

We included 49 patients who were treated for osteosarcoma. During the 13-year study period, 16 patients had relapsed osteosarcoma (32.7%). Prognostic factors of relapse were age over 18 years (p = 0.03), axial tumors (p = 0.01), and positive surgical margins (p = 0.018). Nine patients had palliative chemotherapy at the time of relapse. After a median follow-up of 8 months (range: 4-65 months), the overall survival at 1 year, 2 years, and 5 years after diagnosis of the relapse was 46.7%, 31.1%, and 20.7%, respectively. Relapsed osteosarcoma patients who had good performance status, late relapse (after 12 months), as well as surgery of the relapsed disease had better overall survival (OS).

CONCLUSION

Surgical treatment of relapsed osteosarcoma should be performed whenever possible since it improves significantly the survival of patients. Good performance status and late relapse were also associated with better survival.

Management of Refractory Pediatric Sarcoma: Current Challenges and Future Prospects

Paediatric sarcomas are a heterogeneous group of disorders constituting bone sarcoma and various soft tissue sarcomas. Almost one-third of these presents with metastasis at baseline and another one-third recur after initial curative treatment. There is a huge unmet need in this cohort in terms of curative options and/or prolongation of survival. In this review, we have discussed the current treatment options, challenges and future strategies of managing relapsed/refractory paediatric sarcomas. Upfront risk-adapted treatment with multidisciplinary management remains the main strategy to prevent future recurrence or relapse of the disease. In the case of limited local and/or systemic relapse or late relapse, initial multimodality management can be administered. In treatment-refractory cases or where cure is not feasible, the treatment options are limited to novel therapeutics, immunotherapeutic approach, targeted therapies, and metronomic therapies. A better understanding of disease biology, mechanism of treatment refractoriness, identifications of driver mutation, the discovery of novel targeted therapies, cellular vaccine and adapted therapies should be explored in relapsed/refractory cases. Close national and international collaboration for translation research is needed to fulfil the unmet need.

What is the best clinical approach to recurrent/refractory osteosarcoma?

Introduction: Osteosarcoma is the most common malignant bone tumor. It is currently treated with pre-and postoperative chemotherapy, associated with surgical resection of the tumor.Area covered: Relapses occur in about one in three patients presenting with localized disease, and three in four of those with metastases at diagnosis. Relapsing disease carries a very poor prognosis, with 5-year survival rates ranging between 13% and 40%.Expert opinion: Patients with unilateral lung involvement or solitary lung metastases and a recurrence-free interval (RFI) longer than 24 months have a better prognosis, and could be managed with surgical resection and close observation. Complete surgical resection of all sites of disease remains essential to survival: patients unable to achieve complete remission have a catastrophic overall survival rate. The role of second-line chemotherapy is not at all clear, and no controlled studies are available on this topic. It is worth considering for patients unable to achieve complete surgical remission, and those with multiple metastases and/or a RFI <24 months. Given their dismal prognosis, patients with multiple sites of disease not amenable to complete surgical resection should also be considered for innovative therapeutic approaches.

Preoperative surgical risk stratification in osteosarcoma based on the proximity to the major vessels

Aims

The aim of this study was to determine the risk of local recurrence and survival in patients with osteosarcoma based on the proximity of the tumour to the major vessels.

Patients and Methods

A total of 226 patients with high-grade non-metastatic osteosarcoma in the limbs were investigated. Median age at diagnosis was 15 years (4 to 67) with the ratio of male to female patients being 1.5:1. The most common site of the tumour was the femur (n = 103) followed by tibia (n = 66). The vascular proximity was categorized based on the preoperative MRI after neoadjuvant chemotherapy into four types: type 1 > 5 mm; type 2 ≤ 5 mm, > 0 mm; type 3 attached; type 4 surrounded.

Results

Limb salvage rate based on the proximity type was 92%, 88%, 51%, and 0% for types 1 to 4, respectively, and the overall survival at five years was 82%, 77%, 57%, and 67%, respectively (p < 0.001). Local recurrence rate in patients with limb-salvage surgery was 7%, 8%, and 22% for the types 1 to 3, respectively (p = 0.041), and local recurrence at the perivascular area was observed in 1% and 4% for type 2 and 3, respectively. The mean microscopic margin to the major vessels was 6.9 mm, 3.0 mm, and 1.4 mm for types 1 to 3, respectively. In type 3, local recurrence-free survival with limb salvage was significantly poorer compared with amputation (p = 0.025), while the latter offered no overall survival benefit. In this group of patients, factors such as good response to chemotherapy or limited vascular attachment to less than half circumference or longitudinal 10 mm reduced the risk of local recurrence.

Conclusion

The proximity of osteosarcoma to major blood vessels is a poor prognostic factor for local control and survival. Amputation offers better local control for tumours attached to the blood vessels but does not improve survival. Limb salvage surgery offers similar local control if the tumour attachment to blood vessels is limited. Cite this article: Bone Joint J 2019;101-B:1024–1031.

Is there a role for chemotherapy after local relapse in high-grade osteosarcoma?

BACKGROUND

High-grade bone osteosarcoma has a high relapse rate. The best treatment of local recurrence (LR) is under discussion. The aim of this study is to analyze LR patterns and factors prognostic for survival.

METHODS

LR diagnostic modality (clinical or imaging), pattern of recurrence, and post-LR survival (PLRS) were assessed.

RESULTS

Sixty-two patients were identified, with median age 21 years (range, 9-75 years), including 11 (18%) ≤15 years, 30 (48%) from 16 to 29 years; 21 (34%) were older. Patterns of relapse were LR only 58%, LR + distant metastases (DM) 42%. Seventy-nine percent of patients relapsed within 24 months, and diagnosis was clinical in 88%. LR treatment was surgery 85%, chemotherapy 55%, chemotherapy + surgery 45%. Surgical complete remission after LR (CR2) was achieved in 60% (LR 86%; LR + DM 23%). With a median follow-up of 43 months (range, 5-235 months), the five-year PLRS was 37%, significantly better for patients with longer LR-free interval (LRFI; ≤24 months 31% vs > 24 months 61.5%, P = 0.03), absence of DM (no DM 56% vs DM 11.5%, P = 0.0001), and achievement of CR2 (no CR2 0% vs CR2 58.5%, P = 0.0001). No difference was found according to age and chemotherapy (LR only: five-year PLRS: 53% without chemotherapy vs 58% with chemotherapy, P = 0.9; LR + DM: five-year PLRS: 25% without chemotherapy vs 9% with chemotherapy, P = 0.7).

CONCLUSIONS

Early relapse is detected by symptoms in 90% of cases and associated with worse outcome. The achievement of CR2, not age, is crucial for survival. For patients with LR only, better survival was demonstrated, as compared with DM, and no improvement with chemotherapy after surgery was found.

MRI Identification of the Osseous Extent of Pediatric Bone Sarcomas

BACKGROUND

The quantitative accuracy of MRI in predicting the intraosseous extent of primary sarcoma of bone has not been definitively confirmed, although MRI is widely accepted as an accurate tool to plan limb salvage resections. Because inaccuracies in MRI determination of tumor extent could affect the ability of a tumor surgeon to achieve negative margins and avoid local recurrence, we thought it important to assess the accuracy of MR-determined tumor extent to the actual extent observed pathologically from resected specimens in pediatric patients treated for primary sarcomas of bone.

QUESTIONS/PURPOSES

(1) Does the quantitative pathologic bony margin correlate with that measured on preoperative MRI? (2) Are T1- or T2-weighted MRIs most accurate in determining a margin? (3) Is there a difference in predicting tumor extent between MRI obtained before or after neoadjuvant chemotherapy and which is most accurate?

METHODS

We retrospectively studied a population of 211 potentially eligible patients who were treated with limb salvage surgery between August 1999 and July 2015 by a single surgeon at a single institution for primary sarcoma of bone. Of 131 patients (62%) with disease involving the femur or tibia, 107 (51%) were classified with Ewing's sarcoma or osteosarcoma. Records were available for review in our online database for 79 eligible patients (37%). Twenty-six patients (12%) were excluded because of insufficient or unavailable clinical or pathology data and 17 patients (8%) were excluded as a result of inadequate or incomplete MR imaging, leaving 55 eligible participants (26%) in the final cohort. The length of the resected specimen was superimposed on preresection MRI sequences to compare the margin measured by MRI with the margin measured by histopathology. Arithmetic mean differences and Pearson r correlations were used to assess quantitative accuracy (size of the margin).

RESULTS

All MR imaging types were positively associated with final histopathologic margin. T1-weighted MRI after neoadjuvant chemotherapy and final histopathologic margin had the strongest positive correlation of all MR imaging and time point comparisons (r = 0.846, p < 0.001). Mean differences existed between the normal marrow margin on T1-weighted MRI before neoadjuvant chemotherapy (t = 8.363; mean, 18.883 mm; 95% confidence interval [CI], 14.327-23.441; p < 0.001), T2-weighted MRI before neoadjuvant chemotherapy (t = 8.194; mean, 17.204 mm; 95% CI, 12.970-21.439; p < 0.001), T1-weighted after neoadjuvant chemotherapy (t = 10.808; mean, 22.178 mm; 95% CI, 18.042-26.313; p < 0.001), T2-weighted after neoadjuvant chemotherapy (t = 10.702; mean, 20.778 mm; 95% CI, 16.865-24.691; p < 0.001), and the final histopathologic margin. T1-weighted MRI after neoadjuvant chemotherapy compared with the final histopathologic margin had the smallest mean difference in MRI-measured versus histopathologic margin size (mean, 5.9 mm; SD = 4.5 mm).

CONCLUSIONS

T1 MRI after neoadjuvant chemotherapy exhibited the strongest positive correlation and smallest mean difference compared with histopathologic margin. When planning surgical resections based on MRI obtained after neoadjuvant chemotherapy, for safety, one should account for a potential difference between the apparent margin of a tumor on an MRI and the actual pathologic margin of that tumor of up to 1 cm.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Can Navigation-assisted Surgery Help Achieve Negative Margins in Resection of Pelvic and Sacral Tumors?

BACKGROUND

Navigation-assisted resection has been proposed as a useful adjunct to resection of malignant tumors in difficult anatomic sites such as the pelvis and sacrum where it is difficult to achieve tumor-free margins. Most of these studies are case reports or small case series, but these reports have been extremely promising. Very few reports, however, have documented benefits of navigation-assisted resection in series of pelvic and sacral primary tumors. Because this technology may add time and expense to the surgical procedure, it is important to determine whether navigation provides any such benefits or simply adds cost and time to an already complex procedure.

QUESTIONS/PURPOSES

(1) What proportion of pelvic and sacral bone sarcoma resections utilizing a computer-assisted resection technique achieves negative margins? (2) What are the oncologic outcomes associated with computer-assisted resection of pelvic and sacral bone sarcomas? (3) What complications are associated with navigation-assisted resection?

METHODS

Between 2009 and 2015 we performed 24 navigation-assisted resections of primary tumors of the pelvis or sacrum. Of those, four were lost to followup after the 2-year postoperative visit. In one patient, however, there was a failure of navigation as a result of inadequate imaging, so nonnavigated resection was performed; the remaining 23 were accounted for and were studied here at a mean of 27 months after surgery (range, 12-52 months). During this period, we performed navigation-assisted resections in all patients presenting with a pelvis or sacral tumor; there was no selection process. No patients were treated for primary tumors in these locations without navigation during this time with the exception of the single patient in whom the navigation system failed. We retrospectively evaluated the records of these 23 patients and evaluated the margin status of these resections. We calculated the proportion of patients with local recurrence, development of metastases, and overall survival at an average 27-month followup (range, 12-52 months). We queried a longitudinally maintained surgical database for any complications and noted which, if any, could have been directly related to the use of the navigation-assisted technique.

RESULTS

In our series, 21 of 23 patients had a negative margin resection. In all patients the bone margin was negative, but two with sacral resections had positive soft tissue margins. Six of 23 patients experienced local recurrence within the study period. Three patients died during the study period. Seventeen patients demonstrated no evidence of disease at last recorded followup. We noted three intraoperative complications: one dural tear, one iliac vein laceration, and one bladder injury. Eight patients out of 23 had wound complications resulting in operative débridement. Two patients in the series developed transient postoperative femoral nerve palsy, which we believe were caused by stretch of the femoral nerve secondary to the placement of the reference array in the pubic ramus.

CONCLUSIONS

Navigation-assisted resection of pelvic and sacral tumors resulted in a high likelihood of negative margin resection in this series, and we observed relatively few complications related specifically to the navigation. We have no comparison group without navigation, and future studies should indeed compare navigated with nonnavigated resection approaches in these anatomic locations. We did identify a potential navigation-related complication of femoral nerve palsy in this series and suggest careful placement and observation of the reference array during the operative procedure to lessen the likelihood of this previously unreported complication. We suggest it is worthwhile to consider the use of navigation-assisted surgery in resection of tumors of the pelvis and sacrum, but further study will be needed to determine its precise impact, if any, on local recurrence and other oncologic outcomes.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

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.

Pathological fractures in predicting clinical outcomes for patients with osteosarcoma

Background

Studies reported contradictory results for the prognostic significance of a pathological fracture in osteosarcoma patients. The aim of this study is to report the outcomes for a cohort of patients with osteosarcoma who presented with and without pathological fractures and to identify the prognostic importance of pathological fracture in predicting outcomes and influences on survival.

Methods

Data of patients with osteosarcoma were retrospectively reviewed. Between March 1992 and June 2014, a total of 268 patients with osteosarcoma were included in this analysis, of whom 34 (12.7%) with fractures at diagnosis or sustained after chemotherapy and 234 (87.3%) without fracture. All patients were treated with approaches that integrated chemotherapy and surgical resections to maximal extent of all sites whenever feasible. The association between potential prognostic factors and survival for these patients were analyzed and compared.

Results

No significant difference was observed in overall survival, progression free survival, and disease free survival between osteosarcoma patients with pathological fractures and without fracture. The patients without fracture had a 5-year survival of 50% and 10-year survival of 21%, in contrast to 37% (5-year) and 22% (10-year) in patients with fractures. Lung metastasis was the significant predictor for the presence of fractures. Advanced stage (III) of tumor, lung metastasis, poor response to chemotherapy, and local recurrence were associated increased risk for death in all osteosarcoma patients.

Conclusion

Pathological fracture is not a predictor of worse survival in this study. Further studies with matched cases are needed to confirm our observations.

Tumoral calcinosis mimicking recurrent osteosarcoma

We report a case of a tumoral calcinosis mimicking the appearance of recurrent osteosarcoma of the left femur and tibia in a 29-year-old woman with a history of osteosarcoma and chronic renal failure. Both processes can appear radiographically and histologically similar. Due to loosening of the orthopedic hardware, our patient underwent surgical revision and biopsy. We review the imaging appearances of both entities as well as the underlying mechanism of tumoral calcinosis secondary to renal disease. We also discuss how PET and CT imaging can aid in differentiation of these processes and possibly prevent surgical biopsy in other cases.

What are the factors that affect survival and relapse after local recurrence of osteosarcoma?

BACKGROUND

Despite improvements in treatment of primary osteosarcoma, treatment of patients who have local recurrence is not well defined.

QUESTIONS/PURPOSES

We asked: (1) What are the 5- and 10-year overall survival rates of patients with osteosarcoma who have a local recurrence? (2) What factors are associated with better survival after a local recurrence? (3) Does chemotherapy affect overall survival after local recurrence? (4) What are the rates of rerecurrence after amputation and with limb salvage?

METHODS

We reviewed 45 patients with nonmetastatic conventional high-grade osteosarcoma who had local recurrence between 1985 and 2007, during which time 461 patients were treated for the same disease. Seven patients with known local recurrence were lost to followup and not included in our study. The median age of the patients was 18 years, and minimum followup was 2 months (median, 39 months; range, 2-350 months). The primary tumor was located in the extremity in 36 patients and the pelvis in nine. The median time from initial surgery for resection or amputation of the primary tumor to local recurrence was 18 months (range, 2-149 months). Ten recurrences developed in bone and 35 in soft tissue. In 21 of the latter cases, the soft tissue recurrence was undetectable on conventional radiographs. Prognostic factors for overall patient survival after recurrence were evaluated by Kaplan-Meier survival and Cox multivariate analyses.

RESULTS

Overall postrecurrence patient survival was 30% at 5 years and 13% at 10 years. Cox multivariate analysis revealed that concurrent metastasis (relative risk = 4, p = 0.003) and recurrent tumor size 5 cm or larger (relative risk = 13, p < 0.0001) were independent predictors of worse survival. With the numbers available, treatment with chemotherapy after local recurrence was not associated with better survival (p = 0.54). Nine patients had a second local recurrence, and the actuarial risk of rerecurrence was 34% at 5 years. There was no difference in the frequency of rerecurrence between patients treated by amputation and wide local excision (p = 0.23).

CONCLUSIONS

The long-term prognosis of patients who have local recurrence of osteosarcoma is poor. Followup beyond 5 years is essential, because the disease can have a protracted course. Most recurrences develop in soft tissue and are difficult to see on plain radiographs alone. The size of the recurrence and presence of metastasis were independent prognostic factors, suggesting that early detection may be important. Chemotherapy did not have a significant effect on survival, and surgical eradication of recurrence with wide margins may be critical to maximizing the chances for survival.

Management of local recurrence of pediatric osteosarcoma following limb-sparing surgery

BACKGROUND

The optimal management of locally recurrent pediatric osteosarcoma is not established, especially after prior limb-sparing surgery. We describe our experience in the management of these patients and identify prognostic indicators of post-recurrence survival.

METHODS

We conducted a retrospective, single-institution review of patients with locally recurrent osteosarcoma after limb-salvage surgery who were treated between October 1989 and January 2012. The management of each recurrence was evaluated, and patient, disease, and treatment factors were correlated with post-recurrence survival (PRS).

RESULTS

Of 200 patients who underwent limb-sparing procedures, 18 (9 %) had biopsy-proven local recurrence. Recurrences occurred in soft tissue in 15 patients (83.3 %). Six patients (33.3 %) were amenable to repeat limb-sparing surgery. Median time to local recurrence was 1.4 (range 0.6-10.4) years. Median PRS was 11.8 months (range 3.7 months-12.1 years). Post-recurrence survival was significantly associated with the length of resection margins and was longer when recurrent tumors were resected with margins of ≥1 cm, compared with subcentimeter or positive margins (P = 0.03). Median PRS was longer in patients who underwent amputations (2.44 years) than those who underwent repeat limb-sparing surgery (0.86 years), and in patients who had distant metastases resected (2.7 years) than those who did not (0.85 years); however, differences were not significant.

CONCLUSIONS

Local management of recurrent osteosarcoma in a previously reconstructed limb is highly individualized. A sufficiently wide resection is important for local control of recurrences, independent of the type of surgery. Maintaining control of distant metastases may also contribute to improved survival.

Review of management issues in relapsed osteosarcoma

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. With combined modality treatment long-term survival rate for localized disease is near 70%. Thirty percent of patients relapse with lung as the commonest site. Surgery is the treatment of choice for relapsed patients whenever possible. Addition of chemotherapy to surgery provides survival benefit in patients not achieving second surgical remission. Even patients with multiple lung recurrences can be cured with repeated thoracotomies. Disease-free interval and complete surgical resection are the main prognostic factor for post-relapse survival.

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

BACKGROUND

The relationship between surgical margin and local recurrence (LR) in osteosarcoma patients with poor responses to chemotherapy is unclear. Moreover, the incidences of LR according to three different resection planes (bone, soft tissue, and perineurovascular) are not commonly known.

METHODS

We evaluated the incidence of LR in three areas. To assess whether there is a role of surgical margin on LR in patients resistant to preoperative chemotherapy, we designed a case (35 patients with LR) and control (70 patients without LR) study. Controls were matched for age, location, initial tumor volume, and tumor volume change during preoperative chemotherapy.

RESULTS

LR occurred at the soft tissues in 18 cases (51.4%), at the perineurovascular tissues in 11 cases (31.4%), and at the bones in six cases (17.2%). The proportion of inadequate perineurovascular margin was higher in the case group than in the control group (p = 0.01). Within case-control group (105 patients), a correlation between each margin status and LR at corresponding area was found in the bone (p < 0.001) and perineurovascular area (p = 0.001).

CONCLUSIONS

LR is most common in soft tissues. In patients showing similar unfavorable responses to chemotherapy, the losses of perineurovascular fat plane on preoperative magnetic resonance imaging may be a valuable finding in predicting LR.

Prevention of contamination by biopsy needle track contamination using a novel adriamycin-loaded gelatin sponge

Background

The gold standard of tumor diagnosis is histological examination of a biopsy; however, there is concern that tumor cell dissemination along the needle track during percutaneous biopsy can cause local tumor relapse. We aimed to evaluate the value of an adriamycin (ADM)-loaded gelatin sponge in preventing tumor cell contamination along the biopsy needle track.

Methods

Data were obtained from 40 patients who were diagnosed by core needle biopsy as having osteosarcoma and who were followed up at our hospital between 2008 and 2011. Of the 40 patients, 20 had the needle biopsy tracks filled with ADM-loaded absorbable gelatin sponge immediately after the biopsy specimen was obtained, while the other 20 did not. All 40 patients underwent limb-salvage surgery, and specimens were obtained from the biopsy track for histopathologic examination of multiple sections.

Results

On histological examination, there was less tumor cell contamination along the biopsy tracks in the ADM group.

Conclusion

Use of ADM-loaded absorbable gelatin sponge may prevent tumor cell contamination of a biopsy track, and reduce the possibility of consequent tumor relapse.

Surgical technique: Computer-generated custom jigs improve accuracy of wide resection of bone tumors

BACKGROUND

Manual techniques of reproducing a preoperative plan for primary bone tumor resection using rudimentary devices and imprecise localization techniques can result in compromised margins or unnecessary removal of unaffected tissue. We examined whether a novel technique using computer-generated custom jigs more accurately reproduces a preoperative resection plan than a standard manual technique.

DESCRIPTION OF TECHNIQUE

Using CT images and advanced imaging, reverse engineering, and computer-assisted design software, custom jigs were designed to precisely conform to a specific location on the surface of partially skeletonized cadaveric femurs. The jigs were used to perform a hemimetaphyseal resection.

METHODS

We performed CT scans on six matched pairs of cadaveric femurs. Based on a primary bone sarcoma model, a joint-sparing, hemimetaphyseal wide resection was precisely outlined on each femur. For each pair, the resection was performed using the standard manual technique on one specimen and the custom jig-assisted technique on the other. Superimposition of preoperative and postresection images enabled quantitative analysis of resection accuracy.

RESULTS

The mean maximum deviation from the preoperative plan was 9.0 mm for the manual group and 2.0 mm for the custom-jig group. The percentages of times the maximum deviation was greater than 3 mm and greater than 4 mm was 100% and 72% for the manual group and 5.6% and 0.0% for the custom-jig group, respectively.

CONCLUSIONS

Our findings suggest that custom-jig technology substantially improves the accuracy of primary bone tumor resection, enabling a surgeon to reproduce a given preoperative plan reliably and consistently.

Epidemiology and therapies for metastatic sarcoma

Sarcomas are cancers arising from the mesenchymal layer that affect children, adolescents, young adults, and adults. Although most sarcomas are localized, many display a remarkable predilection for metastasis to the lungs, liver, bones, subcutaneous tissue, and lymph nodes. Additionally, many sarcoma patients presenting initially with localized disease may relapse at metastatic sites. While localized sarcomas can often be cured through surgery and often radiation, controversies exist over optimal management of patients with metastatic sarcoma. Combinations of chemotherapy are the most effective in many settings, and many promising new agents are under active investigation or are being explored in preclinical models. Metastatic sarcomas are excellent candidates for novel approaches with additional agents as they have demonstrated chemosensitivity and affect a portion of the population that is motivated toward curative therapy. In this paper, we provide an overview on the common sarcomas of childhood (rhabdomyosarcoma), adolescence, and young adults (osteosarcoma, Ewing sarcoma, synovial sarcoma, and malignant peripheral nerve sheath tumor) and older adults (leiomyosarcoma, liposarcoma, and undifferentiated high grade sarcoma) in terms of the epidemiology, current therapy, promising therapeutic directions and outcome with a focus on metastatic disease. Potential advances in terms of promising therapy and biologic insights may lead to more effective and safer therapies; however, more clinical trials and research are needed for patients with metastatic sarcoma.

Haptic robot-assisted surgery improves accuracy of wide resection of bone tumors: a pilot study

BACKGROUND

Accurate reproduction of the preoperative plan at the time of surgery is critical for wide resection of primary bone tumors. Robotic technology can potentially help the surgeon reproduce a given preoperative plan, but yielding control of cutting instruments to a robot introduces potentially serious complications. We developed a novel passive ("haptics") robot-assisted resection technique for primary bone sarcomas that takes advantage of robotic accuracy while still leaving control of the cutting instrument in the hands of the surgeon.

QUESTIONS/PURPOSES

We asked whether this technique would enable a preoperative resection plan to be reproduced more accurately than a standard manual technique.

METHODS

A joint-sparing hemimetaphyseal resection was precisely outlined on the three-dimensionally reconstructed image of a representative Sawbones femur. The indicated resection was performed on 12 Sawbones specimens using the standard manual technique on six specimens and the haptic robotic technique on six specimens. Postresection images were quantitatively analyzed to determine the accuracy of the resections compared to the preoperative plan, which included measuring the maximum linear deviation of the cuts from the preoperative plan and the angular deviation of the resection planes from the target planes.

RESULTS

Compared with the manual technique, the robotic technique resulted in a mean improvement of 7.8 mm of maximum linear deviation from the preoperative plan and 7.9° improvement in pitch and 4.6° improvement in roll for the angular deviation from the target planes.

CONCLUSIONS

The haptic robot-assisted technique improved the accuracy of simulated wide resections of bone tumors compared with manual techniques.

CLINICAL RELEVANCE

Haptic robot-assisted technology has the potential to enhance primary bone tumor resection. Further bench and clinical studies, including comparisons with recently introduced computer navigation technology, are warranted.

The Current and Future Therapies for Human Osteosarcoma

Osteosarcoma (OS) is the most common non-hematologic malignant tumor of bone in adults and children. As sarcomas are more common in adolescents and young adults than most other forms of cancer, there are a significant number of years of life lost secondary to these malignancies. OS is associated with a poor prognosis secondary to a high grade at presentation, resistance to chemotherapy and a propensity to metastasize to the lungs. Current OS management involves both chemotherapy and surgery. The incorporation of cytotoxic chemotherapy into therapeutic regimens escalated cure rates from <20% to current levels of 65-75%. Furthermore, limb-salvage surgery is now offered to the majority of OS patients. Despite advances in chemotherapy and surgical techniques over the past three decades, there has been stagnation in patient survival outcome improvement, especially in patients with metastatic OS. Thus, there is a critical need to identify novel and directed therapy for OS. Several Phase I trials for sarcoma therapies currently ongoing or recently completed have shown objective responses in OS. Novel drug delivery mechanisms are currently under phase II and III clinical trials. Furthermore, there is an abundance of preclinical research which holds great promise in the development of future OS-directed therapeutics. Our continuously improving knowledge of the molecular and cell-signaling pathways involved in OS will translate into more effective therapies for OS and ultimately improved patient survival. The present review will provide an overview of current therapies, ongoing clinical trials and therapeutic targets under investigation for OS.

Current concepts in surgical treatment of osteosarcoma

Osteosarcoma is the most common malignant primary neoplasm of bone. For an optimal oncological outcome, surgical removal of tumor is an essential component of its multidisciplinary treatment. Limb salvage surgery has long been established as the standard of care for osteosarcoma. While limb-salvaging techniques have acceptable rates of disease control, amputation remains a valid procedure in selected cases. In current orthopedic oncology practice, the focus is on optimizing the balance between preservation of form and function of the limb and adequate oncological clearance at the same time. Improving the functional outcome and longevity of reconstructive procedures also remains a challenge.

Local recurrence has only a small effect on survival in high-risk extremity osteosarcoma

BACKGROUND

Tumor enlargement after chemotherapy is considered one of the high-risk factors for local recurrence and survival in osteosarcoma. We hypothesized patients with this risk factor will have similar survival regardless of the development of local recurrence.

QUESTIONS/PURPOSES

We asked (1) the prognostic factors for survival in our cohort, (2) how much effect local recurrence has on survival among patients with similar preoperative risk factors, and (3) what prognostic factors are important for survival in these selected patients.

METHODS

We analyzed the prognostic factors for survival in 449 patients with extremity osteosarcoma without metastatic disease at initial diagnosis and treatment (38 with local recurrence, 411 without local recurrence). We compared the survival difference between patients with local recurrence (n = 38) and without local recurrence (control, n = 76) matched for age, location, initial tumor volume, and tumor volume change after chemotherapy, and assessed prognostic factors in this subgroup.

RESULTS

In a cohort study, multivariate analysis revealed initial tumor volume, tumor enlargement, inadequate margin, and local recurrence predicted poor survival. In the case-control study, the 10-year metastasis-free survival rates of two groups were 13.1 ± 10.7% and 19.3 ± 9%, respectively. In the case-controlled groups, tumor enlargement and initial tumor volume showed multivariate significance.

CONCLUSIONS

Local recurrence has a small impact on survival in patients with high-risk osteosarcoma.

LEVEL OF EVIDENCE

Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Tumor volume increase during preoperative chemotherapy as a novel predictor of local recurrence in extremity osteosarcoma

BACKGROUND

Known risk factors (surgical margin, tumor necrosis) of local recurrence (LR) in osteosarcoma are determined by results available after surgery. However, relations between preoperative characteristics and LR have not been clearly defined.

METHODS

We compared the clinicopathologic characteristics of 36 osteosarcoma patients with LR and 394 patients without LR after surgery. In addition, prognostic variables were evaluated to establish factors could influence LR.

RESULTS

Compared to the non-LR group, the LR group showed an increase in tumor volume ratio (TVR) during preoperative chemotherapy (P < 0.01), inadequate surgical margin (P < 0.01), and poor histologic response (P < 0.01). Univariate analysis of data from 430 patients revealed that an increased TVR (P < 0.01), inadequate surgical margin (P < 0.01), poor histologic response (P < 0.01), and nonosteoblastic pathologic subtype (P = 0.04) were negatively related to LR-free survival. In multivariate analysis, an elevated TVR (P < 0.01, relative risk = 10.26) and inadequate surgical margin (P < 0.01, relative risk = 5.91) emerged as the key prognostic factors for LR.

CONCLUSIONS

A TVR increase during preoperative chemotherapy could be used to predict patients at high risk of LR. This finding might be useful when considering surgical options to decrease the risk of LR.

Malignant and metastatic tumors of the hand

Malignant tumors of the hand are rare, although there remain many instances in which marginal excisions are performed for unsuspected malignant hand lesions. Suboptimal biopsy incisions and inadvertent contamination during these excisions may result in larger resections or amputations being necessary to ensure complete removal of the tumor with negative margins. This article provides an update for the current management of patients with primary malignant and metastatic tumors of the hand, including the roles of adjuvant radiotherapy and chemotherapy for the more common hand tumors.

Runx2, p53, and pRB status as diagnostic parameters for deregulation of osteoblast growth and differentiation in a new pre-chemotherapeutic osteosarcoma cell line (OS1)

Osteosarcomas are the most prevalent primary bone tumors found in pediatric patients. To understand their molecular etiology, cell culture models are used to define disease mechanisms under controlled conditions. Many osteosarcoma cell lines (e.g., SAOS-2, U2OS, MG63) are derived from Caucasian patients. However, patients exhibit individual and ethnic differences in their responsiveness to irradiation and chemotherapy. This motivated the establishment of osteosarcoma cell lines (OS1, OS2, OS3) from three ethnically Chinese patients. OS1 cells, derived from a pre-chemotherapeutic tumor in the femur of a 6-year-old female, were examined for molecular markers characteristic for osteoblasts, stem cells, and cell cycle control by immunohistochemistry, reverse transcriptase-PCR, Western blotting and flow cytometry. OS1 have aberrant G-banded karyotypes, possibly reflecting chromosomal abnormalities related to p53 deficiency. OS1 had ossification profiles similar to human fetal osteoblasts rather than SAOS-2 which ossifies ab initio (P < 0.05). Absence of p53 correlates with increased Runx2 expression, while the slow proliferation of OS1 cells is perhaps attenuated by pRB retention. OS1 express mesenchymal stem cell markers (CD44, CD105) and differ in relative expression of CD29, CD63, and CD71 to SAOS-2. (P < 0.05). Cell cycle synchronization with nocodazole did not affect Runx2 and CDK1 levels but decreased cyclin-E and increased cyclin-A (P < 0.05). Xenotransplantion of OS1 in SCID mice yields spontaneous tumors that were larger and grew faster than SAOS-2 transplants. Hence, OS1 is a new osteosarcoma cell culture model derived from a pre-chemotherapeutic ethnic Chinese patient, for mechanistic studies and development of therapeutic strategies to counteract metastasis and deregulation of mesenchymal development.

Surgical management of primary osteosarcoma

Surgical strategies for the primary tumor for patients with extremity and pelvis osteosarcoma have evolved from the ablative to limb-sparing approaches over the past three decades. Favorable oncologic and functional outcomes with contemporary tissue-conserving techniques consistently observed in skeletally mature patients have prompted the application of similar approaches to a growing number of eligible skeletally immature patients. In response to emerging long-term outcome data, current strategies have focused principally on refining the nature and scope of surgical resection to preserve uninvolved tissues, and on the adoption of novel biological and nonbiological skeletal and soft-tissue reconstruction methods to optimize function. We focus on these clinical issues and discuss current efforts to advance the surgical management of the primary tumor and address the limitations of the definitive treatment of the primary tumor, including locally recurrent disease and complications of skeletal reconstructions.

Osteosarcoma: review of the past, impact on the future. The American experience

Major advances have been achieved in the treatment of osteosarcoma with the discovery of several chemotherapeutic agents that were active in the disease. These agents comprise high-dose methotrexate with leucovorin rescue, Adriamycin, cisplatin, ifosfamide and cyclophosphamide. The agents were integrated into various regimens and administered in an effort to destroy silent pulmonary micrometastases which are considered to be present in at least 80% of patients at the time of diagnosis. Their efficacy in achieving this goal was realized and their use was further extended to the application of preoperative (neoadjuvant) chemotherapy to destroy the primary tumor and achieve safe surgical resections. Disease free survival was escalated from <20% prior to the introduction of effective chemotherapy to 55-75% and overall survival to 85%. Further, the opportunity to perform limb salvage was expanded to 80% of patients. Of interest also was an attempt in one series to treat the primary tumor exclusively with chemotherapy, and abrogation of surgery. Adding to these advances, varieties of subsequently discovered agents are currently undergoing investigations in patients who have relapsed and/or failed conventional therapy. The agents include Gemcitabine, Docetaxel, novel antifolate compounds, and a liposome formulation of adriamycin (Doxil). A biological agent, muramyl tripeptide phosphatidyl ethanolamine (MTPPE) was also recently investigated in a 2x2 factorial design to determine its efficacy in combination with chemotherapy (methotrexate, cisplatin, Adriamycin and ifosfamide).In circumstances where the tumor was considered inoperable, chemotherapy and radiotherapy were advocated for local control. High dose methotrexate, Adriamycin and cisplatin and Gemcitabine interact with radiation therapy and potentiate its therapeutic effect. This combination is also particularly useful in palliation. Occasionally, the combination of radiation and chemotherapy may render a tumor suitable for surgical ablation. Samarium153, a radio active agent, is also used as palliative therapy for bone metastases.However, despite the advances achieved with the multidisciplinary application of chemotherapy, radiotherapy and surgical ablation of the primary tumor over the past 3(1/2) decades, the improved cure rate reported initially has not altered. Particularly vexing is the problem of rescuing patients who develop pulmonary metastases after receiving seemingly effective multidisciplinary treatment. Approximately 15-25% of such patients only are rendered free of disease with the reintroduction of chemotherapy and resection of metastases. Extrapulmonary metastases and multifocal osteosarcoma also constitute a major problem. The arsenal of available agents to treat such patients has not made any substantial impact in improving their survival. New chemotherapeutic agents are urgently required to improve treatment and outcome. Additional strategies to be considered are targeted tumor therapy, anti tumor angiogenesis, biotherapy and therapy based upon molecular profiles. This communication outlines sequential discoveries in the chemotherapeutic research of osteosarcoma in the United States of America. It also describes the principles regulating the therapeutic application of the regimens and considers the impact of their results on the conduct in the design of future investigations and treatment.

Therapy for osteosarcoma: where do we go from here?

Osteosarcoma is the most common malignant primary bone tumor in children and adolescents. Current optimal treatment for osteosarcoma consists of multi-agent chemotherapy and aggressive surgical resection of all sites of disease involvement. The current national and international cooperative trial for patients with newly diagnosed osteosarcoma builds upon the backbone of cisplatin, doxorubicin, and methotrexate. This protocol is designed to clarify whether (i) the addition of ifosfamide and etoposide to postoperative chemotherapy with cisplatin, doxorubicin, and methotrexate improves the event-free survival and overall survival for patients with resectable osteosarcoma and a poor histologic response to 10 weeks of preoperative chemotherapy; and (ii) the addition of pegylated interferon-alpha-2b as maintenance therapy after postoperative chemotherapy with cisplatin, doxorubicin, and methotrexate improves the event-free survival and overall survival for patients with resectable osteosarcoma and a good histologic response to 10 weeks of preoperative chemotherapy. However, the optimal treatment strategy (or strategies) for patients with relapsed or metastatic disease has yet to be defined. This remains one of the persistent challenges in the treatment of osteosarcoma. Recent therapeutic advances have focused on circumventing chemotherapy resistance mechanisms, incorporation of non-classical agents into upfront therapy, targeting of the tumor micro-environment, and investigating the role of novel delivery mechanisms. In patients with localized disease the 5-year survival rate is at least 70%; patients with metastatic or recurrent disease have <20% chance of long-term survival despite aggressive therapies. These figures have changed little in the past 2 decades. This review focuses on the current therapy for osteosarcoma, and highlights emerging strategies that will hopefully change the outlook for patients with this disease.

A review of clinical and molecular prognostic factors in osteosarcoma

Traditional prognostic determinants in osteosarcoma have included demographics (age, sex), tumour size, site, stage, and the response to chemotherapy. Many of these are determined using varying techniques and units of measurement, which can make comparison between studies difficult. The absence of survival difference between limb sparing surgery and amputation has been repeatedly demonstrated in primary disease, and even in the setting of pathological fracture. On the other hand, there is still some controversy over the existence of increased local recurrence for limb-sparing surgery, and the implications of this. Commonly used prognostic determinants such as metastases, and response to chemotherapy enable a high degree of prognostic accuracy but usually at a late stage in the course of disease. Leading on from this, there is a need to uncover molecular pathways with specific influence over osteosarcoma progression to facilitate earlier treatment changes. Some important pathways are already being defined, for example the association of CXCR4 with metastases on presentation, the likelihood of doxorubicin resistance with positive P-glycoprotein, and the reduced survival prediction of over expressed survivin. It is anticipated that the future of osteosarcoma treatment will involve treatment tailored to the molecular profile of tumours at diagnosis, adjuvant therapy directed towards dysfunctional molecular pathways rather than the use of cytotoxics, and a more standardised approach to the measurement of clinical prognostic factors.