Osteosarcomas With Few Chromosomal Alterations or Adult Onset Are Genetically Heterogeneous.

Osteosarcoma is the most common primary bone malignancy, often detected in children and adolescents and commonly associated with TP53 alterations along with a high number of chromosomal rearrangements. However, osteosarcoma can affect patients of any age, and some tumors display less genetic complexity. Besides TP53 variants, data on key driving mutations are lacking for many osteosarcomas, particularly those affecting adults. To detect osteosarcoma-specific alterations, we screened transcriptomic and genomic sequencing and copy number data from 150 bone tumors originally diagnosed as osteosarcomas. To increase the precision in gene fusion detection, we developed a bioinformatic tool denoted as NAFuse, which extracts gene fusions that are verified at both the genomic and transcriptomic levels. Apart from the already reported genetic subgroups of osteosarcoma with TP53 structural variants, or MDM2 and/or CDK4 amplification, we did not identify any recurrent genetic driver that signifies the remaining cases. Among the plethora of mutations identified, we found genetic alterations characteristic of, or similar to, those of other bone and soft tissue tumors in 8 cases. These mutations were found in tumors with relatively few other genetic alterations or in adults. Due to the lack of clinical context and available tissue, we can question the diagnosis only on a genetic basis. However, our findings support the notion that osteosarcomas with few chromosomal alterations or adult onset seem genetically distinct from conventional osteosarcomas of children and adolescents.

Disruption of the TP53 locus in osteosarcoma leads to TP53 promoter gene fusions and restoration of parts of the TP53 signalling pathway.

TP53 is the most frequently mutated gene in human cancer. This gene shows not only loss-of-function mutations but also recurrent missense mutations with gain-of-function activity. We have studied the primary bone malignancy osteosarcoma, which harbours one of the most rearranged genomes of all cancers. This is odd since it primarily affects children and adolescents who have not lived the long life thought necessary to accumulate massive numbers of mutations. In osteosarcoma, TP53 is often disrupted by structural variants. Here, we show through combined whole-genome and transcriptome analyses of 148 osteosarcomas that TP53 structural variants commonly result in loss of coding parts of the gene while simultaneously preserving and relocating the promoter region. The transferred TP53 promoter region is fused to genes previously implicated in cancer development. Paradoxically, these erroneously upregulated genes are significantly associated with the TP53 signalling pathway itself. This suggests that while the classical tumour suppressor activities of TP53 are lost, certain parts of the TP53 signalling pathway that are necessary for cancer cell survival and proliferation are retained. In line with this, our data suggest that transposition of the TP53 promoter is an early event that allows for a new normal state of genome-wide rearrangements in osteosarcoma. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Intralesional margin after excision of a high-grade osteosarcoma: Is it a catastrophe?

BACKGROUND AND OBJECTIVES: Treatment of high-grade osteosarcoma (OS) relies on a combination of systemic chemotherapy and radical surgical excision of the tumor. Little is known on what happens in case of an irrefutably inadequate (intralesional) margin. We aimed to describe the outcome of patients with high-grade OSs of the trunk and the extremities where planned wide resection resulted in an intralesional margin. METHODS: A retrospective study from the Scandinavian Sarcoma Group registry and the Royal Orthopaedic Hospital databases including data from 53 patients surgically treated between the years 1990 and 2017. RESULTS: Local recurrence was observed in 13/53 patients. All patients with local recurrence where the neoadjuvant chemotherapy response could be retrieved (n = 9) were shown to be poor responders. None of the patients with good response to chemotherapy relapsed. Postoperative radiotherapy was not associated with improved local control of the disease. Re-excision surgery was performed in only seven patients, and two of them had tumor relapse. CONCLUSIONS: Good response to chemotherapy salvages the outcome of surgical excision with a poor margin in patients with high-grade OSs and a watchful waiting strategy may be justified in these cases. Poor responders have a higher recurrence risk and their approach should be individualized.

Bone mineral: A trojan horse for bone cancers. Efficient mitochondria targeted delivery and tumor eradication with nano hydroxyapatite containing doxorubicin.

Efficient systemic pharmacological treatment of solid tumors is hampered by inadequate tumor concentration of cytostatics necessitating development of smart local drug delivery systems. To overcome this, we demonstrate that doxorubicin (DOX), a cornerstone drug used for osteosarcoma treatment, shows reversible accretion to hydroxyapatite (HA) of both nano (nHA) and micro (mHA) size. nHA particles functionalized with DOX get engulfed in the lysosome of osteosarcoma cells where the acidic microenvironment causes a disruption of the binding between DOX and HA. The released DOX then accumulates in the mitochondria causing cell starvation, reduced migration and apoptosis. The HA+DOX delivery system was also tested in-vivo on osteosarcoma bearing mice. Locally delivered DOX via the HA particles had a stronger tumor eradication effect compared to the controls as seen by PET-CT and immunohistochemical staining of proliferation and apoptosis markers. These results indicate that in addition to systemic chemotherapy, an adjuvant nHA could be used as a carrier for intracellular delivery of DOX for prevention of tumor recurrence after surgical resection in an osteosarcoma. Furthermore, we demonstrate that nHA particles are pivotal in this approach but a combination of nHA with mHA could increase the safety associated with particulate nanomaterials while maintaining similar therapeutic potential.

Late Local Recurrence and Metastasis in Soft Tissue Sarcoma of the Extremities and Trunk Wall: Better Outcome After Treatment of Late Events Compared with Early.

BACKGROUND: Approximately 80% of soft tissue sarcoma (STS) recurrences, local and metastatic disease, are diagnosed within the first 3 years after primary diagnosis and treatment. Recurrences, however, can present after a longer period of remission. Our goal was to identify factors that may predict the risk of late recurrence. METHODS: We identified 677 patients with STS of the extremities and trunk wall from a population-based sarcoma register. Of these, 377 patients were alive and event-free at 3 years and were included for analysis of possible risk factors for late recurrence. RESULTS: Fifty-five of 377 (15%) patients developed late recurrence: 23 local recurrence, 21 metastasis, and 11 both manifestations. With R0 wide surgical margin as reference, R0 marginal (hazard ratio [HR] 2.6; p = 0.02) and R1 (HR 5.0; p = 0.005) margins were risk factors for late local recurrence. Malignancy grade (HR 8.3; p = 0.04) and R0 marginal surgical margin (HR 2.3; p = 0.04) were risk factors for late metastasis. We could not find a statistically significant correlation of late recurrence with many of the generally known risk factors for local recurrence and metastasis in STS. Outcome after treatment of late recurrences was better compared with outcome after treatment of early events. CONCLUSIONS: Late recurrences, albeit relatively rare, do occur. Outcome after treatment was good compared with outcome after early events. Long surveillance of all patients with high-grade STS, especially if R0 wide surgical margin is not achieved in the primary treatment, appear to be well justified.

Loss of NF2 defines a genetic subgroup of non-FOS-rearranged osteoblastoma.

Osteoblastoma is a locally aggressive tumour of bone. Until recently, its underlying genetic features were largely unknown. During the past two years, reports have demonstrated that acquired structural variations affect the transcription factor FOS in a high proportion of cases. These rearrangements modify the terminal exon of the gene and are believed to stabilise both the FOS transcript and the encoded protein, resulting in high expression levels. Here, we applied in-depth genetic analyses to a series of 29 osteoblastomas, including five classified as epithelioid osteoblastoma. We found recurrent homozygous deletions of the NF2 gene in three of the five epithelioid cases and in one conventional osteoblastoma. These events were mutually exclusive from FOS mutations. Structural variations were determined by deep whole genome sequencing and the number of FOS-rearranged cases was less than previously reported (10/23, 43%). One conventional osteoblastoma displayed a novel mechanism of FOS upregulation; bringing the entire FOS gene under the control of the WNT5A enhancer that is itself activated by FOS. Taken together, we show that NF2 loss characterises a subgroup of osteoblastomas, distinct from FOS-rearranged cases. Both NF2 and FOS are involved in regulating bone homeostasis, thereby providing a mechanistic link to the excessive bone growth of osteoblastoma.

High Recurrence Rate of Myxofibrosarcoma: The Effect of Radiotherapy Is Not Clear.

BACKGROUND: Myxofibrosarcoma (MFS) is one of the more common types of soft-tissue sarcoma (STS) in patients over 60 years of age. Local recurrence (LR) rates have been reported to be higher compared to other STS types. PATIENTS AND METHODS: Using a population-based series from the southern Sweden health care region, 56 consecutive patients with MFS and localized disease at diagnosis were analyzed with respect to LR and distant metastases after surgery ± adjuvant treatment. RESULTS: The overall local recurrence (n = 15) and metastasis (n = 13) rates were 27% and 21%, respectively; 6 patients had both. Surgical margin was the only statistically significant prognostic factor for LR. Patients operated with a marginal margin had an HR of 4.5 (CI 1.3-15.1, p=0.02) and those operated with an intralesional margin 9.4 (CI 2.0-43.5, p=0.004) compared to those operated with a wide surgical margin. There was no difference in the LR rate depending on radiotherapy or not, although the latter group had smaller and more superficial tumors. 23 patients received radiotherapy, 9 of whom developed LR, all within the irradiated field. A tumor size >5 cm and intralesional surgical margin were shown to be risk factors for distant metastases. CONCLUSIONS: The rate of LR for patients with myxofibrosarcoma was high. The impact of RT on local tumor control was unclear. The surgical margin was important for both local and distant tumor control. Large tumor size was a risk factor for distant metastasis.

Soft-tissue sarcoma in adolescents and young adults compared with older adults: A report among 5000 patients from the Scandinavian Sarcoma Group Central Register.

BACKGROUND: In recent years, there has been growing awareness of the distinct characteristics of adolescents and young adults (AYA) diagnosed with cancer. Soft-tissue sarcoma (STS) accounts for approximately 1% of all cancers diagnosed in adults and 8% of cancers diagnosed in AYA. To the best of our knowledge, only a few sarcoma registers include data regarding histological subtype, age at diagnosis, and detailed clinical information. Therefore, little is known regarding clinical presentation and outcomes in AYA diagnosed with STS. METHODS: Using the Scandinavian Sarcoma Group Central Register, data were obtained regarding 4977 patients who were diagnosed with STS for the period between 1986 and 2011. AYA (those aged 18-39 years) were compared with older adults (OA; those aged 40-80 years) with respect to clinical presentation, treatment, and outcome. RESULTS: There were 868 AYA and 4109 OA. Overall and by STS subtype, there were significant differences noted between AYA and OA with regard to presentation, treatment, and survival. The distribution of STS subtypes was different between OA and AYA (eg, OA were more likely to be diagnosed with malignant fibrous histiocytoma compared with AYA [34% vs 16%; P < .001]). OA also were more likely to have tumors measuring ≥5 cm (68% vs 56%; P < .001) and a higher malignancy grade (75% vs 67%; P < .001). In the majority of STS subtypes AYA had significantly better overall survival and less disease recurrence compared with OA, but this finding was not true for those with malignant peripheral nerve sheath tumors. CONCLUSIONS: There are several differences between AYA and OA with STS with regard to presentation, treatment, and survival, and such differences must be taken into consideration when designing clinical trials. Additional work also is needed to characterize the potential biological mechanisms underlying these differences.

[Respiratory failure and neurological impairment in a child with Duchenne muscular dystrophy following minor trauma]. / Ökad risk för fettembolisyndrom vid Duchennes muskeldystrofi.

Fat Embolism Syndrome (FES) is a rare and often lethal condition, associated with trauma or surgery. It is more serious than a typical fat embolism seen after a fracture in a long bone. FES is a triad of symtoms, including respiratory failure, abnormal neurology and petechial bleeding. FES is a diagnosis of exclusion. The incidence of FES is higher among adults compared to children. One possible explanation for this is the greater proportion of fat in the adult bone marrow. Children with Duchennes muscular dystrophy have a significantly increased risk of FES compared to both other children and adults. There is no specific treatment. Treatment is supportive until the respiratory and cardiovasculatory symtoms pass.

Ewing sarcoma of the mobile spine; predictive factors for survival, neurological function and local control. A Scandinavian sarcoma group study with a mean follow-up of 12 years.

Object: Many patients with Ewing sarcoma (ES) of the mobile spine present with neurologic symptoms leading to emergency decompressive surgery. Only rarely is optimal treatment involving neo-adjuvant chemotherapy followed by en bloc excision possible. The purpose of this study was to study treatment, neurologic and oncologic outcome in patients with ES of the mobile spine. Methods: Twenty-four patients diagnosed between 1986 and 2012 were identified through the Scandinavian Sarcoma Group registry. Charts were reviewed in order to assess details in patient characteristics, neurologic status, treatment and outcome. Prognostic factors were analyzed with respect to local control, disease-free survival and overall survival. Results: Neurologic symptoms were frequently observed at presentation, being present in 19/23 patients with documented neurologic status. Most (13/19) patients had a complete neurologic recovery regardless of whether or not emergency decompressive surgery was performed. The majority (18/24) of patients were treated with definitive radiotherapy. However, only 9/17 received the recommended dose of  ≥  50.4 Gy. The disease-free and overall survival rates were 48% and 57% at 5 and 10 years, respectively. The local recurrence rates were 19% and 27% at 5 and 10 years, respectively. Only year of diagnosis, categorized into periods with significant changes in chemotherapy protocols, was a significant factor for local recurrence, but there was a trend (p = 0.06) for an increased risk of a local recurrence if emergency decompressive surgery was performed. Conclusion: Patients with ES of the mobile have a relatively favorable prognosis. Nonetheless, local recurrence rate is high for this group of patients for which local treatment mainly relies on definitive radiotherapy. Emergency decompressive surgery may increase the risk for local recurrence.

The Scandinavian Sarcoma Group Central Register: 6,000 patients after 25 years of monitoring of referral and treatment of extremity and trunk wall soft-tissue sarcoma.

Purpose - We wanted to examine the potential of the Scandinavian Sarcoma Group (SSG) Central Register, and evaluate referral and treatment practice for soft-tissue sarcomas in the extremities and trunk wall (STS) in the Nordic countries. Background - Based on incidence rates from the literature, 8,150 (7,000-9,300) cases of STS of the extremity and trunk wall should have been diagnosed in Norway, Finland, Iceland, and Sweden from 1987 through 2011. The SSG Register has 6,027 cases registered from this period, with 5,837 having complete registration of key variables. 10 centers have been reporting to the Register. The 5 centers that consistently report treat approximately 90% of the cases in their respective regions. The remaining centers have reported all the patients who were treated during certain time periods, but not for the entire 25-year period. Results - 59% of patients were referred to a sarcoma center untouched, i.e. before any attempt at open biopsy. There was an improvement from 52% during the first 5 years to 70% during the last 5 years. 50% had wide or better margins at surgery. Wide margins are now achieved less often than 20 years ago, in parallel with an increase in the use of radiotherapy. For the centers that consistently report, 97% of surviving patients are followed for more than 4 years. Metastasis-free survival (MFS) increased from 67% to 73% during the 25-year period. Interpretation - The Register is considered to be representative of extremity and trunk wall sarcoma disease in the population of Scandinavia, treated at the reporting centers. There were no clinically significant differences in treatment results at these centers.

Referral patterns, treatment and outcome of high-grade malignant bone sarcoma in Scandinavia--SSG Central Register 25 years' experience.

AIMS: The objectives of this study were to present changes in referral patterns, treatment and survival in patients with high-grade malignant bone sarcoma in Sweden and Norway based on data in the Scandinavian Sarcoma Group (SSG) Central Register. METHOD: Data on 1,437 patients with diagnosis 1986-2010 was analyzed. RESULTS: Osteosarcoma was the most frequentl diagnosis (45%), followed by Ewing sarcoma (21%) and chondrosarcoma (17%). Thirty-one percent of Swedish and 41% of Norwegian patients had tumors in the axial skeleton. Eighty-six percent of extremity tumors and 66% of axial tumors were referred to a sarcoma center prior to unplanned surgery or biopsy. During the past decade, limb salvage surgery has risen from under 50% to over 80%. Five-year overall survival in non-metastatic osteosarcoma was 70% for extremity tumors, and 35% for axial tumors. No improvement in osteosarcoma survival was observed during the last decade. Five-year survival in Ewing sarcoma improved from 50% to 69%. CONCLUSION: Referral patterns in bone sarcomas have improved. However, greater efforts should be dedicated to improving referral of patients with possible tumors in the axial skeleton to multidisciplinary teams (MDTs). Overall survival of patients with high-grade malignant bone sarcomas in Sweden and Norway is in line with other reports.

Prognostic factors and follow-up strategy for superficial soft-tissue sarcomas: Analysis of 622 surgically treated patients from the scandinavian sarcoma group register.

BACKGROUND AND OBJECTIVES: Our study aimed to describe the clinical outcome of patients with superficial soft-tissue sarcomas (SSTS), define prognostic factors and provide evidence for a rational surveillance scheme. METHODS: Data for 622 consecutive, surgically treated SSTS patients were retrieved from the Scandinavian Sarcoma Group Register. We assessed the rates of local recurrence (LR) and metastasis (M), as well as overall survival (OS), local recurrence free-survival (LRFS) and metastasis-free survival (MFS) of the cohort. RESULTS: The incidence of LR and M was 9% and 12%, respectively. OS at 5 years was 79%, LRFS was 74% and MFS 76%. Factors that affected OS, LRFS, and MFS were tumor size and patient age. Additionally, tumor grade was an independent prognostic factor for LRFS. The majority of LR and M events were observed the first 2 years of follow-up. Clear surgical margins were correlated to lower risk for LR. Selected patients benefited from adjuvant radiotherapy. CONCLUSIONS: SSTS have a favourable prognosis, which is mainly determined by tumour-associated factors. Adequate surgical margins are important for local control, whereas radiotherapy has a secondary role. The data support current surveillance schemes, with a closer follow-up the first 2 years after surgery.

Small soft tissue sarcomas do metastasize: identification of high-risk tumors.

BACKGROUND: Small (≤ 5 cm) soft tissue sarcomas (STS) of the extremities and the trunk wall generally have a favorable prognosis. However, 1 of 10 patients do develop metastases, and we therefore aimed to determine predictors of metastasis in a population-based cohort of patients with small STSs. PATIENTS AND METHODS: In the southern Sweden health care region, 848 adult patients with STS of the extremities or the trunk wall were diagnosed between 1986 and 2010. Of these, 243 STS (29 %) were ≤5 cm. Prognostic evaluation was performed in 229 patients with localized disease at diagnosis, 181 of whom had histologic high-grade tumors. RESULTS: None of the 48 patients with low-grade tumors developed metastases, whereas 24 of 181 patients with high-grade tumors (13 %) tumors did. Presence of either tumor necrosis or vascular invasion predicted development of metastases with a hazard ratio of 2.9 (95 % CI, 1.0-7.9), and tumors with both factors had a hazard ratio of 12 (95 % CI, 4.1-37) for metastasis (adjusted for size). CONCLUSIONS: Our population-based series of STSs ≤5 cm demonstrate an overall good prognosis with metastases developing in 13 % of the patients with high-grade tumors. Tumor necrosis and vascular invasion were the major predictors of metastatic disease in this subset. Tumors with both these risk factors metastasized in 8 of 18 patients, which corresponds to a 12-fold increased risk of metastasis. These findings suggest that although small STS generally are linked to a good prognosis, necrosis and vascular invasion are features indicating biologically aggressive tumors for which treatment and surveillance should equal that for larger tumors.

[Most musculoskeletal soft tissue tumors are benign]. / Fetthaltiga mjukdelstumörer i rörelseapparaten ofta godartade.

Most musculoskeletal soft tissue tumors are benign, lipoma being the most common. Malignant soft tissue tumors may be difficult to clinically distinguish from benign. Scandinavian recommendations are that all lesions suspicious for sarcoma be referred to a sarcoma center. This has led to improved tumor control and less post-operative functional deficits. Magnetic resonance imaging (MRI) can reliably diagnose lipomas, and further work-up is not necessary. Lipomas can be treated at the local hospital. All deep seated musculoskeletal tumors (under the muscle fascia) not unequivocally lipomas should be referred to a sarcoma center. All superficial (subcutaneous) musculoskeletal tumors larger than 5 cm and not unequivocally lipomas should be referred to a sarcoma center.

Radiation-associated angiosarcoma after breast cancer: high recurrence rate and poor survival despite surgical treatment with R0 resection.

BACKGROUND: Secondary angiosarcoma of the breast is a rare but severe long-term complication of breast cancer treated with breast-conserving surgery and radiotherapy. We characterized a population-based cohort of patients with secondary angiosarcomas from two tertiary hospitals to investigate this complication with respect to surgical treatment and outcome. METHODS: We identified 35 patients with a history of radiation for breast cancer that developed angiosarcoma in the irradiated field from 1990 to 2009. Of these, 31 underwent surgery and were included for analysis. RESULTS: Angiosarcoma developed after median 7 years (range 3-25 years). R0 resection was obtained in 23 of 31 patients after primary treatment. Local recurrence developed in 19 patients after median 6 months (range 1-89 months). Regional and distant metastases occurred in 13 patients after median 17 months (range 2-50 months); nine which also had local recurrence. Patients whose local recurrence could be operated on had a better survival after treatment than those who were not considered for surgical treatment, median 34 months (range 6-84 months) compared with 6 months (range 5-24 months). The median disease-free survival and disease-specific survival was 16 and 37 months, respectively. CONCLUSIONS: Despite R0 resection, two-thirds of the patients developed a local recurrence. Survival among those with local recurrence was better if the patient could be treated with surgery. Overall, the prognosis was dismal and median DSS was just over 3 years.

Delays in the management of retroperitoneal sarcomas.

Retroperitoneal sarcomas are rare and treatment should optimally be centralized. Despite successful centralization with 90% of the patients referred prior to surgery, delays occur, which led us to assess lead times in a population-based series. Method. Patients diagnosed with retroperitoneal sarcoma in the southern Sweden health care region 2003-2009 were eligible for the study. Data on referrals and diagnostic investigations were collected from clinical files from primary health care, local hospitals, and from the sarcoma centre. Lead times were divided into patient delays and health care delays caused by primary health care, local hospitals, or procedures at the sarcoma centre. Results. Complete data were available from 33 patients and demonstrated a median patient delay of 23 days (0-17 months) and median health care delay of 94 days (1-40 months) with delays of median 15 days at the general practitioner, 36 days at local hospitals, and 55 days at the sarcoma centre. Conclusion. Centralization per se is not sufficient for optimized and efficient management. Our findings suggest that delays can be minimized by direct referral of patients from primary health care to sarcoma centers and indicate that development of coordinated diagnostic packages could shorten delays at the sarcoma centre.

Changing clinical presentation of angiosarcomas after breast cancer: from late tumors in edematous arms to earlier tumors on the thoracic wall.

Angiosarcoma is a rare complication of breast cancer treatment. In order to define predictors, clinical presentation, and outcome, we characterized a population-based 50-year cohort of angiosarcomas after breast cancer. Clinical data were collected from all females with previous breast cancer who developed angiosarcomas/lymphangiosarcomas on the thoracic wall/upper extremity between 1958 and 2008 in the Southern Swedish health care region. In total, 31 angiosarcomas developed at a median age of 71 years. The patients formed two distinct groups; 14 females treated for breast cancer with radical mastectomy and radiotherapy 1949-1988 developed angiosarcomas in edematous arms (Stewart-Treves syndrome) after median 11 years, and 17 females treated by segmental resection, anti-hormonal treatment and radiotherapy 1980-2005 developed angiosarcomas in the irradiated field on the thoracic wall after median 7.3 years. The clinical presentations were heterogeneous and included hematoma-like lesions, multiple bluish-reddish nodules, and asymptomatic lumps. The overall 5-year survival was 16%. In this population-based cohort, the early angiosarcomas developed in edematous arms after radical mastectomies, whereas more recent cases occurred after a shorter time period in the irradiated fields following breast conserving surgery. We conclude that the clinical presentation of angiosarcomas has changed, parallel with altered treatment principles for breast cancer.