Treatment at relapse for synovial sarcoma of children and adolescents: A multi-institutional European retrospective analysis.

PURPOSE: Though the prognosis for pediatric patients with localised synovial sarcoma (SS) is generally good, the chances of being cured after relapse are limited. This study describes a retrospective multi-institutional series of relapsing SS patients treated at six selected European referral centers for pediatric sarcoma. PATIENTS AND METHODS: The study included 41 patients <21 years with relapsing SS, treated between 2002 and 2022. The analysis included patient's characteristics at first diagnosis, first-line treatments, clinical findings at relapse, and second-line treatment modalities. RESULTS: The first relapse occurred within 3-132 months (median 18 months) after first diagnosis and was local in 34%, metastatic in 54%, and both in 12%. Treatment at first relapse included surgery in 56% of cases, radiotherapy in 34%, and systemic therapy in 88%. In all, 36 patients received second-line medical treatment, that was chemotherapy in 32 cases (with 10 different regimens) and targeted therapy in four. No patient was included in an early-phase clinical trial as second-line therapy-line therapy. Overall response rate was 42%. Median event-free survival (EFS) was 12 months, postrelapse 5-year EFS was 15.8%. Median overall survival (OS) was 30 months, postrelapse 5-year OS was 22.2%. At the Cox's multivariable regression analysis, OS was significantly associated with time and type of relapse. CONCLUSION: Pediatric patients with relapsed SS have a poor prognosis and generally receive an individualized approach, due to the lack of a uniform standardized approach. New comprehensive strategies are needed to improve the knowledge on the biologic landscape of SS and develop tailored prospective clinical trials.

Primary Pleuropulmonary Synovial Sarcoma: Report of Two Cases and a Comprehensive Review of the Literature.

Primary sarcomas of the lung represent less than 0.5% of all primary lung tumors and comprise a heterogeneous group of malignancies including synovial sarcoma (SS). Primary pleuropulmonary SS has non-specific presentations, such as chest pain, shortness of breath and cough, and its associated imaging features resemble those of other intrathoracic malignancies. The diagnosis of these tumors needs to be confirmed by cytogenetic and molecular studies. Here, we describe two rare cases of primary pleuropulmonary SS who were admitted to our hospital. We also provide a concise review of clinical, radiological, and histopathological characteristics of pleuropulmonary SS after exploring 168 studies (415 corresponding patients) that were identified through a literature search.

Synovial Sarcoma in Children, Adolescents, and Young Adults: A Report From the Children's Oncology Group ARST0332 Study.

PURPOSE: Synovial sarcoma (SS) is the second most common malignant soft tissue tumor in children. ARST0332 evaluated a risk-based treatment strategy for young patients with soft tissue sarcoma designed to limit therapy for low-risk (LR) disease and to test neoadjuvant chemoradiotherapy for unresected higher-risk disease. METHODS: Newly diagnosed patients with SS age < 30 years were assigned to four treatment arms based on disease features: A (surgery only), B (55.8 Gy radiotherapy [RT]), C (ifosfamide and doxorubicin [ID] chemotherapy plus 55.8 Gy RT), and D (neoadjuvant ID and 45 Gy RT, then surgery and RT boost based on margins followed by adjuvant ID). Patients treated in Arms A and B were considered LR, arms C and D without metastases as intermediate-risk (IR), and those with metastases as high-risk (HR). RESULTS: Of the 146 patients with SS enrolled, 138 were eligible and evaluable: LR (46), IR (71), and HR (21). Tumors were 80% extremity, 70% > 5 cm, 70% high-grade, 62% invasive, 95% deep, and 15% metastatic. Treatment was on arm A (29.7%), B (3.6%), C (16.7%), and D (50%). There were no toxic deaths and four unexpected grade 4 adverse events. By risk group, at a median follow-up of 6.8 years, estimated 5-year event-free survival was LR 82%, IR 70%, and HR 8%, and overall survival was LR 98%, IR 89%, and HR 13%. After accounting for the features that defined risk category, none of the other patient or disease characteristics (age, sex, tumor site, tumor invasiveness, and depth) improved the risk stratification model. CONCLUSION: The risk-based treatment strategy used in ARST0332 produced favorable outcomes in patients with nonmetastatic SS relative to historical controls despite using RT less frequently and at lower doses. The outcome for metastatic SS remains unsatisfactory and new therapies are urgently needed.

Synovial Sarcoma of the Hand and Foot: An Institutional Review.

OBJECTIVES: Synovial sarcomas (SS) arising in distal extremities are rare and have been studied using mostly case reports and small series. We aimed to evaluate clinical presentation and survival outcomes for patients with hand or foot SS. MATERIALS AND METHODS: We conducted a retrospective review of 84 patients diagnosed with primary hand (n=20) and foot (n=64) SS between 1979 and 2019. Progression-free survival (PFS), overall survival (OS), local recurrence-free survival and metastasis-free survival were estimated using the Kaplan-Meier method and log-rank test. Cox-proportional hazards regression was used to estimate the hazard ratios. RESULTS: Of 84 patients, 63 (75%) presented with localized disease with 36 years median age at diagnosis (range: 4 to 76) and 21 (25%) with metastasis with 30 years median age at diagnosis (range: 15 to 64). Among patients presenting with localized disease, (1) 5 years-PFS, OS, local recurrence-free survival, and metastasis-free survival rates were 82%, 88%, 100%, and 86%, respectively. (2) Tumor size <3.0 cm corresponded to 95% 5 years-PFS (vs. 84% for 3.0 to 4.9 cm, 53% for ≥5.0 cm; P=0.007) and 100% 5 years-OS (vs. 77% for ≥3.0 cm; P=0.04). (3) Patients with ≥5.0 cm (vs. <3.0 cm) tumor size had 7.99 (95% confidence interval: 1.68, 37.91) times higher hazard of progression. Remarkably, patients presenting with metastasis had 50% 5 years-OS rate. Also, younger age (15 to 39 vs. 40 y and above) predicted better OS among patients presenting with localized disease (P=0.04) and with metastasis (P=0.03). CONCLUSIONS: Survival outcomes are favorable for younger patients with <3.0 cm hand or foot SS. Local control is excellent, but we observed larger tumor size to be associated with poorer outcomes. Therefore, we recommend consideration of systemic therapy for patients with ≥3.0 cm hand or foot SS.

Is perioperative chemotherapy recommended in childhood and adolescent patients with synovial sarcoma? A systematic review.

OBJECTIVE: Synovial sarcoma is the most common soft tissue sarcomas among childhood and adolescents, accounting for 8-10% of all soft tissue sarcoma. Synovial sarcoma is considered a relatively chemosensitive tumor compared with other soft tissue sarcomas. However, the role of perioperative chemotherapy in synovial sarcoma remains controversial. The purpose of this systematic review is to evaluate the role of perioperative chemotherapy in childhood and adolescent patients with synovial sarcoma. METHODS: We evaluated studies published between 1 January 1990 and 31 December 2017. The following databases were searched: MEDLINE, Cochrane database (via PubMed) and Ichushi (in Japanese). RESULTS: The search yielded 216 articles in English and Japanese. After the initial screening, based on the title and abstract, 160 articles were excluded. As a second screening, we then assessed the full text of the remaining 56 articles for eligibility. Finally, 10 articles were included in the systematic review. Surgical resection with R0 margin alone was recommended because of the excellent results of two prospective studies. Meta-analysis was performed using data from two retrospective studies of 261 patients. Perioperative chemotherapy did not have a significant effect on survival and event-free survival. CONCLUSIONS: We weakly do not recommend perioperative chemotherapy in patients with non-metastatic synovial sarcoma ≤ 5 cm when R0 resection is acquired. There was no consensus concerning the role of perioperative chemotherapy in patients with synovial sarcoma > 5 cm or those with ≤5 cm who undergo R1 or R2 resection.

Laryngeal Synovial Sarcoma: A Systematic Review of the Last 40 Years of Reported Cases.

Primary laryngeal synovial sarcoma is an extremely rare tumor predominantly affecting young adults. There are currently no well-defined guidelines to direct investigation and management, and treatment is largely based on what is known for synovial sarcoma of the upper and lower limbs. This PROSPERO-registered study aims to review the diagnostic methods, treatment regimens, and survival outcomes for patients with synovial sarcoma of the larynx. A systematic search of databases Medline, Embase, SCOPUS, and Web of Science was undertaken in December 2017. The literature search identified 1031 potentially relevant studies, and after the deletion of duplicates and excluded papers, 98 full-text articles were screened. A total of 39 cases were reviewed from 32 studies in the data extraction. The average age at the time of laryngeal synovial sarcoma diagnosis was 32 years (range, 11-79 years). In all cases (n = 39), patients underwent wide surgical excision, with 20 patients requiring a partial or total laryngectomy. A total of 18 patients received adjuvant and 3 received neoadjuvant radiotherapy. Chemotherapy was used in 10 cases, with ifosfamide the most frequently used agent. There was considerable variability in the order and combinations of the abovementioned treatments. No clinicopathologic factors or treatment regimens were associated with improved overall survival or lower rate of recurrence. There is a paucity of literature and heterogeneity in clinical approaches to this highly aggressive sarcoma. Reporting of cases must be standardized and formal guidelines must be established to guide clinical management.

Evaluation of conditional treatment effects of adjuvant treatments on patients with synovial sarcoma using Bayesian subgroup analysis.

BACKGROUND: The impact of adjuvant chemotherapy or radiation therapy on the survival of patients with synovial sarcoma (SS), which is a rare soft-tissue sarcoma, remains controversial. Bayesian statistical approaches and propensity score matching can be employed to infer treatment effects using observational data. Thus, this study aimed to identify the individual treatment effects of adjuvant therapies on the overall survival of SS patients and recognize subgroups of patients who can benefit from specific treatments using Bayesian subgroup analyses. METHODS: We analyzed data from patients with SS obtained from the surveillance, epidemiology, and end results (SEER) public database. These data were collected between 1984 and 2014. The treatment effects of chemotherapy and radiation therapy on overall survival were evaluated using propensity score matching. Subgroups that could benefit from radiation therapy or chemotherapy were identified using Bayesian subgroup analyses. RESULTS: Based on a stratified Kaplan-Meier curve, chemotherapy exhibited a positive average causal effect on survival in patients with SS, whereas radiation therapy did not. The optimal subgroup for chemotherapy includes the following covariates: older than 20 years, male, large tumor (longest diameter > 5 cm), advanced stage (SEER 3), extremity location, and spindle cell type. The optimal subgroup for radiation therapy includes the following covariates: older than 20 years, male, large tumor (longest diameter > 5 cm), early stage (SEER 1), extremity location, and biphasic type. CONCLUSION: In this study, we identified high-risk patients whose variables include age (age > 20 years), gender, tumor size, tumor location, and poor prognosis without adjuvant treatment. Radiation therapy should be considered in the early stages for high-risk patients with biphasic types. Conversely, chemotherapy should be considered for late-stage high-risk SS patients with spindle cell types.

Treatment and outcomes for synovial sarcoma patients in Western Australia: the role of neoadjuvant chemoradiotherapy.

BACKGROUND: This is a retrospective review of synovial sarcoma (SS) patients treated over the last 12 years in Western Australia (WA). SS is both chemo and radiotherapy sensitive. Results of trials in adjuvant chemotherapy are conflicting and there is limited support for neoadjuvant chemotherapy. The use of combined chemoradiotherapy is based on institutional preferences. AIM: We reviewed the outcomes for SS patients treated in WA over a 12 year period focusing on patients who received neoadjuvant chemoradiotherapy (NACRT). METHODS: Patient details including demographics, histopathology, treatment details, were obtained from the WA sarcoma database (2006-2018). Progression free survival (PFS) and overall survival (OS) were derived for whole cohort. RESULTS: Twenty seven patients were identified with SS with equal gender incidence. Median age of the cohort was 36 (14-76) years. The most common primary site of disease was extremity (81.5%). 22/27 patients presented with only localized disease and 59.2% of these received neo-adjuvant treatment. Of those who received neoadjuvant treatment, 56.2% had NACRT, while 25.0% and 18.7% of patients had chemotherapy and radiotherapy respectively. Mesna, doxorubicin, ifosfamide, dacarbazine (MAID) was the most commonly used chemotherapy regimen as neoadjuvant or adjuvant treatment while ifosfamide (93.7%) was the most commonly used chemotherapy drug in any setting. There was no reported case of disease progression in group of patients who received NACRT apart from one patient who had oligometastatic disease at diagnosis. Median OS of the whole cohort was 38 months while median PFS was 24 months. Bone marrow toxicity was the most commonly reported high grade toxicity in NACRT group (55.5%) but there were no treatment related deaths. CONCLUSION: NACRT is not widely adopted and treatment is based on institutional preferences, however our data shows that NACRT is a feasible therapy option. NACRT should be evaluated prospectively in a randomized trial.

Systematic literature review of clinical outcomes in adults with metastatic or advanced synovial sarcoma.

Background: Synovial sarcoma (SS) is a rare, aggressive soft tissue sarcoma with a poor prognosis after metastasis. The objective of this study was to conduct a systematic review of the clinical evidence for therapeutic options for adults with metastatic or advanced SS. Materials & methods: Relevant databases were searched with predefined keywords. Results: Thirty-nine publications reported clinical data for systemic treatment and other interventions. Data on survival outcomes varied but were generally poor (progression-free survival: 1.0-7.7 months; overall survival: 6.7-29.2 months) for adults with metastatic and advanced SS. A high frequency of neutropenia with systemic treatment and low quality of life post-progression were reported. Conclusion: Reported evidence suggests poor outcomes in adults with metastatic and advanced SS and the need for the development of new treatment modalities.

Radiotherapy is Associated With Improved Survival in Patients With Synovial Sarcoma Undergoing Surgery: A National Cancer Database Analysis.

BACKGROUND: Previous studies have demonstrated an association of perioperative radiotherapy (RT) with improved survival in patients with synovial sarcoma (SS) undergoing surgery, but the mechanism for this is unknown. In this study, we sought to further analyze this association using a hospital-based data set where data on chemotherapy administration and surgical margin status are available. METHODS: Using the National Cancer Database, we identified 1216 patients with SS (aged ≥18 y) from 2004-2012 undergoing surgery. Cox proportional hazards analysis was used to study the effect of clinicopathologic variables on overall survival (OS). RESULTS: Mean age at diagnosis was 41.5 y (range 18-90), and 71.3% of tumors were high grade; 22.9% underwent surgery alone, 59.6% received RT with surgery, 44.2% received chemotherapy with surgery, and 26.3% received trimodality therapy. Age, sex, grade, Charlson-Deyo score, and RT (hazard ratio, 0.676; 95% confidence interval, 0.519-0.880; P = 0.004) were associated with improved OS, whereas chemotherapy (hazard ratio, 1.20; 95% confidence interval, 0.899-1.60; P = 0.217) and surgical margin status were not. Trimodality therapy with surgery, RT, and chemotherapy was associated with improved OS when compared with therapy with surgery and chemotherapy alone. CONCLUSIONS: In patients with SS undergoing surgery, we observed a significant improved association of OS with the addition of RT when adjusting for comorbidity score, margin status, and receipt of chemotherapy. These data further support routine implementation of RT in the treatment of patients with SS, including those receiving aggressive multimodality and trimodality care.

Treatment of limb synovial sarcoma with metastasis at presentation.

Limb synovial sarcoma (LSS) patients with metastasis at presentation usually have a very poor prognosis. Little is known about survival prediction and risk factors in these patients owing to the condition's rarity. Thus, this study examined the survival and prognostic variables of metastatic LSS.Clinical data for LSS patients with metastasis at presentation from 1975 to 2016 were obtained from the surveillance, epidemiology, and end results database. The Kaplan-Meier method was used to determine the survival curves. Univariate and multivariate Cox regression analysis were conducted to identify the prognostic predictors.The study enrolled 217 patients. Male predominance was observed in the metastatic LSS group. The median age at diagnosis of this population was 40 years. The subtypes were "not otherwise specified" (49.8%), spindle cell (32.7%), biphasic (17.1%), and epithelioid cell (0.5%). The 3-year overall and cancer-specific survival rates of the entire group were 27.2% and 28.3%, respectively. Tumor size <10 cm, surgery, radiotherapy, and chemotherapy were independent predictors of improved overall and cancer-specific survival in the multivariate analyses.Comprehensive treatment for LSS patients with metastasis at diagnosis is necessary and effective and can prolong survival.

Clinical outcomes of patients with advanced synovial sarcoma or myxoid/round cell liposarcoma treated at major cancer centers in the United States.

BACKGROUND: Outcomes data regarding advanced synovial sarcoma (SS) and myxoid/round cell liposarcoma (MRCL) are limited, consisting primarily of retrospective series and post hoc analyses of clinical trials. METHODS: In this multi-center retrospective study, data were abstracted from the medical records of 350 patients from nine sarcoma centers throughout the United States and combined into a registry. Patients with advanced/unresectable or metastatic SS (n = 249) or MRCL (n = 101) who received first-line systemic anticancer therapy and had records of tumor imaging were included. Overall survival (OS), time to next treatment, time to distant metastasis, and progression-free survival (PFS) were evaluated using the Kaplan-Meier method and Cox regression. RESULTS: At start of first-line systemic anticancer therapy, 92.4% of patients with SS and 91.1% of patients with MRCL had metastatic lesions. However, 74.7% of patients with SS and 72.3% of patients with MRCL had ≥2 lines of systemic therapy. Median OS and median PFS from first-line therapy for SS was 24.7 months (95% CI, 20.9-29.4) and 7.5 months, respectively (95% CI, 6.4-8.4). Median OS and median PFS from start of first-line therapy for MRCL was 29.9 months (95% CI, 27-44.6) and 8.9 months (95% CI 4.5-12.0). CONCLUSIONS: To the best of our knowledge, this is the largest retrospective study of patients with SS and MRCL. It provides an analysis of real-world clinical outcomes among patients treated at major sarcoma cancer centers and could inform treatment decisions and design of clinical trials. In general, the survival outcomes for this selected population appear more favorable than in published literature.

Underlying Ossification Phenotype in a Murine Model of Metastatic Synovial Sarcoma.

Synovial sarcoma, an uncommon cancer, typically affects young adults. Survival rates range from 36% to 76%, decreasing significantly when metastases are present. Synovial sarcomas form in soft tissues, often near bones, with about 10% demonstrating ossification in the tumor. The literature is inconclusive on whether the presence of ossification portends a worse prognosis. To this end, we analyzed our genetic mouse models of synovial sarcoma to determine the extent of ossification in the tumors and its relationship with morbidity. We noted higher ossification within our metastatic mouse model of synovial sarcoma. Not only did we observe ossification within the tumors at a frequency of 7%, but an even higher frequency, 72%, of bone reactivity was detected by radiography. An enrichment of bone development genes was associated with primary tumors, even in the absence of an ossification phenotype. In spite of the ossification being intricately linked with the metastatic model, the presence of ossification was not associated with a faster or worse morbidity in the mice. Our conclusion is that both metastasis and ossification are dependent on time, but that they are independent of one another.

The Role of Neoadjuvant Chemotherapy in Resectable Primary Synovial Sarcoma.

BACKGROUND: The role of neoadjuvant chemotherapy for localized synovial sarcoma is still controversial. This study aimed to explore the influence of neoadjuvant chemotherapy combined with surgery in localized synovial sarcoma through analysis of our hospital's patient records. PATIENTS AND METHODS: A total of 122 patients diagnosed with synovial sarcoma were enrolled in this study from January 1980 to December 2016 at the Cancer Institute Hospital of The Japanese Foundation for Cancer Research. The impact of neoadjuvant chemotherapy on overall survival was assessed to show how clinicopathological factors (e.g. age, tumor size, treatment, dose intensity, pathological pattern and histological grading) influenced patient prognosis. RESULTS: Among 106 patients, 76 (71.7%) received neoadjuvant chemotherapy and 30 (28.3%) did not. The median follow-up was 39.2 (range=12-286) months. The 5-year and 10-year overall survival rates were 65.4% and 58.4% respectively. The tumor size and histological grade influenced the patient's overall survival (p<0.05). Among the patients with grade 2 tumor, tumor size did not influence prognosis. Neoadjuvant chemotherapy improved the overall survival of patients who had grade 3 tumors. CONCLUSION: Treatment with neoadjuvant chemotherapy proved beneficial for high-risk patients with grade 3 synovial sarcoma but was not effective for those with low-risk and grade 2 tumor. Tumor size and histological grade were important factors in patient prognosis but had no connection with pathological patterns.

Single-Institution Experience of Synovial Sarcoma.

OBJECTIVES: The purpose of this study was to investigate the patient population and outcomes of synovial sarcoma at a single institution. METHODS: A retrospective review of the medical records of 28 patients with synovial sarcoma diagnosed from 1992 to 2017 was performed. Demographics, staging, disease location, treatment, and response to treatment were reviewed. RESULTS: Individuals with larger tumors at the time of presentation had an increased risk of death. An additional factor associated with poor prognosis in synovial sarcoma was increasing patient age. The patient population had a higher rate of nonextremity disease and lower overall survival when compared with national averages. CONCLUSIONS: Nonextremity disease and large size of tumor at presentation may have contributed to the disparity in institutional outcomes from the national averages. The advanced presentation of synovial sarcoma remains a significant challenge in improving patient survival.

Prognostic relevance of SMC family gene expression in human sarcoma.

OBJECTIVE: To explore the prognostic value of the expression of genes encoding structural maintenance of chromosomes (SMCs) in human sarcoma. RESULTS: We found that the levels of SMC1A, SMC2, SMC3, SMC4, SMC5 and SMC6 mRNA were all higher in most tumors compared to normal tissues, and especially in sarcoma. According to the Cancer Cell Line Encyclopedia (CCLE), SMC1A, SMC2, SMC3, SMC4, SMC5 and SMC6 are also highly expressed in sarcoma cell lines. Results of Gene Expression Profiling Interactive Analysis (GEPIA) indicated that high expression of SMC1A was significantly related to poor overall survival (OS) (p<0.05) and disease-free survival (DFS) in sarcoma (p<0.05). Additionally, strong expression of SMC2 was significantly related to poor OS in sarcoma (p<0.05). In contrast, SMC3, SMC4, SMC5, and SMC6 expression had no significant impact on OS or DFS in sarcoma. CONCLUSIONS: Expression of SMC family members is significantly different in sarcoma relative to normal tissues, and SMC1A and SMC2 may be useful as prognostic biomarkers. METHODS: We performed a detailed comparison of cancer and normal tissues regarding the expression levels of mRNA for SMC family members in various cancers including sarcoma through ONCOMINE and GEPIA (Gene Expression Profile Interactive Analysis) databases.

Pericardial Synovial Sarcoma: Case Report, Literature Review and Pooled Analysis.

BACKGROUND: Pericardial synovial sarcomas (PSS) are very rare tumors, with dismal prognosis and limited data. We describe the clinical features and identify prognostic factors of primary PSS. CASE REPORT: We describe the case of a 56-year-old male patient with PSS managed by the multidisciplinary team of thoracic oncology. The therapeutic plan comprised surgery, chemotherapy, stereotactic radiosurgery and targeted therapy, with excellent results. MATERIALS AND METHODS: Data from 37 cases reported in English during the past 20 years were gathered and analyzed. PSS was found to occur at a mean age of 36±17.082 (range=13-67) years. Survival analysis was performed on 20 cases with follow-up of at least 6 months. CONCLUSION: Only complete resection of the tumor seems to be an independent prognostic factor. To our knowledge, this is the first report on the safety and effectivity of pazopanib in PSS and may provide guidance for similar cases in the future.

Primary cardiac synovial sarcoma: A review correlating outcomes with surgery and adjuvant therapy.

BACKGROUND: Cardiac synovial sarcoma (CSS) is an extremely rare malignant tumor with a severe prognosis, due to frequent relapses and metastases. To obtain useful information for treatment protocols, we analyzed survival and therapy data from the cases reported in the literature. METHODS: A search of MEDLINE was performed throughout December 2018. Using key words relating to primary CSS, we collected from the literature a total of 97 cases, mainly consisting of single case reports. To identify predictors of overall survival, statistical analyses were performed on a selected cohort of 55 patients for whom relevant clinicopathological data were available, including surgery and adjuvant therapy. RESULTS: The univariable analysis revealed that patients in their first three decades of life have better overall survival. The univariable analysis also showed that patients not receiving adjuvant chemotherapy are at increased risk of death. In the multivariable analysis, tumor resection and chemotherapy are factors significantly improving overall survival. CONCLUSION: The survival of patients with CSS is positively influenced by a young patient's age and greatly improved by the administration of chemotherapy, even in the absence of tumor resection.

Intracranial synovial sarcoma: A clinical, radiological and pathological study of 16 cases.

INTRODUCTION: Synovial sarcoma (SS) is a tumor of unknown origin and is extremely rare in the central nervous system. Most studies on intracranial SS included only one or two cases. To better understand the disease, we review a series of primary intracranial SS. METHOD AND MATERIALS: 16 primary intracranial SS in Tiantan Hospital during 2008-2017 were included. The clinical characteristics, including radiological and histological examination, operative records, and prognoses were reviewed. RESULT: The case series included nine male and seven female patients with an average age of 23.8 years. Radiological results showed that the supratentorial region (81.25%) was the most common site of the brain involved. All patients were misdiagnosed as non-SS tumors. Gross total resection (GTR) was achieved in 12 cases (75.0%), and subtotal resection (STR) was achieved in 4 cases. All cases showed the characteristic SYT-SSX fusion gene, as detected by RT-PCR. The mean progression-free survival time (PFS) was 10.0 months and the mean overall survival time (OS) was 15.5 months. Multivariate analysis revealed that GTR and postoperative adjuvant radiotherapy were independent factors for PFS (HR = 6.143, 95% CI = 1.491-25.312; P = 0.012, HR = 6.143, 95% CI = 1.491-25.312; P = 0.012 respectively) and OS (HR = 9.000, 95% CI = 1.627-49.773; P = 0.012, HR = 0.017, 95% CI = 0.001-0.213; P = 0.002 respectively). CONCLUSION: Intracranial SS were more frequently observed in the supratentorial region and in young patients without sex predilection. We recommend adjuvant radiation regardless of the extent of resection. More patients and longer follow-up periods were needed to further elucidate the biological features of intracranial SS.

Localized synovial sarcoma: A single institutional study of 191 patients with a minimum follow-up of 5 years for survivors.

PURPOSE: Factors affecting long-term outcomes of synovial sarcoma (SS) remain unknown. Here, we aimed to investigate the long-term oncological outcomes and prognostic factors in a large group of patients with surgically-treated localized SS. PATIENTS AND METHODS: Between 1980 and 2011, 191 patients (94 males and 97 females) were treated at a single hospital with a minimum follow-up of 5 years for survivors. The median age was 35 years (range, 3-80 years), and the median follow-up period was 83 months (range, 3-235 months). RESULTS: Disease-specific survival was 76.4% and 60.4% at 5 and 10 years, respectively. Local recurrence occurred in 23 patients at a median of 33 months (range, 6-158 months), and metastasis occurred in 73 patients at a median of 20 months (range, 2-166 months). In multivariate analysis, grade 3 tumors sized ≥5 cm were significantly associated with worse survival. Ten patients (5.2%) developed metastasis more than 5 years after surgery. CONCLUSION: Tumor size and grade govern prognosis in surgically-treated localized SS in long-term settings. If adequately treated patients have not developed metastases for 5 years after surgery, the risk of subsequently developing metastases was lower than previously reported.