Outcomes of brain metastasis in high-grade bone and soft tissue sarcoma: An analysis of clinicopathological characteristics and survival data

An Evaluation of Risk Factors for Intracranial Metastases of Sarcomas: A Systematic Review and Meta-Analysis

INTRODUCTION

Sarcomas, a group of neoplasms comprising both tissue and bone soft tissue tumors, has an increasing prevalence in recent years. Prognosis significantly hinges on early detection, and if not detected early, may consequently metastasize. This review will be the first systematic review and meta-analysis characterizing the presentation and progression of brain metastases from bone and soft tissue cancers.

METHODS

The PubMed, Scopus, and Web of Science databases were queried to identify studies reporting the incidence of intracranial brain metastases from primary sarcoma to the present. Abstract and full-text screening of 1822 initial articles returned by preliminary search yielded 28 studies for inclusion and data extraction. Qualitative assessment of the studies was conducted in accordance with the Newcastle-Ottawa Scale criteria. Meta-analyses were applied to assess risk factors on outcomes.

RESULTS

The average age within the cohort was 27.9 years with a male and female prevalence of 59.1% and 40.9%, respectively. The odds ratio for living status (dead/alive) was calculated for several risk factors - male/female [OR 1.14, 95% CI 0.62, 2.07], single/multiple metastases [OR 0.67, 95% CI 0.35, 1.28], lung metastases/not [OR 1.63, 95% CI 0.85, 3.13], surgery/no surgery [OR 0.49, 95% CI 0.20, 1.21]. The standardized mean differences for duration from diagnoses to metastases were likewise analyzed - male/female [SMD 0.13, 95% CI -0.15, 0.42], single/multiple metastases [SMD 0.11, 95% CI -0.20, 0.42], lung metastases/not [SMD -0.03, 95% CI -0.38, 0.32], surgery/no surgery [SMD 0.45, 95% CI -0.18, 1.09]. The standardized mean differences for duration from metastases to death were analyzed - lung metastases/not [SMD 0.43, 95% CI -0.08, 0.95].

CONCLUSIONS

Our study observed no statistically significant differences in mortality rate among several patient risk factors. Consequentially, there lacks a clear answer as to whether or not an association between mortality rates exists with these patient factors. As such, it is important to continue research in brain-metastasizing sarcomas despite their relative rarity.

A Rare Case of Spindle Cell Sarcoma With Rare Asymptomatic Cerebellar Metastasis

Sarcomas are one of the rarest cancers, occurring in less than 1% of all adult malignancies. Spindle cell sarcomas are one subset of soft tissue sarcomas that are even less commonly reported in the literature due to the scarcity of cases, especially with the presence of brain metastases. We present a case of an adult male who presented with non-specific exertional dyspnea and chest pain, which was found to have spindle cell sarcoma with cerebellar metastasis.

A rare non-gadolinium enhancing sarcoma brain metastasis with microenvironment dominated by tumor-associated macrophages

Brain metastases occur in 1% of sarcoma cases and are associated with a median overall survival of 6 months. We report a rare case of a brain metastasis with unique radiologic and histopathologic features in a patient with low grade fibromyxoid sarcoma (LGFMS) previously treated with immune checkpoint inhibitor (ICI) therapy. The lone metastasis progressed in the midbrain tegmentum over 15 months as a non-enhancing, T2-hyperintense lesion with peripheral diffusion restriction, mimicking a demyelinating lesion. Histopathology of the lesion at autopsy revealed a rich infiltrate of tumor-associated macrophages (TAMs) with highest density at the leading edge of the metastasis, whereas there was a paucity of lymphocytes, suggestive of an immunologically cold environment. Given the important immunosuppressive and tumor-promoting functions of TAMs in gliomas and carcinoma/melanoma brain metastases, this unusual case provides an interesting example of a dense TAM infiltrate in a much rarer sarcoma brain metastasis.

Brain metastases of sarcoma: a rare phenomenon in rare tumours

The usual site for distant metastases of sarcoma is lungs, while brain metastasis (BM) occurs much less frequently and usually late in the disease progression. Despite the advancement in cancer treatment, the outcome for patients with brain metastasis is poor, and their lifespan is short. The frequency of BM in sarcoma seems to be affected by the location and histology of the primary tumour. Sarcoma subtypes with a high propensity for brain metastasis are ASPS, leiomyosarcoma and osteosarcoma. There are no clear guidelines for the treatment of sarcoma brain metastasis. However, therapeutic options include surgery, radiotherapy and chemotherapy, and are often combined. Targeted therapies are a promising treatment option for sarcoma but require investigation in patients with BM. The following review presents the data on sarcoma brain metastasis incidence, treatment and prognosis.

A retrospective analysis of the prognosis of Japanese patients with sarcoma brain metastasis

BACKGROUND

Bone and soft tissue sarcomas are rare tumors and extremely rarely metastasize to the brain. Previous studies have examined the characteristics and poor prognostic factors in cases of sarcoma brain metastasis (BM). Due to the rarity of cases of BM from sarcoma, limited data exist concerning the prognostic factors and treatment strategies.

METHODS

A retrospective single-center study was performed on sarcoma patients with BM. The clinicopathological characteristics and treatment options for BM of sarcoma were investigated to identify predictive prognostic factors.

RESULTS

Between 2006 and 2021, 32 patients treated for newly diagnosed BM at our hospital were retrieved among 3133 bone and soft tissue sarcoma patients via our database. The most common symptom was headache (34%), and the most common histological subtypes were alveolar soft part sarcoma (ASPS) and undifferentiated pleomorphic sarcoma (25%). Non-ASPS (p = 0.022), presence of lung metastasis (p = 0.046), a short duration between initial metastasis, and the diagnosis of brain metastasis (p = 0.020), and the absence of stereotactic radiosurgery for BM (p = 0.0094) were significantly correlated with a poor prognosis.

CONCLUSIONS

In conclusion, the prognosis of patients with brain metastases of sarcomas is still dismal, but it is necessary to be aware of the factors associated with a relatively favorable prognosis and to select treatment options appropriately.

Clinical outcomes of brain metastasectomy from soft tissue and bone sarcomas: a systematic review

BACKGROUND

Brain metastasis in sarcomas is associated with a poor prognosis. Data regarding prognostic factors and clinical outcomes of surgical resection of brain metastasis from sarcomas are limited. The objective of this systematic review was to evaluate survival outcomes post-brain metastasectomy for patients with soft tissue and bone sarcomas.

METHODS

A systematic review was conducted examining survival outcomes among adults and children with soft tissue and bone sarcoma undergoing brain metastasectomy, in the English language from inception up to May 31, 2021. Two reviewers independently evaluated and screened the literature, extracted the data, and graded the included studies. The body of evidence was evaluated and graded according to the Newcastle-Ottawa Quality Assessment Scale for Cohort Studies and the Joanna Briggs Institute Critical Appraisal Checklist for Case Series. Results were synthesized using descriptive methods. A meta-analysis was not possible due to the low quality and heterogeneity of studies.

RESULTS

Ten studies published between 1994 and 2020 were included: three were retrospective cohort studies and seven were case series. 507 patients were included, of whom 269 underwent brain metastasectomy. The median follow-up period ranged between 14 and 29 months. The median survival period after metastasectomy ranged from 7 to 25 months. The most common prognostic factors associated with survival included presenting performance status, age, number of brain metastases, presence of lung metastases, and peri-operative radiation therapy administration.

DISCUSSION

Although the level of evidence is low, retrospective studies support that brain metastasectomy can be performed with reasonable post-operative survival in selected individuals.

Brain Metastases from Adult Sarcomas: A Retrospective Cohort Study from the Hellenic Group of Sarcomas and Rare Cancers (HGSRC)

Brain metastases are rare events in patients with sarcoma and the available information is relatively limited. We retrospectively reviewed medical records of patients with sarcoma who developed brain metastases between April 2010 and April 2020 in six centers. Thirty-four adult patients were included with a median age at brain metastases diagnosis of 55.5 years (range, 18–75). The primary sarcomas originated either from soft tissue (n = 27) or bone (n = 7) and the most common subtypes were leiomyosarcoma (n = 8), Ewing sarcoma/peripheral neuroectodermal tumor (PNET) (n = 7) and osteosarcoma (n = 3). Most primary tumors were of high grade and located mainly in the extremities (n = 18). The vast majority of patients at the time of brain metastasis diagnosis already had extracranial metastatic disease (n = 26). The median time from sarcoma diagnosis to cerebral metastasis diagnosis was 16 months (range, 1–136). Treatment modalities for brain metastatic disease included whole-brain radiation therapy (WBRT) (n = 22), chemotherapy (n = 17), exclusive palliative care (n = 5), surgery (n = 9), targeted therapy (n = 6) or stereotactic radiosurgery (n = 2). Most patients experienced a progression of brain metastases (n = 11). The median overall survival from brain metastasis diagnosis was 3 months (range, 0–80). OS was significantly influenced by time-to-brain metastases (p = 0.041), WBRT (p = 0.018), surgery (p = 0.002) and chemotherapy (p = 0.006). In a multivariate analysis, only the localization of the primary (p = 0.047) and WBRT (p = 0.038) were associated with survival with statistical significance. Patients with sarcoma brain metastases have a particularly poor prognosis and an appropriate therapeutic approach is yet to be defined.