Immune Surveillance Plays a Role in Locally Aggressive Giant Cell Lesions of Bone

The giant cell tumor during pregnancy: A review of literature

BACKGROUND

Giant cell tumors (GTC) of bone are benign, locally aggressive tumors generally occurring in young people with a female predominance during reproductive age. Considering their worsening during pregnancy it has been suggested that pregnancy can accelerate GCT progression or favor recurrence but correlation between tumor growth and pregnancy has not yet been clarified. Aim of this study was to clarify clinical characteristics, timing and type of treatment through a literature review on GTCs occurring during pregnancy.

PATIENTS AND METHODS

An electronic search was performed in December 2020 in PubMed, Scopus, Embase, Medline, Cochrane Register using the keywords "giant cell tumor" AND "pregnancy" looking for papers reporting cases of giant cell tumors of the bone onset or recurred during pregnancy. The electronic search identified 212 papers; sixteen studies were selected, for a total of 32 cases.

RESULTS

The diagnosis was made during pregnancy in 24 cases and after the partum in 8 cases. 27 cases were new diagnoses while 5 cases were recurrences. Pulmonary metastases were reported in 3 patients. The treatment was performed during the pregnancy in 7 out of 32 cases; in the remaining 27 cases treatment was performed after delivery. The hormone receptor status was reported in 14 patients. Data regarding follow-up was reported for 26 out of 32 patients; three patients had local recurrences that were treated with wide resection and amputation in 2 and 1 case, respectively; at the last follow-up all patients were apparently without any evidence of disease except for three patients who had stable lung metastases.

DISCUSSION

In case of GCT during pregnancy, a multidisciplinary approach is necessary to offer the patients the best treatment in terms of mother and child's health. A correct diagnosis is necessary and not confusing tumor symptoms with ones of pregnancy is mandatory in order not to delay the diagnosis and let the tumor progress. Actually, even though pregnancy would seem to promote GCT growth and aggressiveness, the relationship is not clear. More studies are necessary to clarify this interesting aspect.

LEVEL OF EVIDENCE

IV, systematic review.

Sclerostin immunohistochemical staining in surgically treated giant cell tumor of bone

BACKGROUND

Giant cell tumor of bone (GCTB) is a destructive lesion with a high potential for recurrence. RANK-ligand targeted therapy has provided promising, yet mixed results. Sclerostin (SOST) inhibition results in a net anabolic response and is currently used in the treatment of osteoporosis. The application to GCTB is unknown.

OBJECTIVES

We sought to determine if GCTB stained for SOST on immunohistochemistry and correlate its expression with predictor variables.

METHODS

All patients at a single institution undergoing surgery for GCTB between 1993 and 2008 with a minimum of 6 months follow-up were included. Primary outcomes included the presence of SOST staining, secondary outcomes included the correlation of patient and tumor-specific predictor variables.

RESULTS

SOST antibody staining of any cell type was present in 47 of 48 cases (97.9%). Positivity of the stromal cells was present in 39 of 48 cases (81.3%) and was associated with radiographic aggressiveness (p = 0.023), symptomatic presentation (p = 0.032), prior surgery (p = 0.005), and patient age (p = 0.034). Positivity of giant cells was present in 41 of 48 cases (85.4%) and was not significant with predictive factors.

CONCLUSIONS

Sclerostin staining in GCTB is a novel finding and warrants further research to define the role of sclerostin as a prognostic factor and therapeutic target.

Sclerostin Immunohistochemical Staining in Aggressive Maxillofacial Giant Cell Lesions: Initial Results and Potential Therapeutic Target

INTRODUCTION

Maxillofacial (MF) giant cell lesions (GCLs) are benign, often locally aggressive lesions with potential for recurrence. Systemic treatments have included interferon alpha, calcitonin, bisphosphonates, and denosumab. Sclerostin (SOST) is typically thought to be a negative regulator of bone metabolism and anti-SOST agents have been used to treat osteoporosis; however, its role in central giant cell granuloma is unknown. The purpose of this study was to evaluate the expression of SOST in MF GCLs.

MATERIALS AND METHODS

This was a retrospective study of patients with MF GCLs treated at a single institution between 1993 and 2008 with a minimum follow-up of 6 months. Representative tissue was used to create a tissue microarray and SOST immunohistochemical (IHC) staining and grading was performed. The primary outcomes were IHC staining of the stromal cells and giant cells. The secondary outcomes included correlation of IHC staining and patient predictor variables including clinically benign and aggressive lesions. All analyses were completed using univariate statistical tests.

RESULTS

A total of 37 subjects were included (29 clinically aggressive and 8 clinically benign). Sclerostin staining was present in 30 of 37 subjects (81%). Of these, 22 (60%) had stromal cell staining and 28 (76%) had giant cell staining. The presence or absence of staining, of either cell type, was not associated with aggressiveness, presence of clinical symptoms, tumor size, previous interferon therapy, previous surgery, or the race or age of the patient.

DISCUSSION

Maxillofacial GCLs have an overall high level of SOST staining; however, the role of SOST in treatment and prognosis is unknown and warrants further study.

Advances in immunotherapeutic targets for childhood cancers: A focus on glypican-2 and B7-H3

Cancer immunotherapies have revolutionized how we can treat adult malignancies and are being translated to pediatric oncology. Chimeric antigen receptor T-cell therapy and bispecific antibodies targeting CD19 have shown success for the treatment of pediatric patients with B-cell acute lymphoblastic leukemia. Anti-GD2 monoclonal antibody has demonstrated efficacy in neuroblastoma. In this review, we summarize the immunotherapeutic agents that have been approved for treating childhood cancers and provide an updated review of molecules expressed by pediatric cancers that are under study or are emerging candidates for future immunotherapies. Advances in our knowledge of tumor immunology and in genome profiling of cancers has led to the identification of new tumor-specific/associated antigens. While cell surface antigens are normally targeted in a major histocompatibility complex (MHC)-independent manner using antibody-based therapies, intracellular antigens are normally targeted with MHC-dependent T cell therapies. Glypican 2 (GPC2) and B7-H3 (CD276) are two cell surface antigens that are expressed by a variety of pediatric tumors such as neuroblastoma and potentially can have a positive impact on the treatment of pediatric cancers in the clinic.

The Relationship Between Tumor-Stroma Ratio, the Immune Microenvironment, and Survival in Patients With Spinal Chordoma

BACKGROUND

Currently, little is known about the clinical relevance of tumor-stroma ratio (TSR) in chordoma and data discussing the relationship between TSR and immune status of chordoma are lacking.

OBJECTIVE

To characterize TSR distribution in spinal chordoma, and investigated its correlation with clinicopathologic or immunological features of patients and outcome.

METHODS

TSR was assessed visually on hematoxylin and eosin-stained sections from 54 tumor specimens by 2 independent pathologists. Multiplex immunofluorescence was used to quantify the expression levels of microvessel density, Ki-67, Brachyury, and tumor as well as stromal PD-L1. Tumor immunity status including the Immunoscore and densities of tumor-infiltrating lymphocytes (TILs) subtypes were obtained from our published data and reanalyzed.

RESULTS

Bland-Altman plot showed no difference between mean TSR derived from the two observers. TSR was positively associated with stromal PD-L1 expression, the Immunoscore and CD3+ as well as CD4+ TILs density, but negatively correlated with tumor microvessel density, Ki-67 index, surrounding muscle invasion by tumor and number of Foxp3+ and PD-1+ TILs. Low TSR independently predicted poor local recurrence-free survival and overall survival. Moreover, patients with low TSR and low Immunoscore chordoma phenotype were associated with the worst survival. More importantly, combined TSR and Immunoscore accurately reflected prognosis and enhanced the ability of TSR or Immunoscore alone for outcome prediction.

CONCLUSION

These data reveal the significant impact of TSR on tumor progression and immunological response of patients. Subsequent use of agents targeting the stroma compartment may be an effective strategy to treat chordoma especially in combination with immune-based drugs.

B7-H3 and its role in bone cancers

Most bone cancers have a high risk of metastasis, recurrence, and poor prognosis. Although conventional treatments are still the most important therapy, disadvantages still exist. Therefore, there is an unmet need to develop effective strategies. Immunotherapy is a promising therapy. Immunotherapies targeting checkpoints have proven to be successful, but B7-H3 (CD276, clusters of differentiation protein 276), a member of the B7-family of co-stimulatory molecules, is not being widely studied in bone cancers. This review summarized the studies on B7-H3 in bone cancers. 4 studies investigated B7-H3 expression in osteosarcoma, but there is no study on B7-H3 expression in chondrosarcoma. Two studies investigated the possibility to treat Ewing`s sarcoma through targeting the B7-H3 CAR (chimeric antigen receptors) T-cells or using anti-B7-H3 antibody. A study observed the growth of myeloma in B7-H3-deficient mice and the therapeutic effect of B7-H3 antibody and a study invested B7-H3 expression in myeloma patients. One study reported B7-H3 expression in osteoclastomas and one study investigated B7-H3 expression in chordoma tumor tissues. Two clinical trials are conducting on the therapy of osteosarcoma and myeloma using B7-H3 as a target. In conclusion, B7-H3 could be a target of bone cancers.

Profiling targetable immune checkpoints in osteosarcoma

Osteosarcomas are aggressive bone tumors for which therapeutic advances have not improved over several decades. Unlike most pediatric tumors, the osteosarcoma genome is remarkably unstable, characterized by numerous copy number alterations and chromosomal structural aberrations. In this study, we asked if the targetable immune checkpoints CD274 (PD-L1), PDCD1LG2 (PD-L2), CD276 (B7-H3) and IDO1 are impacted by copy number alterations in osteosarcoma. Of the 215 osteosarcoma samples investigated, PD-L1/PD-L2, B7-H3 and IDO1 were independently gained at frequencies of approximately 8-9%, with a cumulative frequency of approximately 24%. RNA sequencing data from two independent cohorts revealed that B7-H3 is the most highly expressed immune checkpoint gene among the four investigated. We also show that IDO1 is preferentially expressed in pediatric solid tumors and that increased protein expression of B7-H3 and IDO1 are significantly associated with inferior survival in patient samples. Using human osteosarcoma cell lines, we demonstrate that IDO1 is gained in MG63 and G292 cells and that the IDO1 inhibitor, epacadostat, inhibits the enzymatic activity of IDO1 in a dose-dependent manner in these cells. Together, these data reveal the genomic and transcriptomic profiles of PD-L1, PD-L2, B7-H3 and IDO1 in osteosarcoma and identifies a potential context for targeted immunotherapeutic intervention in a subset of patients.

STAT1, IGF1, RAC1, and MDM2 Are Associated with Recurrence of Giant Cell Tumor of Bone

BACKGROUND

In our previous study, mouse double minute 2 homolog (MDM2), insulin-like growth factor 1 (IGF1), signal transducer and activator of transcription 1 (STAT1), and Rac family small GTPase 1 (RAC1) were correlated with the recurrence of giant cell tumor of bone (GCT). The aim of this study is to use a large cohort study to confirm the involvement of these four genes in GCT recurrence.

METHODS

The expression of these four genes was detected and compared between GCT patients with or without recurrence. The correlation between the expression of these four genes and clinical characteristics was evaluated. Protein-protein interaction (PPI) network was constructed for functional enrichment analysis.

RESULTS

It showed that the expression levels of MDM2, IGF1, STAT1, and RAC1 in GCT patients with recurrence were significantly higher than those in GCT patients without recurrence (P < 0.05). Multivariate logistic regression analysis suggested that several clinical characteristics may influence prognosis. A PPI network was constructed using the four genes as hub genes. Functional enrichment analysis showed that this network involves many important biological progress mediated by these four genes, including immune response.

CONCLUSION

MDM2, IGF1, STAT1, and RAC1 are associated with GCT recurrence, which might serve as biomarkers for GCT recurrence.