Lack of ErbB-2 oncogene product overexpression in soft tissue sarcomas

The importance of hormone receptor analysis in osteosarcoma cells growth submitted to treatment with estrogen in association with thyroid hormone

Bone tumor incidence in women peaks at age 50-60, coinciding with the menopause. That estrogen (E2) and triiodothyronine (T3) interact in bone metabolism has been well established. However, few data on the action of these hormones are available. Our purpose was to determine the role of E2 and T3 in the expression of bone activity markers, namely alkaline phosphatase (AP) and receptor activator of nuclear factor kappaB ligand (RANKL). Two osteosarcoma cell lines: MG-63 (which has both estrogen (ER) and thyroid hormone (TR) receptors) and SaOs-29 (ER receptors only) were treated with infraphysiological E2 associated with T3 at infraphysiological, physiological, and supraphysiological concentrations. Real-time RT-PCR was used for expression analysis. Our results show that, in MG-63 cells, infraphysiological E2 associated with supraphysiological T3 increases AP expression and decreases RANKL expression, while infraphysiological E2 associated with either physiological or supraphysiological T3 decreases both AP and RANKL expression. On the other hand, in SaOs-2 cells, the same hormone combinations had no significant effect on the markers' expression. Thus, the analysis of hormone receptors was shown to be crucial for the assessment of tumor potential growth in the face of hormonal changes. Special care should be provided to patients with T3 and E2 hormone receptors that may increase tumor growth.

Prognostic and therapeutic relevance of HER2 expression in osteosarcoma and Ewing's sarcoma

Expression of HER2 was evaluated by immunohistochemical techniques in 84 osteosarcoma (OS) and 113 Ewing's sarcoma (ES) paraffin-embedded tumour biopsies. HER2 gene status was also assessed in a panel of cell lines as well as in vitro efficacy of trastuzumab (a humanised antibody directed against HER2) as single agent or in combination with the insulin-like growth factor I receptor (IGF-IR) IR3 antibody. Overexpression of HER2 was present in 32% of OS and 16% of ES and was significantly associated with the increased expression of P-glycoprotein, a surface molecule responsible for multidrug resistance. Event-free survival analyses revealed a prognostic value for HER2 and/or P-glycoprotein expression in OS, but not in ES. However, despite its prognostic relevance, no therapeutic effectiveness was observed pre-clinically for trastuzumab-driven therapy, in both OS or ES cell lines, unless the antibody was associated with anti-IGF-IR targeting strategies. Therefore, the therapeutic potential of trastuzumab in these neoplasms may be better exploited in combined treatments with anti-IGF-IR approaches.

C-erb-B2 (HER2/neu) expression in synovial sarcoma of the head and neck

BACKGROUND

Synovial sarcoma is a malignant mesenchymal tumor composed of varying proportions of spindle and epithelial cell components. Because of the histologic and immunohistochemical similarity of synovial sarcoma to epithelial carcinomas, we hypothesized that the human epithelial growth factor receptor 2 (C-erb-B2, also termed HER2/neu) may contribute to the tumor phenotype and provide a new therapeutic target for this soft tissue tumor.

METHODS

Three head and neck, one chest wall, and seven extremity synovial sarcomas were evaluated for C-erb-B2 (HER2/neu) expression by immunohistochemistry, Western immunoblotting, and fluorescence in situ hybridization (FISH).

RESULTS

The head and neck cases demonstrated immunohistochemically strong positive staining, whereas tumors from other anatomic locations showed neither positive nor cytoplasmic restricted staining. Antigen-targeted antibody therapy (trastuzumab) was initiated in two patients.

CONCLUSIONS

These results demonstrate that C-erb-B2 (HER2/neu) may play a role in the tumorigenesis of synovial sarcoma; and, therefore, antigrowth factor therapies may provide a previously unrecognized pharmaceutical approach to soft tissue tumors. The data also suggest that although synovial sarcoma of the head and neck and synovial sarcoma of the extremities have similar morphologic features, they may be clinically and mechanistically distinct entities.

Expression of epidermal growth factor receptor,ERBB2 andKIT in adult soft tissue sarcomas

BACKGROUND

Little is known about the expression of receptor tyrosine kinases in adult soft tissue sarcomas (STS). In the current study, the authors analyzed the expression of epidermal growth factor receptor (EGFR), ERBB2, and KIT in 281 patients with STS who were treated in a single institution. Verification of the presence of an association with prognosis was performed.

METHODS

The current study included 281 adult patients with STS of the extremity and trunk who were diagnosed and treated in the National Cancer Center, Tokyo. Expression was assessed using immunohistochemical stains for EGFR, ERBB2, and KIT on formalin-fixed, paraffin-embedded tissue sections by standard avidin-biotin peroxidase complex technique and EGFR detection system.

RESULTS

Positive staining of EGFR was observed in 168 of 281 (60%) patients. Positive staining was common in pleomorphic malignant fibrous histiocytomas (89%), myxofibrosarcomas (89%), synovial sarcomas (76%), malignant peripheral nerve sheath tumors (89%), and leiomyosarcomas (73%). It was less common in well differentiated liposarcomas (38%), fibrosarcomas (36%), and myxoid liposarcomas (6%). In contrast, positive staining of ERBB2 and KIT was very limited. Increased levels of EGFR were significantly associated with a decreased probability of overall survival (P = 0.01), although by univariate analysis; probability of overall survival at 5 years was 64% in patients with increased levels of EGFR and 79% in patients without such overexpression. The overexpression of EGFR was significantly associated with histologic grade (P < 0.001). Moreover, stratified log-rank test revealed that there is an interrelation between EGFR overexpression and histologic grade.

CONCLUSIONS

EGFR overexpression was found to be a negative prognostic factor of adult STS, which is strongly associated with histologic grade. STS patients with EGFR overexpression may benefit from treatment with currently available biospecific inhibitors for EGFR.