Osteosarcoma. Clinical features and evolving surgical and chemotherapeutic strategies

Arnicolide D Inhibits Proliferation and Induces Apoptosis of Osteosarcoma Cells through PI3K/Akt/mTOR Pathway

BACKGROUND

Osteosarcoma is considered as the most prevalent form of primary malignant bone cancer, prompting a pressing need for novel therapeutic options. Arnicolide D, a sesquiterpene lactone derived from the traditional Chinese herbal medicine Centipeda minima (known as E Bu Shi Cao in Chinese), showed anticancer efficacy against several kinds of cancers. However, its effect on osteosarcoma remains unclear.

OBJECTIVE

This study aimed to investigate the anticancer activity of arnicolide D and the underlying molecular mechanism of its action in osteosarcoma cells, MG63 and U2OS.

METHODS

Cell viability and proliferation were evaluated through MTT assay and colony formation assay following 24 h and 48 h treatment with different concentrations of arnicolide D. Flow cytometry was employed to examine cell cycle progression and apoptosis after 24 h treatment of arnicolide D. Western blotting was performed to determine the expression of the PI3k, Akt and m-TOR and their phosphorylated forms.

RESULTS

Our findings revealed that arnicolide D treatment resulted in a significant reduction in cell viability, the inhibition of proliferation, and the induction of apoptosis and cell cycle arrest in the G2/M phase. Furthermore, arnicolide D could inhibit the activation of PI3K/Akt/mTOR pathway in osteosarcoma cells.

CONCLUSION

Based on our results, arnicolide D demonstrated significant anti-osteosarcoma activity and held the potential to be considered as a therapeutic candidate for osteosarcoma in the future.

Hyperthermic Isolated Limb Perfusion with TNF alpha and Cisplatin in the Treatment of Osteosarcoma of the Extremities: A Feasibility Study in Healthy Dogs

Purpose. The feasibility of hyperthermic isolated limb perfusion (HILP) with tumor necrosis factor-alpha (TNFalpha ) and cisplatin for the management of osteosarcoma was studied in the canine model.Methods. During seven perfusions in six healthy mongrel dogs (weight 32+/-2 kg) technical aspects of HILP under mild hyperthermia (39- 40) were studied. In five experiments HILP was performed with TNFalpha alone (0.5 mg/l extremity volume), and in two experiments TNFalpha was combined with cisplatin (25 mg/l extremity volume). During the perfusions physiological parameters were monitored and TNFalpha and total cisplatin concentrations were determined.Results. Perfusion conditions (pH, PCO(2) , PO(2), flow and pressure) remained within physiological ranges.Three dogs died within 24 h despite a sublethal systemic concentration of TNFalpha that leaked from the perfusion circuit. Three dogs were terminated; one dog after the second experiment in accordance with Dutch ethical rules; one dog showed an invagination of the small bowel resulting in an ileus; one dog because of necrosis of the perfused limb.Conclusions. This feasibility study in healthy dogs demonstrated that HILP with TNFalpha and cisplatin was associated with a high mortality rate and does not allow us to treat dogs with spontaneous osteosarcoma with TNFalpha and cisplatin HILP. Therefore, an alternative model should be used in the search for the ideal combination of perfusion agents for limb sparing treatment in human osteosarcoma.

Strategies for the targeted delivery of therapeutics for osteosarcoma

BACKGROUND

Conventional therapy for osteosarcoma has reached a plateau of 60 - 70%, a 5-year survival rate that has changed little in two decades, highlighting the need for new approaches.

OBJECTIVE

To review the alternative means of delivering effective therapy for osteosarcoma that reach beyond the central venous catheter.

METHODS

Drawing on the author's own experiences providing care to high-risk osteosarcoma patients and reviewing the last two decades of literature describing sarcoma therapy, available information is summarized about potential osteosarcoma treatments that deliver therapy by a less conventional route.

RESULTS/CONCLUSIONS

Intra-arterial chemotherapy has a limited impact on survival, but may help to achieve a better limb salvage. Intrapleural chemotherapy is important for managing malignant effusions. The development of inhalation therapies, treatments that target new bone formation such as bisphosphonates, chemically targeted radiation and antibody-based therapies all have potential to improve osteosarcoma therapy.

Fibular osteosarcomas: contaminated margins may not impact survival

The fibula is an expendable bone which when affected by primary malignancy may simplify treatment and improve outcome. This concept was questioned previously in a study showing a high rate of inadequate margins at surgical resection. We asked whether margin status and other dependent variables affect survival. We analyzed the charts of 36 patients with fibular osteosarcomas treated from 1919 to 2000. We estimated survival by the Kaplan-Meier method and the prognostic significance of dependent variables, especially marginal status, with univariate association using Cox proportional hazard regression. The survival of patients with fibular osteosarcomas was limited, with a median survival of 5 years 4 months after diagnosis. At 5 years, 16 patients died of their disease. Sixteen patients were still alive at 10 years followup. The margin status at surgery was not associated with survival. A higher tumor grade at diagnosis, surgical treatment with above-knee amputation, and occurrence of metastasis were associated with poorer long-term survival. The survival of patients with fibular osteosarcomas was not better than with osteosarcomas arising in other locations. A marginal resection surprisingly did not impact on overall survival, although we had a limited dataset and heterogeneous treatment protocols.

Essential erbB family phosphorylation in osteosarcoma as a target for CI-1033 inhibition

BACKGROUND

The role of erbB tyrosine kinases, especially Her-2, in osteosarcoma has engendered intense debate. Some investigators identified an association between low-level Her-2 expression, compared to none, and poor patient outcome. Others questioned the importance of apparent cytoplasmic expression of Her-2, since membranous overexpression is associated with poor outcome in carcinomas. We previously demonstrated that primary osteosarcoma cells express cell-surface EGFR and Her-2, with the p80 isoform of Her-4 localized to the nucleus. We wished to determine if erbB kinases in osteosarcoma were phosphorylated, and if this was required for growth.

PROCEDURES

We cultured early passage osteosarcoma cell lines in the presence or absence of the pan-erbB inhibitor CI-1033 and examined the phosphorylation status of EGFR, Her-2, and Her-4 by immunohistochemistry, cell-based ELISA, flow cytometry and two dimensional Western blot. We also assessed the impact of CI-1033 upon osteosarcoma growth and survival in vitro.

RESULTS

EGFR, Her-2, and Her-4 were constitutively phosphorylated in early passage osteosarcoma cells cultured in vitro. CI-1033 abrogated erbB receptor phosphorylation and caused growth inhibition and apoptosis in a titratible fashion with concentrations of 1 muM or more.

CONCLUSIONS

EGFR, Her-2, and Her-4 are constitutively phosphorylated in early passage osteosarcoma cells in tissue culture, and erbB signaling provides essential growth and anti-apoptotic signals to osteosarcoma cells. This suggests that erbB overexpression is not required for erbB to promote malignancy, but rather that overexpression is one of several mechanisms that generate unregulated erbB signaling.

Cell surface expression of epidermal growth factor receptor and Her-2 with nuclear expression of Her-4 in primary osteosarcoma

There is controversy over the role of Her-2 in osteosarcoma, with some investigators reporting association between expression and adverse outcome, whereas others point to the lack of gene amplification and membranous expression by immunohistochemistry (IHC) as inconsistent with biological significance. Her-2 normally requires pairing with epidermal growth factor receptor (EGFR), Her-3, or Her-4, but these have been less well studied in osteosarcoma. We evaluated the expression of each of these receptors in osteosarcoma and their potential to contribute to pathogenesis by examining a panel of low-passage primary osteosarcoma cell lines, comparing these with archival tumor specimens. Her-2 immunoreactivity was seen frequently in the diffuse staining pattern described previously. We observed EGFR in all samples by IHC. Her-3 expression was not observed. Her-4 expression was nuclear in distribution in all tumor samples and many cell line samples, consistent with activation and cleavage of the receptor. Quantified expression of Her-2 and EGFR mRNA by quantitative, real-time PCR in cell lines correlated with IHC for Her-2 but not for EGFR. Western blot identified full-length receptors for EGFR and Her-2 in all expected cell lines and showed Her-4 to be predominantly in the p80 form. Flow cytometry identified cell surface Her-2 and EGFR in all lines with receptor expression by IHC. We conclude that the cell surface expression of Her-2 and EGFR and the nuclear localization of the activated p80 fragment of Her-4 suggest that all three may be contributing to osteosarcoma pathogenesis. Therapy directed against this family of receptors may be beneficial for patients with osteosarcoma.

Inhibition of MMP-1 expression by antisense RNA decreases invasiveness of human chondrosarcoma

We previously reported that an elevated level of matrix metalloproteinase-1 (MMP-1) gene expression in patients with chondrosarcoma has a strong statistical correlation with recurrence and in vitro invasion. In the present study, we used an antisense RNA strategy for MMP-1 inhibition to determine if this would affect the invasive characteristics of the cells. We transfected a human chondrosarcoma cell line with a retroviral plasmid expressing a 770 bp genomic fragment of the human MMP-1 gene in the sense or antisense orientation. The results show that cells transfected with the MMP-1 antisense fragment had a significant decrease in both MMP-1 protein and enzyme activity (p<0.05) as compared to cells transfected with an empty plasmid or the parental cells. Cells transfected with the MMP-1 antisense fragment demonstrated a significant decrease in their ability to invade the collagen I barrier (p<0.05). The gene expression for MMP-8 and MMP-13 were unaffected in cells transfected with the MMP-1 antisense fragment, MMP-1 sense fragment, or empty plasmid. These results support the hypothesis that MMP-1 facilitates tumor cell egress from chondrosarcoma tissue and demonstrate the potential of MMP-1 as a promising target for a novel biologic therapy in chondrosarcoma.

Adjuvant chemotherapy for osteosarcoma may not increase survival after neoadjuvant chemotherapy and surgical resection

BACKGROUND AND OBJECTIVES

Osteosarcoma is a primary malignancy of bone. Current therapy includes neoadjuvant chemotherapy, surgery, and postoperative (adjuvant) chemotherapy. Prolonged treatment with chemotherapeutic agents may place patients at increased risk for complications including secondary malignancy. The authors have had promising results with neoadjuvant therapy and surgery alone in the treatment of osteosarcoma. This study retrospectively examines neoadjuvant therapy and surgery alone for the treatment of primary osteosarcoma of bone with no evidence of distant metastases.

METHODS

Fifty-four patients, with localized osteosarcoma of bone received neoadjuvant therapy followed by definitive surgical resection. Thirty-five patients received chemotherapy after surgery (adjuvant group) and nineteen patients were followed without postoperative chemotherapy (no adjuvant group).

RESULTS

Tumor necrosis was predictive of survival. Kaplan-Meier analysis revealed the use of postoperative chemotherapy was not a predictor of improved outcome. Four patients in the adjuvant therapy group died of secondary malignancy compared with none of the no adjuvant therapy group. Patient age, sex, race, and tumor location were not predictive of survival.

CONCLUSIONS

The use of adjuvant chemotherapy in the treatment of localized osteosarcoma of bone did not increase survival after neoadjuvant therapy and definitive surgical therapy. Instead, there was an increased incidence of secondary malignancy after its use.

Osteosarcoma: oncologic and functional results. A single institutional report covering 22 years

BACKGROUND AND OBJECTIVES

The oncologic and functional results in patients treated because of osteosarcoma (OS) were evaluated.

METHODS

Fifty-one patients with high-grade OS were treated between 1974 and 1996 at our hospital. All patient records were studied, and the surviving patients were evaluated according to the American Musculoskeletal Tumor Society functional rating system. The majority of patients received adjuvant chemotherapy (prior to 1983) or neoadjuvant chemotherapy (from 1983). Until 1987, all patients with extremity OS had ablative surgery; from 1987, the majority had limb-saving surgery. Lung metastases were resected in most cases.

RESULTS

Overall 2-year and 5-year disease-free survival (DFS) rates were 27 of 51 and 16 of 42, respectively. Patients with vertebral or pelvic OS or contaminated margins after resection had a very bad outcome. In all other subgroups, including patients with various types of chemotherapy, response to chemotherapy, diameter of tumor, presence or absence of metastatic spread, and location of tumor, a 5-year DFS of about 50% was found. Recurrent disease in patients who had achieved a 2-year disease-free interval was relatively low (4/23 patients).

CONCLUSIONS

Survival in our series was worse than in most other studies. A very bad outcome was found in patients with vertebral or pelvic OS or with contaminated margins after resection.

Magnetic resonance imaging of the musculoskeletal system. Part 9. Primary Tumors

Magnetic resonance imaging, because of its exquisite soft tissue contrast, has dramatically improved the ability to preoperatively stage primary osseous and soft tissue neoplasms. This technique also has allowed the monitoring of the effects of chemotherapy and the screening for recurrence of neoplasms. The role of magnetic resonance imaging in the preoperative evaluation of the patient with a suspected primary osseous or soft tissue neoplasm is outlined, instances where magnetic resonance imaging potentially may make a specific diagnosis are outlined, the importance of gadolinium enhancement as an adjunct to native magnetic resonance imaging is stressed, and an algorithm for followup of patients after chemotherapy or definitive surgical treatment is presented. In all cases, the magnetic resonance images should be correlated with the plain film, which is still an important aspect of the diagnosis of osseous lesions.

A phase II trial of high-dose methotrexate in previously untreated children and adolescents with high-risk unresectable or metastatic rhabdomyosarcoma

PURPOSE

The outcome for children with advanced-stage rhabdomyosarcoma remains poor with contemporary treatment regimens. Evaluation of new drugs is important to improve clinical outcome. Because methotrexate has shown promising activity in the treatment of patients with recurrent rhabdomyosarcoma, we conducted a phase II trial in untreated children with advanced-stage disease to evaluate the efficacy and safety of this agent.

PATIENTS AND METHODS

Fifteen patients received 1 to 4 courses of high-dose methotrexate (HDMTX, 12 g/m2). Patients then received standard multiagent chemotherapy (vincristine, dactinomycin, cyclophosphamide, ifosfamide, mesna) with cytokine support and local radiotherapy. Patients who responded to HDMTX received four additional courses of this drug during continuation therapy.

RESULTS

Twelve patients were evaluable for response after 2 or more courses of HDMTX; 4 achieved a partial response (33.3%). After administration of standard chemotherapy and radiation, the estimated 2-year progression-free survival for all patients was 56% (SD 15%). The drug was well-tolerated and the most common side effects included mucositis, transient elevation of transaminases, and neutropenia. The four patients who received additional courses of HDMTX during continuation therapy had limited toxicity which included mucositis, anemia, and thrombocytopenia.

CONCLUSIONS

About one-third of children with previously untreated advanced-stage rhabdomyosarcoma responded to HDMTX. Its different mechanism of action and non-overlapping toxicity with other agents make HDMTX an attractive candidate for incorporation into front-line treatment regimens for rhabdomyosarcoma.

Hyperthermic isolated regional perfusion with cisplatin in the local treatment of spontaneous canine osteosarcoma: assessment of short-term effects

To increase the effect of cisplatin on locoregional osteosarcoma, the short-term effect of hyperthermic isolated regional perfusion (HIRP) with cisplatin (30 mg/L extremity volume) was studied in 28 dogs with spontaneous osteogenic sarcoma, using clinical, radiological, and histological parameters. Thirty days postoperatively, mortality was 14.3%. Total platinum levels at the start of perfusion were 28.2 +/- 14.3 mg/L. A significant improvement (P < 0.001) in clinical score was observed in the overall group at 6 and 12 weeks after perfusion. The radiological parameter showed a stationary X-ray 2 weeks after perfusion and an improved X-ray 6 weeks after perfusion. Overall histological scores showed a moderate effect according to the Huvos classification. No additional therapeutic effect, according to the three parameters, could be demonstrated by increasing the perfusate temperature by 1 degrees C. HIRP with cisplatin is feasible in the local treatment of spontaneous osteosarcoma in dogs with acceptable locoregional toxicity. However, the histological results were modest, with none of the dogs showing a complete response 6 weeks after perfusion. Therefore, the search for the ideal perfusion agent with substantial contribution to the limb-sparing treatment in human osteosarcoma continues.