Neoadjuvant chemotherapy for osteosarcoma of the extremity: intensification of preoperative treatment does not increase the rate of good histologic response to the primary tumor or improve the final outcome

Osteosarcoma in Adolescents and Young Adults

The epidemiology of osteosarcoma in adolescents and young adults (AYA) remains unclear. We aimed to assess and compare the clinical features of osteosarcoma between AYA and other age groups. We retrieved osteosarcoma cases diagnosed between 1999 and 2017 from the Korea Central Cancer Registry. We compared survival trends and clinical characteristics between AYA and other age groups. AYA comprised 43.3% (1309/3022) of the osteosarcoma cases. Compared to other age groups, the male-to-female ratio was highest in AYA (1.61:1). The proportion of tumors located in an extremity was 80.3% in AYA, which was lower than in young children (92.5%) or pubertal children (93.8%) but higher than in adults (55.7%) or the elderly (47.5%). As for treatments, 71.2% of AYA received local treatment and systemic chemotherapy, and 28.8% received only local treatment (surgery: 261, radiotherapy: 9, surgery and radiotherapy: 5). The 5-year overall survival (OS) was lower in AYA (68%) than in young children (78%) or pubertal children (73%) but higher than in adults (47%) or the elderly (25%). When AYA were divided into five subgroups by age, patients aged 15–19 years constituted the largest proportion (45.4%, n = 594). Additionally, the proportion of patients with a non-extremity tumor increased in an age-dependent manner, from 10.3% in AYA aged 15–19 years to 35.3% in AYA aged 35–39 years. OS did not significantly differ among the different age subgroups of AYA. The clinical characteristics and OS of the AYA were more similar to those of children than to those of adults. There is a need for cooperation between pediatric and adult oncologists for effective osteosarcoma treatment in AYA.

Derivation and validation of risk groups in patients with osteosarcoma utilizing regression tree analysis

BACKGROUND

For patients with osteosarcoma, apart from stage and primary site, we lack reliable prognostic factors for risk stratification at diagnosis. There is a need for further defined, discrete prognostic groups using presenting clinical features.

METHODS

We analyzed a cohort of 3069 patients less than 50 years of age, diagnosed with primary osteosarcoma of the bone between 1986 and 2013 from the Surveillance, Epidemiology, and End Results (SEER) database. Patients were randomly split into test and validation cohorts. Optimal cut points for age, tumor size, and grade were identified using classification and regression tree analysis. Manual recursive partitioning was used to identify discrete prognostic groups within the test cohort. These groups were applied to the validation cohort, and overall survival was analyzed using Cox models, Kaplan Meier methods, and log-rank tests.

RESULTS

After applying recursive partitioning to the test cohort, our initial model included six groups. Application of these groups to the validation cohort resulted in four final groups. Key risk factors included presence of metastases, tumor site, tumor grade, age, and tumor size. Patients with localized axial tumors were identified as having similar outcomes to patients with metastases. Age and tumor size were only prognostically important in patients with extremity tumors when assessed in the validation cohort.

CONCLUSIONS

This analysis supports prior reports that patients with axial tumors are a high-risk group, and demonstrates the importance of age and tumor size in patients with appendicular tumors. Biologic and genetic markers are needed to further define subgroups in osteosarcoma.

MTHFR variant is associated with high-dose methotrexate-induced toxicity in the Chinese osteosarcoma patients

Background

The role of Methylene tetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms in the efficacy and toxicity of MTX-based therapy remains uncertain. Our purpose was to clarify whether these two polymorphisms are associated with the outcome of chemotherapy in a cohort of Chinese osteosarcoma (OS) patients treated by high-dose MTX.

Methods

109 OS patients who had sequentially received high-dose MTX therapy were included in this study. Plasma MTX level was measured routinely at 0, 24, 48 and 72 h after the administration of MTX. Two variants of MTHFR were genotyped using TaqMan SNP Genotyping Assay, including rs1801133 (C667T) and rs1801131 (A1298C). The extent of toxicity induced by MTX, including hematological toxicity, hepatic toxicity, renal toxicity and mucositis, was scored from grade 1 to 4. Severe toxicity was defined as a grade score of ≥3. Patients were dichotomized as follows: grade <3 or ≥3 for toxicity, and ≤0.2 µmol/L or >0.2 µmol/L for plasma MTX level at 72 h. The frequencies of genotypes and allele were compared between the dichotomized groups with the Chi-square test.

Results

24.8% (27/109) of the patients were found to have significantly high plasma MTX level at the 72 h. Patients with high MTX level at 72 h were found to have significantly higher frequency of genotype TT of rs1801133 (p = 0.002). As for rs1801131, no significant association was found with plasma MTX level. Patients with severe hepatic toxicity or mucositis were found to have remarkably higher incidence of genotype TT of rs1801133 than those with mild toxicity (33.3% vs. 14.8%, p = 0.04 for hepatic toxicity; 34.8% vs. 19.8%, p = 0.05 for mucositis).

Conclusions

Variant rs1801133 was confirmed to have remarkable influence on the MTX-induced toxicity. We recommend identification of the genotype of MTHFR variant prior to the application of high-dose MTX to OS patients, which could be an important predictor to screen severe toxicities and thus improve treatment outcomes.

Does intensified chemotherapy increase survival outcomes of osteosarcoma patients? A meta-analysis

Study Design

Meta-analysis.

Background

Although some new insights have been offered for clinical and scientific relevance, minor progress has been made in osteosarcoma treatment after a dramatic survival improvement in the late 1980s with the addition of chemotherapy to surgery. Intensified chemotherapy strategies have been suggested to increase the survival rate of patients with osteosarcoma. We performed this study to access whether intensified chemotherapy strategiesincreased survival outcomes of osteosarcoma patients compared with conventional chemotherapy strategies.

Methods

MEDLINE/PubMed, EMBASE, BIOSIS Previews, and Cochrane Library were searched from database set up to October2016. Randomized controlled trials (RCTs) and comparative clinical trials (CCTs) on intensified versus conventional chemotherapy strategies for osteosarcoma patients met the inclusion criteria, and the methodological quality standard were retrieved and reviewed. Data on participant characteristics, interventions, follow-up period, and outcomes were extracted from the included studies and analyzed by Review Manager 5.3.

Results

12 studies (8 RCTs and 4CCT) involving 4112 patients were selected. There were no significant differences between intensified and conventional chemotherapy strategies group in 3-year event-free survival (OR, 1.01; 95% CI, [0.74–1.37]; P = 0.97), 5-year event-free survival (OR, 1.00; 95% CI, [0.86–1.17]; P = 0.97), and 5-year overall survival (OR, 1.04; 95% CI, [0.87–1.26]; P = 0.64), and good histologic response to preoperative chemotherapy (OR, 1.12; 95% CI, [0.78–1.60]; P = 0.55). Pooled analysis of local recurrence rate showed that local recurrence rate was significantly decreased in the intensified group compared with that in the conventional group (OR, 0.60; 95% CI, [0.42–0.85]; P = 0.004).

Conclusions

Intensified chemotherapy might not be a preferred treatment for all of the osteosarcoma patients.

Rho A Regulates Epidermal Growth Factor-Induced Human Osteosarcoma MG63 Cell Migration

Osteosarcoma, the most common primary bone tumor, occurs most frequently in children and adolescents and has a 5-year survival rate, which is unsatisfactory. As epidermal growth factor receptor (EGFR) positively correlates with TNM (tumor-node-metastasis) stage in osteosarcoma, EGFR may play an important role in its progression. The purpose of this study was to explore potential mechanisms underlying this correlation. We found that EGF promotes MG63 cell migration and invasion as well as stress fiber formation via Rho A activation and that these effects can be reversed by inhibiting Rho A expression. In addition, molecules downstream of Rho A, including ROCK1, LIMK2, and Cofilin, are activated by EGF in MG63 cells, leading to actin stress fiber formation and cell migration. Moreover, inhibition of ROCK1, LIMK2, or Cofilin in MG63 cells using known inhibitors or short hairpin RNA (shRNA) prevents actin stress fiber formation and cell migration. Thus, we conclude that Rho A/ROCK1/LIMK2/Cofilin signaling mediates actin microfilament formation in MG63 cells upon EGFR activation. This novel pathway provides a promising target for preventing osteosarcoma progression and for treating this cancer.

Variants of FasL and ABCC5 are predictive of outcome after chemotherapy-based treatment in osteosarcoma

Objectives

Previous pharmacogenetics studies showed that genetic variants could be indicative of the response to chemotherapy. We aimed to investigate whether variants of FasL, MSH2, ABCC5, CASP3 and CYP3A4 are associated with the outcome after chemotherapy-based treatment in osteosarcoma.

Methods

132 osteosarcoma patients who had completed the neoadjuvant chemotherapy in our center were included. 5-year progression-free survival (PFS) was assessed from the initial treatment to the earliest sign of disease progression or death from any cause. 5 SNPs were genotyped using TaqMan SNP Genotyping Assay, including rs763110 of FasL, rs4638843 of MSH2, rs939338 of ABCC5, rs2720376 of CASP3 and rs4646437 of CYP3A4. Patients were classified into two groups according to the 5-year PFS (event/no event). The chi-square test was used to analyze difference of genotype frequency. Logistic regression analysis was used to determine the independent predictors of the PFS rate.

Results

The overall 5-year PFS was 61.4% (81/132). Genotype TT/CT of rs763110 and genotype GG/AG of rs939338 were significantly associated with the event of 5-year PFS (p = 0.028 for rs763110; p = 0.039 for rs939338). Patients with no risk allele showed a 5-year PFS of 73.7% (42/57), which was significantly higher than a PFS of 54.2% (26/48) for patients with one risk allele and 48.1% (13/27) for patients with two different risk alleles (p = 0.03). Logistic regression analysis showed that allele T of FasL rs763110 and allele G of ABCC5 rs939338 were independent risk factors of the 5-year PFS. The ORs were 2.14 (95%CI = 1.13–3.35, p = 0.01) for rs763110 and 1.73 (95%CI = 1.05–2.52, p = 0.03) for rs939338, respectively.

Conclusions

The association of variants of FASL and ABCC5 with survival outcome after chemotherapy was validated in patients with osteosarcoma. Our findings may provide a new insight into a more personalized treatment for patients with osteosarcoma.

Targeting ABCB1 (MDR1) in multi-drug resistant osteosarcoma cells using the CRISPR-Cas9 system to reverse drug resistance

Background

Multi-drug resistance (MDR) remains a significant obstacle to successful chemotherapy treatment for osteosarcoma patients. One of the central causes of MDR is the overexpression of the membrane bound drug transporter protein P-glycoprotein (P-gp), which is the protein product of the MDR gene ABCB1. Though several methods have been reported to reverse MDR in vitro and in vivo when combined with anticancer drugs, they have yet to be proven useful in the clinical setting.

Results

The meta-analysis demonstrated that a high level of P-gp may predict poor survival in patients with osteosarcoma. The expression of P-gp can be efficiently blocked by the clustered regularly interspaced short palindromic repeats (CRISPR)-associated Cas9 system (CRISPR-Cas9). Inhibition of ABCB1 was associated with reversing drug resistance in osteosarcoma MDR cell lines (KHOSR2 and U-2OSR2) to doxorubicin.

Materials and Methods

We performed a meta-analysis to investigate the relationship between P-gp expression and survival in patients with osteosarcoma. Then we adopted the CRISPR-Cas9, a robust and highly efficient novel genome editing tool, to determine its effect on reversing drug resistance by targeting endogenous ABCB1 gene at the DNA level in osteosarcoma MDR cell lines.

Conclusion

These results suggest that the CRISPR-Cas9 system is a useful tool for the modification of ABCB1 gene, and may be useful in extending the long-term efficacy of chemotherapy by overcoming P-gp-mediated MDR in the clinical setting.

A phase II trial evaluating the feasibility of adding bevacizumab to standard osteosarcoma therapy

Increased vascular endothelial growth factor (VEGF) expression in osteosarcoma correlates with a poor outcome. We conducted a phase II trial to evaluate the feasibility and efficacy of combining bevacizumab, a monoclonal antibody against VEGF, with methotrexate, doxorubicin and cisplatin (MAP) in patients with localized osteosarcoma. Eligible patients received two courses of MAP chemotherapy before definitive surgery at week 10. Bevacizumab (15 mg/kg) was administered 3 days before starting chemotherapy then on day 1 of weeks 3 and 5 of chemotherapy. After surgery, patients received MAP for a total of 29 weeks; bevacizumab was added every 2 or 3 weeks on day 1 of chemotherapy at least 5 weeks after surgery. Group sequential monitoring rules were used to monitor for unacceptable bevacizumab-related targeted toxicity (grade 4 hypertension, proteinuria or bleeding, grade 3 or 4 thrombosis/embolism, and grade 2-4 major wound complications). Thirty-one patients (median age 12.8 years) with localized osteosarcoma were enrolled. No unacceptable targeted toxicities were observed except for wound complications (9 minor and 6 major), which occurred in 15 patients; none required removal of prosthetic hardware or amputation. The estimated 4-year event-free survival (EFS) rate and overall survival rate were 57.5 ± 10.0% and 83.4 ± 7.8%, respectively. Eight (28%) of 29 evaluable patients had good histologic response (<5% viable tumor) to preoperative chemotherapy. The addition of bevacizumab to MAP for localized osteosarcoma is feasible but frequent wound complications are encountered. The observed histologic response and EFS do not support further evaluation of bevacizumab in osteosarcoma.

ATIC Gene Polymorphism and Histologic Response to Chemotherapy in Pediatric Osteosarcoma

Accumulating evidence indicates that polymorphisms in folate pathway genes play a role in response to methotrexate (MTX) treatment in various diseases. This study explored the influence of these genetic polymorphisms on treatment outcome in pediatric osteosarcoma. Blood and tissue samples from 48 osteosarcoma patients were obtained, and the following polymorphisms were analyzed; SLC19A1 80G>A, DHFR 829C>T, MTHFR 677C>T, MTHFR 1298A>C, and ATIC 347C>G. We evaluated associations between these candidate gene polymorphisms and treatment outcome, including histologic response and event-free and overall survival, of patients treated with high-dose MTX. Patients with ATIC 347C>G exhibited a good histologic response to chemotherapy (odds ratio, 0.13; 95% confidence interval, 0.017-0.978; P=0.048). However, none of these single nucleotide polymorphisms we examined affected event-free survival or overall survival rates of the patients. Even though the role of single nucleotide polymorphisms of ATIC in chemotherapy-induced tumor necrosis has not been investigated yet, the ATIC 347C>G polymorphism may influence the levels of adenosine after MTX treatment, which may affect the histologic response of osteosarcoma. This relationship warrants validation in a larger, prospective cohort study.

Metformin displays in vitro and in vivo antitumor effect against osteosarcoma

Purpose

Patients with unresectable, relapsed, or refractory osteosarcoma need a novel therapeutic agent. Metformin is a biguanide derivative used in the treatment of type II diabetes, and is recently gaining attention in cancer research.

Methods

We evaluated the effect of metformin against human osteosarcoma. Four osteosarcoma cell lines (KHOS/NP, HOS, MG-63, U-2 OS) were treated with metformin and cell proliferation was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell cycle progression and apoptosis were evaluated using flow cytometric analysis, and migration and wound healing assay were performed. Fourteen female Balb/c-nude mice received KHOS/NP cell grafts in their thigh, and were allowed access to metformin containing water (2 mg/mL) ad libitum. Tumor volume was measured every 3–4 days for a period of 4 weeks.

Results

Metformin had a significant antiproliferative effect on human osteosarcoma cells. In particular, metformin inhibited the proliferation and migration of KHOS/NP cells by activation of AMP-activated protein kinase and consequent inhibition of the mammalian target of rapamycin pathway. It also inhibited the proliferation of cisplatin-resistant KHOS/NP clone cells. Analysis of KHOS/NP xenograft Balb/c-nude models indicated that metformin displayed potent in vivo antitumor effects.

Conclusion

Further studies are necessary to explore metformin's therapeutic potential and the possibilities for its use as an adjuvant agent for osteosarcoma.

Advances in emerging drugs for osteosarcoma

INTRODUCTION

Osteosarcoma (OS), the most common primary malignant bone tumor, is currently treated with pre- and postoperative chemotherapy in association with the surgical removal of the tumor. Conventional treatments allow to cure about 60 - 65% of patients with primary tumors and only 20 - 25% of patients with recurrent disease. New treatment approaches and drugs are therefore highly warranted to improve prognosis.

AREAS COVERED

This review focuses on the therapeutic approaches that are under development or clinical evaluation in OS. Information was obtained from different and continuously updated data bases, as well as from literature searches, in which particular relevance was given to reports and reviews on new targeted therapies under clinical investigation in high-grade OS.

EXPERT OPINION

OS is a heterogeneous tumor, with a great variability in treatment response between patients. It is therefore unlikely that a single therapeutic tool will be uniformly successful for all OS patients. This claims for the validation of new treatment approaches together with biologic/(pharmaco)genetic markers, which may select the most appropriate subgroup of patients for each treatment approach. Since some promising novel agents and treatment strategies are currently tested in Phase I/II/III clinical trials, we may hope that new therapies with superior efficacy and safety profiles will be identified in the next few years.

mTORC1 maintains the tumorigenicity of SSEA-4(+) high-grade osteosarcoma

Inactivation of p53 and/or Rb pathways restrains osteoblasts from cell-cycle exit and terminal differentiation, which underpins osteosarcoma formation coupled with dedifferentiation. Recently, the level of p-S6K was shown to independently predict the prognosis for osteosarcomas, while the reason behind this is not understood. Here we show that in certain high-grade osteosarcomas, immature SSEA-4⁺ tumor cells represent a subset of tumor-initiating cells (TICs) whose pool size is maintained by mTORC1 activity. mTORC1 supports not only SSEA-4⁺ cell self-renewal through S6K but also the regeneration of SSEA-4⁺ TICs by SSEA-4⁻ osteosarcoma cell dedifferentiation. Mechanistically, active mTORC1 is required to prevent a likely upregulation of the cell-cycle inhibitor p27 independently of p53 or Rb activation, which otherwise effectively drives the terminal differentiation of SSEA-4⁻ osteosarcoma cells at the expense of dedifferentiation. Thus, mTORC1 is shown to critically regulate the retention of tumorigenicity versus differentiation in discrete differentiation phases in SSEA-4⁺ TICs and their progeny.

Systematic review of high-dose and standard-dose chemotherapies in the treatment of primary well-differentiated osteosarcoma

The objective of this study is to evaluate whether high-dose chemotherapy is more efficacious than standard-dose chemotherapy in the treatment of primary well-differentiated osteosarcoma. The Cochrane systematic evaluation method was adopted. A database search was conducted in MEDLINE, Embase, OVID, the Cochrane Central Register of Controlled Trials database and the Chinese Biomedical Literature CD-ROM Database. The quality of the included studies was jointly evaluated by two reviewers, and homogeneous studies were included for meta-analysis. A total of five studies were included in this meta-analysis, with 1,415 subjects with primary, nonmetastatic, well-differentiated osteosarcoma in the limbs. No statistically significant differences were found between the high-dose chemotherapy group and the low-dose group in 5-year event-free survival [RR 1.04, 95 %CI (0.95, 1.13)], 5-year overall survival [RR 1.02, 95 %CI (0.95, 1.10)], local recurrence rate [RR 0.90, 95 %CI (0.59, 1.39)], proportion of subjects with good histological response [RR 0.93, 95 %CI (0.81, 1.07)], or limb salvage rate [RR 0.97, 95 %CI (0.92, 1.02)]. A statistically significant difference was observed in the 5-year event-free survival between the subjects with good histological response to preoperative chemotherapy and the subjects with poor histological response [RR 1.55, 95 %CI (1.19, 2.00), P < 0.001]. High-dose chemotherapy did not show superior efficacy to low-dose chemotherapy in the treatment of primary well-differentiated osteosarcoma. Further high-quality randomized controlled trials are needed to provide additional reliable evidence for our observation.

Knee reconstruction with endoprosthesis after extra-articular and intra-articular resection of osteosarcoma

OBJECTIVE

Extra-articular resection is necessary to obtain a wide margin for primary osteosarcomas invading the knee joint, and the limb is often reconstructed using a prosthesis. Here, outcomes of extra-articular and intra-articular procedures were compared.

METHODS

Between 1999 and 2012, 14 patients with osteosarcoma underwent extra-articular excision (n = 6; ages 23-65 years; mean follow-up 82.8 months) or intra-articular excision (n = 8; ages 8-58 years; mean follow-up 96.4 months). In the extra-articular group, there was one Enneking Stage IIA case and five Enneking Stage IIB cases. No local recurrences were noted in either group.

RESULTS

Patient outcomes were as follows (extra-articular cases vs. intra-articular cases): continuous disease-free (2 vs. 7), alive with disease (2 vs. 0) and death from disease (1 vs. 1). Average Musculoskeletal Tumor Society functional scores were 69.4% (range 63.3-83.3%) and 88.3% (range 70.0-96.7%) in the extra-articular and intra-articular groups, respectively, constituting a significant difference (P < 0.05). The 5-year oncological overall survival exceeded 80% in both groups. Amputation was necessary for one patient in the extra-articular group. The 5-year event-free prosthesis survival rates in the extra-articular and intra-articular groups were 33.3 and 75.0%, respectively (P < 0.05).

CONCLUSION

The extra-articular excision group developed more complications than the intra-articular excision group, as a result of extensive bone and muscle excision. The limb survival rates were similar in both groups. Our results suggest that extra-articular resection was a necessary and clinically acceptable procedure.

Targeting osteosarcoma vasculature with peptide obtained by phage display

Aim of the study

Tumour endothelial cells have been proven to have molecular markers distinct from normal endothelial cells. These specific molecular markers allow for targeting of the tumour vasculature with specific pharmacological vehicles to direct diagnostic or therapeutic modalities at the endothelial cells. By performing a phage display-based screening, this study aimed to identify a certain short peptide that could specifically bind to osteosarcoma vasculature.

Material and methods

We performed in vivo screening in the murine models of osteosarcoma with annular Ph.D.-C7C library in the present study. To explore the in vivo binding specificity of the retrieved peptide, we conjugated the peptide with fluorescein isothiocyanate (FITC) and injected it intravenously into osteosarcoma-bearing BALB-c mice.

Results

CTKPDKGYC was the dominant sequence isolated from in vivo screening and was named as NF-1. Fluorescence staining found that FITC-NF-1 peptide could be specifically homed to osteosarcoma vasculature while being almost undetectable in the heart, brain, lung and liver. Simultaneously, a small amount of fluorescence could also be detected in the renal glomerulus and renal tubule but not in renal vascular endothelium, indicating that FITC-NF-1 peptide might be excreted mainly through the renal-urinary route.

Conclusions

Our data suggest that, with high binding specificity to osteosarcoma vasculature, peptide NF-1 may have potential value in early diagnosis or targeted therapy for osteosarcoma.

Limb salvage surgery for osteosarcoma: Early results in Indian patients

BACKGROUND

While limb salvage surgery has long been established as the standard of care for osteosarcoma, large studies from Indian centers are few. Given the diverse socio economic milieu of our patients, it becomes significant to determine the feasibility and outcome of management of osteosarcoma in our population. We analyzed the early outcome of limb salvage surgery with multimodality treatment of osteosarcoma of the extremity/girdle bones at a tertiary North Indian Cancer Centre.

MATERIALS AND METHODS

A total of 51 limb salvage surgeries performed during the months between November 2008 and November 2012 were studied. Neoadjuvant/adjuvant chemotherapy was given by the pediatric/adult medical oncology teams as applicable. The mean followup was 19.45 months (range 2-50 months). The oncological outcome was correlated with age, sex, size of tumor, stage at presentation, site, histological subtype, type of chemotherapy protocol followed and necrosis seen on postoperative examination of resected specimen. The functional outcome of the patients was evaluated using the musculoskeletal tumor society (MSTS) scoring system.

RESULTS

Out of a total of 37 males and 14 females with an average age of 18.8 years, the 3 year overall survival was 66% and 3 year event free survival was 61.8%. In this group of patients with a short followup, a better oncological outcome was associated with good postoperative tumor necrosis, nonchondroblastic histology and age <14 years. The average MSTS score was highest in patients with proximal or distal femur prosthesis and the lowest in patients undergoing a knee arthrodesis.

CONCLUSION

The present study shows oncological and functional outcomes of limb salvage combined with chemotherapy in Indian patients with osteosarcoma comparable to those in world literature. Larger studies on Indian population with longer followup are recommended.

Neoadjuvant and adjuvant chemotherapy with high-dose ifosfamide, doxorubicin, cisplatin and high-dose methotrexate in non-metastatic osteosarcoma of the extremities: a phase II trial in Japan

From 1997 to 2003, 40 patients (all <40 years of age) with non-metastatic osteosarcoma of the extremities were treated with OOS-D and definitive surgery. Two cycles of doxorubicin 90 mg/m(2) plus cisplatin 120 mg/m(2) and ifosfamide 15 g/m(2) were given as neoadjuvant chemotherapy, and two cycles of doxorubicin/cisplatin and ifosfamide, and two cycles of high-dose methotrexate (10-12 g/m(2)) were given post-operatively. All patients underwent limb salvage surgeries, and 66% showed good response to neoadjuvant chemotherapy. With a median follow-up period of 117 months, 31 of the evaluable 40 patients were continuously disease-free, 7 were currently alive with no evidence of disease, and 2 died of disease. There was no local recurrence. The 5-year event-free and overall survival rates were 83 and 98%, respectively. The 10-year event-free and overall survival rates were 80 and 95%, respectively. The major form of toxicity was haematological one.

Synergistic apoptotic effect of crocin and cisplatin on osteosarcoma cells via caspase induced apoptosis

Crocin is well-known traditional Chinese medicine which is extracted from saffron. However, its role in osteosarcoma has not been well understood. Therefore, we used crocin and cisplatin individually or jointly on MG63 and OS732 cells so as to explore whether crocin could induce cellular apoptosis and suppress the ability of invasion of osteosarcoma cells. Cell survival rates, changes of cellular shape, cell apoptosis and cell invasion were analyzed, respectively, by 3-(4,5)-dimethylthiahiazo (-z-y1)-2,5-di- phenytetrazoliumromide (MTT) assay, inverted phase contrast microscope and fluorescence microscope, flow cytometry, and Transwell invasion chamber methods. The expressions of caspase-3 and caspase-8 were detected by Western blot. The survival rate of combined application was significantly lower than that of the individual application. Apoptosis-inducing effect of combined application was much stronger than that of individual application. The invasion ability of MG63 and OS732 cells was restrained significantly in the combined group compared with the individual group and control group. Combined group has the effect of up-regulating the expressions of cleaved-caspase-3 and caspase-8. The results suggested that combination of crocin and cisplatin has a strong killing effect on osteosarcoma cells and suppresses the ability of invasion of MG63 and OS732 cells which might be related to up-regulate the expression of caspase-3 and caspase-8.

Survival trends and long-term toxicity in pediatric patients with osteosarcoma

Background. This study was conducted to investigate the clinical characteristics and treatment results of osteosarcoma in pediatric patients during the past 30 years. Trends in survival rates and long-term toxicity were analyzed. Procedure. 130 pediatric patients under the age of 20 years with primary localized or metastatic high-grade osteosarcoma were analyzed regarding demographic, treatment-related variables, long-term toxicity, and survival data. Results. Comparison of the different time periods of treatment showed that the 5-year OS improved from 58.6% for children diagnosed during 1979–1983 to 78.6% for those diagnosed during 2003–2008 (P = 0.13). Interestingly, the basic treatment agents including cisplatin, doxorubicin, and methotrexate remained the same. Treatment reduction due to acute toxicity was less frequent in patients treated in the last era (7.1% versus 24.1% in patients treated in 1979–1983; P = 0.04). Furthermore, late cardiac effects and secondary malignancies can become evident many years after treatment. Conclusion. We elucidate the prevalence of toxicity to therapy of patients with osteosarcoma over the past 30 years. The overall improvement in survival may in part be attributed to improved supportive care allowing regimens to be administered to best advantage with higher tolerance of chemotherapy and therefore less chemotherapy-related toxicity.

Epidermal growth factor receptor: is it a feasible target for the treatment of osteosarcoma?

Purpose

Features of epidermal growth factor receptor (EGFR) expression in osteosarcoma and in vitro efficacies of EGFR inhibitors against osteosarcoma cells were evaluated.

Materials and Methods

Thirty biopsy samples of osteosarcoma patients were retrospectively analyzed for EGFR protein expression by immunohistochemistry. Relationships between EGFR expression and clinicopathologic characteristics and treatment outcomes were evaluated. Four osteosarcoma cell lines were analyzed for EGFR and p-EGFR expression by western blotting. Efficacies of gefitinib and BIBW2992 on osteosarcoma cells were evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Tyrosine kinase domains in exons 18 to 21 were sequenced and gene expression analyses of EGFR and PTEN were performed in four osteosarcoma cell lines.

Results

EGFR protein was expressed in 27 (90%) samples (6 low, 12 intermediate, 9 high) and in three cell lines. Intermediate or high staining for EGFR was related to a tumor volume<150 mL (p<0.001) and histologic subtype other than osteoblastic type (p=0.03). However, EGFR expression was not associated with histologic response to preoperative chemotherapy or survival. Gefitinib and BIBW 2992 did not have any significant inhibitory effect on cell viabilities. DNA sequencing analysis revealed three osteosarcoma cell lines have single base changes at codon 2361 of exon 20 (G to A), without affecting translation results. Furthermore, no mutation was found to be associated with constitutive EGFR activation.

Conclusion

In the present study, gefitinib and BIBW2992 were not effective against osteosarcoma cells. However, as osteosarcoma cells express EGFR, further studies are necessary to explore the potential of other therapeutic agents targeting EGFR.

New targets and approaches in osteosarcoma

Osteosarcoma is the most common primary tumor of bone. Approximately 2/3 of patients who present with localized osteosarcoma can be expected to be cured of their disease with surgery and routine chemotherapy. Only 1/3 of patients with metastases detectable at presentation will be cured. These survival trends have stagnated over the past 20 years using conventional chemotherapy. New agents need to be rationally investigated to strive for improvement in the survival of patients diagnosed with osteosarcoma. This manuscript will review the rationale for conventional chemotherapy used in the treatment of osteosarcoma, as well as agents in varying stages of development that may have promise for treatment in the future.

MDM2 inhibitor Nutlin-3a suppresses proliferation and promotes apoptosis in osteosarcoma cells

Restoring p53 activity by inhibiting the interaction between p53 and the mouse double minutes clone 2 (MDM2) offers an attractive approach to cancer therapy. Nutlin-3a is a small-molecule inhibitor that inhibits MDM2 binding to p53 and subsequent p53-dependent DNA damage signaling. In this study, we determined the efficacy of Nutlin-3a in inducing p53-mediated cell death in osteosarcoma (OS) cell lines both in vivo and in vitro. Targeted disruption of the p53-MDM2 interaction by Nutlin-3a stabilizes p53 and selectively activates the p53 pathway only in OS cells with wild-type p53, resulting in a pronounced anti-proliferative and cytotoxic effect due to G1 cell cycle arrest and apoptosis both in vitro and in vivo. p53 dependence of these alternative outcomes of Nutlin-3a treatment was shown by the abrogation of these effects when p53 was knocked-down by small interfering RNA. These data suggest that the disruption of p53-MDM2 interaction by Nutlin-3a might be beneficial for OS patients with MDM2 amplification and wt p53 status.

RANKL expression is related to treatment outcome of patients with localized, high-grade osteosarcoma

BACKGROUND

The receptor activator of nuclear factor κB ligand (RANKL/TNFSF11) is expressed in metastatic bone cancer cells and has been suggested to play a key role in cell migration and metastatic behavior. We determined whether RANKL expression is correlated to clinical behavior of localized, high-grade osteosarcoma.

PATIENTS AND METHODS

This retrospective, immunohistochemical study was performed using materials obtained from 40 patients treated at Korea Cancer Center Hospital between 1995 and 2007. Prechemotherapy biopsy samples were stained for RANKL and correlations between RANKL expression and clinical characteristics and outcomes were evaluated. Staining was interpreted in a semiquantitative manner using an intensity based scoring system.

RESULTS

Thirty cases (75.0%) stained positively for RANKL; 15 (50.0%) had a high RANKL score (≥ 4) and the other 15 a low RANKL score (≤3). RANKL expression and RANKL scores were not related to age, sex, tumor location, tumor volume, or pathologic subtype. However, RANKL expression was related to a poor response to preoperative chemotherapy (P = 0.03) and a high RANKL score was associated with inferior survival. The 5-year event-free survival of patients with RANKL score ≥4 was 17.8 ± 10.5%, which was far worse than those with RANKL scores 1-3 or 0 (50.0 ± 15.8%, 56.0 ± 13.7%, respectively, P = 0.02).

CONCLUSIONS

The RANKL-RANK-OPG axis might be a promising target for the treatment of osteosarcoma, but further studies are needed to verify our data in a larger cohort.

Prognostic significance of early lymphocyte recovery in pediatric osteosarcoma

BACKGROUND

Evidence suggests early lymphocyte recovery after chemotherapy predicts superior outcome for patients with cancer, a phenomenon not previously investigated in osteosarcoma. This study determined the prognostic significance of early lymphocyte recovery for pediatric patients with osteosarcoma.

PROCEDURES

We reviewed data of 19 consecutive patients treated for osteosarcoma at our institution from 1997 to 2007. After initial chemotherapy, patients were separated into two groups: early versus late lymphocyte recovery, using a threshold absolute lymphocyte count of ≥ 800 cells/µl on day 14 (ALC-14).

RESULTS

The 5-year overall survival (OS) for our cohort was 73.7% [± 10.1 standard error (SE)]. Thirteen patients (68%) had an ALC-14 ≥ 800 cells/µl, with 12/13 alive and 5-year OS of 92.3% (± 7.4 SE). In contrast, six patients (32%) had an ALC-14 < 800 cells/µL, with 1/6 alive and 5-year OS of 33.3% (± 19.2 SE). The difference is statistically significant (P = 0.0013, log-rank test). Two patients presented with multifocal disease at diagnosis, had late lymphocyte recovery and died. One patient presented with metastatic disease, had early lymphocyte recovery and is alive. Six patients developed relapsed disease with a 5-year OS of 33.3% (± 19.2 SE). The majority (5/6) of patients with relapsed disease died while on active therapy. The only survivor in this group had an ALC-14 > 800 cells/µl and recently completed relapse therapy.

CONCLUSIONS

These data demonstrate that early lymphocyte recovery represents a significant prognostic indicator for osteosarcoma. Early identification and risk stratification therapy based on the ALC-14 threshold may improve outcomes and our knowledge of this disease.

Inhibition of tumors cell growth in osteosarcoma-bearing SD rats through a combination of conventional and metronomic scheduling of neoadjuvant chemotherapy

AIM

To investigate whether a combination of conventional and metronomic scheduling of chemotherapy could enhance and extend the effectiveness of chemotherapy against osteosarcoma.

METHODS

A total of 110 osteosarcoma-bearing SD rats were randomly divided into four groups, three of which were given conventional, metronomic or combination scheduling of chemotherapy, and the remaining one served as a control. Tumor volumes were measured every week during the treatment period of 8 weeks. At the end of treatment, tumors were removed from the rats and weighed. Expression of VEGFA in tumors was determined using Western blot assays.

RESULTS

As indicated by the tumor volume, conventional and metronomic schedules showed similar trends in tumor growth curves, and both of them lost their inhibitory effect in the sixth week, whereas the combination schedule maintained effectiveness until the end of treatment. Statistical significance with tumor volumes and weights was found among the groups (P<0.001), with combination scheduling being the most effective (P<0.001). Western blot indicated that all the therapy groups had significantly decreased expression of VEGFA (P<0.01), and the combination scheduling group had the lowest VEGFA expression.

CONCLUSION

Combination of conventional and metronomic scheduling of chemotherapy could be a promising treatment for osteosarcoma. Antiangiogenesis contributed to the effect of combination scheduling.

Prognostic markers in osteosarcoma

Osteosarcoma is the most common bone tumor seen in the pediatric and adolescent age group. Survival rates in osteosarcoma have improved considerably from 20 to 65% since the 1980s with the advent of multiagent chemotherapy. Further improvement in survival has not been achieved owing to lack of well-validated prognostic markers and better therapeutic agents. Markers involved with angiogenesis, cell adhesion, apoptosis and cell cycle have been shown recently to play an important role in osteosarcoma growth, differentiation and metastasis. Over the coming years, the new molecular markers may be able not only to prognosticate osteosarcoma patients at baseline but also to serve as therapeutic targets and thereby improve survival rates further. Noninvasive imaging methods in osteosarcoma such as PET-CT and dynamic contrast enhanced and diffusion-weighted MRI hold a lot of promise as surrogate methods for prognostication and response assessment.

Microarray analysis identifies distinct gene expression profiles associated with histological subtype in human osteosarcoma

Osteosarcoma is the most common primary malignant bone tumour. Currently osteosarcoma classification is based on histological appearance. It was the aim of this study to use a more systematic approach to osteosarcoma classification based on gene expression analysis and to identify subtype specific differentially expressed genes. We analysed the global gene expression profiles of ten osteosarcoma samples using Affymetrix U133A arrays (five osteoblastic and five non-osteoblastic osteosarcoma patients). Differential gene expression analysis yielded 75 genes up-regulated and 97 genes down-regulated in osteoblastic versus non-osteoblastic osteosarcoma samples, respectively. These included genes involved in cell growth, chemotherapy resistance, angiogenesis, steroid- and neuropeptide hormone receptor activity, acute-phase response and serotonin receptor activity and members of the Wnt/ß-catenin pathway and many others. Furthermore, we validated the highly differential expression of six genes including angiopoietin 1, IGFBP3, ferredoxin 1, BMP, decorin, and fibulin 1 in osteoblastic osteosarcoma relative to non-osteoblastic osteosarcoma. Our results show the utility of gene expression analysis to study osteosarcoma subtypes, and we identified several genes that may play a role as potential therapeutic targets in the future.

Relative tumor burden predicts metastasis-free survival in pediatric osteosarcoma

BACKGROUND

To analyze the significance of relative tumor burden in pediatric osteosarcoma.

METHODS

We retrospectively reviewed 241 patients with localized pediatric osteosarcoma and measured tumor size on MR images at presentation. Absolute tumor size parameters measured on MR images were converted to relative values by dividing body surface area. Both absolute and relative size parameters were analyzed for their correlation with metastasis-free survival (MFS).

RESULTS

The 5-year MFS was 67.5 +/- 3.1%, with median follow-up of 72 months (range, 8-205 months). In addition to poor histologic response (RR 3.24; 95% CI: 1.99-5.28; P < 0.001), large relative tumor plane (RTP; RR 3.28; 95% CI: 1.72-6.25; P < 0.001), large relative tumor area (RTA; RR 4.14; 95% CI: 1.53-11.22; P = 0.005), and large absolute tumor width (ATW; RR; 3.10; 95% CI: 1.23-7.79; P = 0.02) shortened the MFS. When survival was analyzed by combining RTP and histologic response, patients with small RTP and a good response showed the best survival (5-year MFS of 90.2 +/- 3.6%), while those with large RTP and a poor response showed the worst survival (5-year MFS of 45.1 +/- 6.6%).

CONCLUSION

Relative two-dimensional tumor size parameters (RTP and RTA) rather than absolute values are useful prognostic factors in pediatric osteosarcoma patients.

Functional imaging of multidrug resistance in an orthotopic model of osteosarcoma using 99mTc-sestamibi

PURPOSE

The purpose of this work was the development of an orthotopic model of osteosarcoma based on luciferase-expressing tumour cells for the in vivo imaging of multidrug resistance (MDR) with (99m)Tc-sestamibi.

METHODS

Doxorubicin-sensitive (143B-luc(+)) and resistant (MNNG/HOS-luc(+)) osteosarcoma cell lines expressing different levels of P-glycoprotein and carrying a luciferase reporter gene were inoculated into the tibia of nude mice. Local tumour growth was monitored weekly by bioluminescence imaging and X-ray. After tumour growth, a (99m)Tc-sestamibi dynamic study was performed. A subset of animals was pre-treated with an MDR inhibitor (PSC833). Images were analysed for calculation of (99m)Tc-sestamibi washout half-life (t (1/2)), percentage washout rate (%WR) and tumour/non-tumour (T/NT) ratio.

RESULTS

A progressively increasing bioluminescent signal was detected in the proximal tibia after 2 weeks. The t (1/2) of (99m)Tc-sestamibi was significantly shorter (p < 0.05) in drug-resistant MNNG/HOS-luc(+) tumours (t (1/2) = 87.3 +/- 15.7 min) than in drug-sensitive 143B-luc(+) tumours (t (1/2) = 161.0 +/- 47.4 min) and decreased significantly with PSC833 (t (1/2) = 173.0 +/- 24.5 min, p < 0.05). No significant effects of PSC833 were observed in 143B-luc(+) tumours. The T/NT ratio was significantly lower (p < 0.05) in MNNG/HOS-luc(+) tumours than in 143B-luc(+) tumours at early (1.55 +/- 0.22 vs 2.14 +/- 0.36) and delayed times (1.12 +/- 0.11 vs 1.62 +/- 0.33). PSC833 had no significant effects on the T/NT ratios of either tumour.

CONCLUSION

The orthotopic injection of tumour cells provides an animal model suitable for functional imaging of MDR. In vivo bioluminescence imaging allows the non-invasive monitoring of tumour growth. The kinetic analysis of (99m)Tc-sestamibi washout provides information on the functional activity of MDR related to P-glycoprotein expression and its pharmacological inhibition in osteosarcoma.

Syndecan-2 Affects the Basal and Chemotherapy-Induced Apoptosis in Osteosarcoma

Syndecans are transmembrane heparan sulfate proteoglycans controlling cell adhesion, migration, and proliferation. We previously showed that syndecan-2 is involved in the control of apoptosis in cultured osteosarcoma cells. These data led us to the hypothesis that syndecan-2 may play a role in the apoptotic signaling in bone tumors. We immunohistochemically analyzed tissue sections from biopsies from 21 patients with well-characterized osteosarcoma. These tissues expressed low levels of syndecan-2 compared with osteoblasts and osteocytes in normal bone. Cultured human osteosarcoma cells also produced lower mRNA levels of syndecan-2 than normal osteoblastic cells. Moreover, the presence of syndecan-2 correlated with spontaneous apoptosis in osteosarcoma tissues as assessed by detection of DNA fragmentation in situ. Overexpression of syndecan-2 resulted in decreased number of migrating and invading U2OS osteosarcoma cells in Matrigel. In addition, overexpression of syndecan-2 sensitized human osteosarcoma cells to chemotherapy-induced apoptosis, increasing the response to methotrexate, doxorubicin, and cisplatin. Consistently, knockdown of the proteoglycan using stable transfection with a plasmid coding small interfering RNA resulted in inhibition of chemotherapy-induced apoptosis. Analysis of syndecan-2 expression both in biopsies and in corresponding postchemotherapy-resected tumors, as well as in cells treated with methotrexate or doxorubicin, showed that the cytotoxic action of chemotherapy can be associated with an increase in syndecan-2. These results provide support for a tumor-suppressor function for syndecan-2 and suggest that dysregulation of apoptosis may be related to abnormal syndecan-2 expression or induction in osteosarcoma. Moreover, our data identify syndecan-2 as a new factor mediating the antioncogenic effect of chemotherapeutic drugs.

SFOP OS94: a randomised trial comparing preoperative high-dose methotrexate plus doxorubicin to high-dose methotrexate plus etoposide and ifosfamide in osteosarcoma patients

The SFOP-OS94 randomised multi-centre trial was designed to determine whether preoperative chemotherapy regimen combining high-dose methotrexate courses and etoposide-ifosfamide could improve the proportion of good histologic response (5% viable cells) compared to a regimen based on high-dose methotrexate and doxorubicin, in children/adolescents with localised high-grade limb osteosarcoma. Postoperative chemotherapy was adapted to the histologic response. Overall, 234 patients were randomised between 1994 and 2001. There were 56% good responders in the etoposide-ifosfamide arm versus 39% in the doxorubicin arm (p-value=0.009). With a median follow-up of 77 months, the 5-year event-free survival of the entire population was 62%, slightly greater in the etoposide-ifosfamide arm than in the doxorubicin arm, but the difference was not significant (Hazard Ratio: HR=0.71, 95%CI: 0.5-1.06, p-value=0.09). Five-year overall survival of the entire population was 76%, similar in both arms (HR=0.95, 95%CI: 0.6-1.6, p-value=0.85). Toxicity was manageable with different acute toxicity profiles between treatment arms. No acute toxicity related death was reported. About 43% of the patients in the etoposide-ifosfamide arm were event-free at 3 years without having received any doxorubicin or cisplatin, thus avoiding the risk of long-term cardio- and ototoxicity.

Multidrug resistance mediated by ABC transporters in osteosarcoma cell lines: mRNA analysis and functional radiotracer studies

Drug resistance remains a significant impediment to successful chemotherapy and constitutes a major prognostic factor in osteosarcoma (OS) patients. This study was designed to identify the role and prognostic significance of multidrug-resistance (MDR)-related transporters, such as multidrug resistance protein 1 (MDR1), multidrug-resistance-associated protein (MRP1) and breast-cancer-related protein (BCRP), in OS using cationic lipophilic radiotracers. We evaluated the chemosensitivity of four OS cell lines (Saos-2, 143B, MNNG/HOS and U-2OS) to doxorubicin (DOX), cisplatin (CIS) and methotrexate. The expression of MDR-related transporters was analyzed at mRNA level by quantitative polymerase chain reaction and at functional level by 99mTc sestamibi and 99mTc tetrofosmin. The effectiveness of MDR modulators [cyclosporin A (CsA) and imatinib] on transporter inhibition and on the reversal of resistance was also assessed. MNNG/HOS and U-2OS cells expressing high levels of MDR1 were highly resistant to DOX and showed reduced accumulation and higher efflux for radiotracers. Although MRP1 was uniformly expressed in all cells, only U-2OS was resistant to CIS. CsA restored sensitivity to DOX and CIS, and enhanced the accumulation and efflux half-life of radiotracers in MDR1-expressing cell lines. The chemosensitivity of OS cells to DOX was strongly dependent on mRNA MDR1 expression and could be circumvented by adding CsA. The kinetic parameters of radiotracers correlated with MDR1 expression levels, hence predicting DOX resistance. We concluded that sensitivity to chemotherapy is strongly dependent on the expression of MDR1 transporter and that radiotracer studies could prove clinically useful in predicting chemotherapy response and in evaluating the efficacy of MDR-reversing agents.

Bone metastases in osteosarcoma patients treated with neoadjuvant or adjuvant chemotherapy: the Rizzoli experience in 52 patients

INTRODUCTION

There have been no large-scale studies reporting the outcome of patients with osteosarcoma who first relapse with bone metastases, but there have been several case reports describing a much poorer prognosis for these patients than for those who relapse with lung metastases.

METHODS

We compared 52 patients with skeletal metastases as first relapse after neoadjuvant or adjuvant treatment for osteosarcoma of the extremity given at our institution between 1972 and 1999 with 371 contemporary patients treated with the same chemotherapy protocols, who first relapsed with lung metastases.

RESULTS

We found that the 52 patients with bone metastases had a higher rate of local recurrences (36% vs. 6%), a lower rate of remission (35% vs. 77%), and lower rates of 5-year event-free survival (11% vs. 27%) and overall survival (13% vs. 31%) (p < 0.01 for all comparisons).

INTERPRETATION

The prognosis of patients who relapse with bone metastases--unless they have a single late-appearing metastasis--is worse than the prognosis of patients who first relapse with lung metastases. There was no difference in outcome between patients with single, resectable and late-appearing skeletal metastases and patients relapsing in the lung.

Outcome of postradiation osteosarcoma does not correlate with chemotherapy response

Postradiation osteosarcoma is a rare tumor with a historically poor prognosis. Recent reports concerning the prognosis of the disease have been conflicting. We ascertained the long-term outcome of patients with this disease treated in the era of contemporary chemotherapy. Twenty-seven patients diagnosed with postradiation osteosarcoma and treated with chemotherapy and surgical resection from 1980-2003 were identified. Demographics, anatomic location, stage, chemo- therapy, necrosis rate, recurrence and metastatic rates were recorded; Kaplan-Meier survival rates were estimated. The median age was 54 years (range, 12-86 years). Nineteen patients were female and eight patients were male. Median followup was 39.2 months (range, 0-218 months). Twenty-two patients received induction chemotherapy for a mean of four cycles (range, 2-6 cycles). Mean tumor necrosis was 63.5%. Seven patients had 90% necrosis; four of these patients died of their disease. The mean survival was 23 months, and the 5-year disease free survival estimate was 27.2%. Histologic response to chemotherapy did not correlate with survival. Patients who had a latency of greater than 10 years after radiation had a better prognosis. Unlike conventional osteosarcoma, response to chemotherapy (necrosis) did not have prognostic significance. Current chemotherapy regimens fail to impact survival in postradiation osteosarcoma.

LEVEL OF EVIDENCE

Therapeutic study, level IV (retrospective comparative study).

Adenovirus-mediated p53 tumor suppressor gene therapy of osteosarcoma

The clinical outcome for osteosarcoma (OS) remains discouraging despite efforts to optimize treatment using conventional modalities including surgery, radiotherapy and chemotherapy. Novel therapeutic approaches based on our expanding understanding of the mechanisms of tumor cell killing have the potential to alter this situation. Tumor suppressor gene therapy aims to restore the function of a tumor suppressor gene lost or functionally inactivated in cancer cells. One such molecule, the p53 tumor suppressor gene plays a critical role in safeguarding the integrity of the genome and preventing tumorigenesis. Introduction of wild-type (wt) p53 into transformed cells has been shown to be lethal for most cancer cells in vitro, but clinical trials of p53 gene replacement have had limited success. Analysis of these clinical trials highlighted the insufficient efficacy of current vectors and low proapoptotic activity of wt p53 as a single agent in vivo. In this review, a contemporary summarization of the current status of adenovirus-mediated p53 gene therapy of OS is presented. Advancement in our understanding of p53 tumor suppressor activity, the molecular biology of chemoresistant OS, and recent advances in tumor targeting with adenoviral vectors are also addressed. Based on these parameters, prospects for future investigations are proposed.

Dose intensity of chemotherapy for osteosarcoma and outcome in the Cooperative Osteosarcoma Study Group (COSS) trials

BACKGROUND

The prognostic relevance of dose intensity in the treatment of osteosarcoma is still under discussion. The aim of this study was to investigate whether higher dose intensities of chemotherapy correlated with better outcomes.

PROCEDURE

This study contains 917 consecutive Cooperative Osteosarcoma Study Group (COSS) patients <40 years with primary, high-grade central, nonmetastatic osteosarcoma of the extremities, who were in complete remission at least until day 200 after the start of chemotherapy. All COSS-protocols were based on a uniform treatment concept of aggressive polychemotherapy and definitive surgery. Chemotherapy dose intensity in the first 200 days of treatment (DI200) and possible correlations to overall and event-free survival were investigated. The study focused on methotrexate, doxorubicin, cisplatin, and ifosfamide, which are considered to be the most active drugs against osteosarcoma. Multivariate analyses including well-known prognostic factors were added to complete this investigation.

RESULTS

Until day 200, patients received 80.7 +/- 26.1 g/m2 methotrexate (MTX); 242 +/- 69 mg/m2 doxorubicin (DOX); 324 +/- 133 mg/m2 cisplatin (DDP); and 13.9 +/- 9.8 g/m2 ifosfamide (IFO) (mean +/- SD). Median follow-up from day 200 was 6.6 (0.02-22.1) years. There was no correlation between a higher DI200 of any one drug and better outcomes in uni- or multi-variate analyses. Total treatment intensity did not show such correlations either.

CONCLUSIONS

In an overall setting of intensive multidrug treatment of osteosarcoma, we could not prove that higher dose intensities correlate with better outcomes.

Gemcitabine radiosensitization after high-dose samarium for osteoblastic osteosarcoma

Osteoblastic metastases and osteosarcoma can avidly concentrate bone-seeking radiopharmaceuticals. We sought to increase effectiveness of high-dose (153)Samarium ethylenediaminetetramethylenephosphonate (153Sm-EDTMP, Quadramet) on osteosarcomas using a radiosensitizer, gemcitabine. Fourteen patients with osteoblastic lesions were treated with 30 mCi/kg 153Sm-EDTMP. Gemcitabine was administered 1 day after samarium infusion. Residual total body radioactivity was within the safe range of <3.6 mCi on day +14 (1.1 +/- 0.4 mCi; range, 0.67-1.8 mCi). All patients received autologous stem cell reinfusion 2 weeks after 153Sm to correct expected grade 4 hematopoietic toxicity. Peripheral blood progenitor cells were infused in 11 patients; three patients had marrow infused. Blood count recovery was uneventful after peripheral blood progenitor cells in 11 of 11 patients. Toxicity from a single infusion of gemcitabine (1,500 mg/m2) in combination with 153Sm-EDTMP was minimal (pancytopenia). However, toxicity from a daily gemcitabine regimen (250 mg/m2/d x 4-5 days) was excessive (grade 3 mucositis) in one of two patients. There were no reported episodes of hemorrhagic cystitis (hematuria) or nephrotoxicity. At the 6- to 8-week follow-up, there were six partial remissions, two mixed responses, and six patients with progressive disease. In the 12 patients followed >1 year, there have been no durable responses. Thus, although high-dose 153Sm-EDTMP + gemcitabine has moderate palliative activity (improved pain; radiologic responses) in this poor-risk population, additional measures of local and systemic control are required for durable control of relapsed osteosarcoma with osteoblastic lesions. The strategy of radioactive drug binding to a target followed by a radiosensitizer may provide synergy and improved response rate.

The feasibility of neoadjuvant high-dose chemotherapy and autologous peripheral blood stem cell transplantation in patients with nonmetastatic high grade localized osteosarcoma: results of a phase II study

BACKGROUND

The primary and secondary objectives of the current study were to improve the > or = 90% tumor necrosis rate and assess the toxicity profile of the neoadjuvant high-dose chemotherapy (HDC) regimen, respectively.

METHODS

Twenty-two patients with AJCC Stage IIB high-grade osteosarcoma were included in the current study. Two cycles of an induction chemotherapy regimen including cisplatin, doxorubicin, and ifosfamide followed by HDC and autologous peripheral blood stem cell support or transplantation (APBSCT) were given. After engraftment was achieved, the patients underwent limb-sparing surgery (LSS) followed by three to six cycles of postoperative chemotherapy depending on the tumor necrosis rate.

RESULTS

The median follow-up, the total duration of treatment, and the time to surgery were 23.7 months, 5.96 months, and 3.03 months, respectively. The necrosis rate was at least 90% in 82% of the cases. The 3-year overall survival (OS) and disease-free survival (DFS) rates were 83% and 70%, respectively. Leukopenia, anemia, thrombocytopenia, nausea and emesis, and mucositis were the most frequent Grade 3 and Grade 4 toxicities (according to the National Cancer Institute Common Toxicity Criteria [version 2.0]) of induction, high-dose, and adjuvant chemotherapies. At the time of last follow-up, no patient had died of chemotherapeutic toxicity. LSS was performed in all patients. Surgery-related complications were reported in 3 of 22 patients. Functional scoring results were excellent in eight patients, good in nine patients, fair in two patients, and poor in three patients.

CONCLUSIONS

The results of the current Phase II study suggest that neoadjuvant HDC provides a greater than 90% necrosis rate with acceptable toxicity. A short duration of therapy and the feasibility of LSS in all patients are additional advantages of this approach.

Pediatric osteosarcoma: a 35-year experience in Slovenia

The purpose of this study was to review all the children and adolescents treated for osteosarcoma in Slovenia between 1968 and 1997. Seventy-four patients were included in this retrospective study and classified according to the newly devised classification based on clinical and imaging studies. The overall survival rate is 48%. The stage of the disease and the treatment, including chemotherapy, are the only prognostic factors significantly influencing survival. The survival of patients with osteosarcoma has improved with chemotherapy, but new therapeutic strategies should be found for different stages of disease. The authors' newly devised classification based on clinical and imaging studies proved to be adequate.

An expression signature classifies chemotherapy-resistant pediatric osteosarcoma

Osteosarcoma is the most common malignant bone tumor in children. Osteosarcoma patients who respond poorly to chemotherapy are at a higher risk of relapse and adverse outcome. Therefore, it was the aim of this study to identify prognostic factors at the time of diagnosis to characterize the genes predictive of poor survival outcome and to identify potential novel therapeutic targets. Expression profiling of 30 osteosarcoma diagnostic biopsy samples, 15 with inferior necrosis following induction chemotherapy (Huvos I/II) and 15 with superior necrosis following induction chemotherapy (Huvos III/IV), was conducted using Affymetrix U95Av2 oligonucleotide microarrays. One hundred and four genes were found to be statistically significant and highly differentially expressed between Huvos I/II and III/IV patients. Statistically significant genes were validated on a small independent cohort comprised of osteosarcoma xenograft tumor samples. Markers of Huvos I/II response predominantly were gene products involved in extracellular matrix (ECM) microenvironment remodeling and osteoclast differentiation. A striking finding was the significant decrease in osteoprotegerin, an osteoclastogenesis inhibitory factor. Additional genes involved in osteoclastogenesis and bone resorption, which were statistically different, include annexin 2, SMAD, PLA2G2A, and TGFbeta1. ECM remodeling genes include desmoplakin, SPARCL1, biglycan, and PECAM. Gene expression of select genes involved in tumor progression, ECM remodeling, and osteoclastogenesis were validated via quantitative reverse transcription-PCR in an independent cohort. We propose that osteosarcoma tumor-driven changes in the bone microenvironment contribute to the chemotherapy-resistant phenotype and offer testable hypotheses to potentially enhance therapeutic response.