Historical, current and future aspects of osteosarcoma treatment

Monocarboxylate Transporter 4 (MCT4) Overexpression Is Correlated with Poor Prognosis of Osteosarcoma

Background

Monocarboxylate transporter 4 (MCT4) is a critical element for glycolytic metabolism and malignant behaviors in many tumor cells. This study aimed to determine the expression level of MCT4 protein and its prognostic value in osteosarcoma.

Material/Methods

MCT4 expression was detected via immunohistochemical and Western blot analysis for 100 osteosarcoma patients. The correlation between MCT4 expression and clinical factors among the patients was analyzed using the chi-square test. Overall survival of osteosarcoma patients was estimated by Kaplan-Meier analysis. The prognostic value of MCT4 was evaluated using Cox regression analysis with adjustments for clinicopathological variables.

Results

MCT4 expression was significantly upregulated in osteosarcoma tissues compared with that in adjacent normal ones, detected via both immunohistochemical and Western blot analyses. High MCT4 expression showed a positive association with distant metastasis (P=0.000) and recurrence (P=0.000) of osteosarcoma. Kaplan-Meier analysis indicated that overall survival of osteosarcoma patients was significantly higher in the low MCT4 expression group than in the high expression group (log-rank test, P<0.001). Multivariate analysis indicated that MCT4 expression and clinical stage, which are tightly related to the prognosis of osteosarcoma, might be independent predictors of osteosarcoma prognosis.

Conclusions

High MCT4 expression appears to contribute to osteosarcoma progression and the upregulation of MCT4 may predict poor prognosis among osteosarcoma patients.

Inhibitory effects of low-intensity pulsed ultrasound sonication on the proliferation of osteosarcoma cells

To date, there is limited data on the biological effects of low-intensity pulsed ultrasound (LIPUS) on primary malignant bone tumors. The purpose of the present study was to investigate the antitumor effects of LIPUS on osteosarcoma cells. The effects of LIPUS on cell viability, induction of apoptosis, mitochondrial membrane potential and intracellular signaling molecules in the LM8 osteosarcoma cell line were investigated. LIPUS inhibited cell viability (P=0.0022) and mitochondrial membrane potential (P=0.0019) in LM8 cells. Flow cytometry analysis and terminal deoxynucleotidyl transferase dUTP nick end labeling staining revealed significantly higher numbers of apoptotic (P<0.0001) and necrotic cells (P=0.0091) compared with cells without treatment. LIPUS treatment significantly increased phosphorylated Akt (P<0.0001) and IκBα (P=0.0001) levels, and reduced phosphorylated mitogen-activated protein kinase 7 (P<0.0001) and phosphorylated checkpoint kinase 1 (P=0.0008) levels. These results suggest that LIPUS is a non-invasive adjuvant therapy that is able to inhibit cellular proliferation in osteosarcoma cells.

Pediatric Malignant Bone Tumors: A Review and Update on Current Challenges, and Emerging Drug Targets

Osteosarcoma (OS) and the Ewing sarcoma family of tumors (ESFT) are the most common malignant bone tumors in children and adolescents. While significant improvements in survival have been seen in other pediatric malignancies the treatment and prognosis for pediatric bone tumors has remained unchanged for the past 3 decades. This review and update of pediatric malignant bone tumors will provide a general overview of osteosarcoma and the Ewing sarcoma family of tumors, discuss bone tumor genomics, current challenges, and emerging drug targets.

Activity of the novel dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor NVP-BEZ235 against osteosarcoma

Recent studies have identified that constitutively active phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling is an important feature of osteosarcoma, where it promotes cell proliferation, survival, and chemo-resistance. Here, we studied the therapeutic potential of NVP-BEZ235, a novel dual PI3K/mTOR dual inhibitor, on osteosarcoma cells in vivo and in vitro. NVP-BEZ235 was cytotoxic and cytostatic to a panel of osteosarcoma lines (MG-63, U2OS and SaOs-2), where it induce apoptosis and cell-cycle arrest. At the molecular level, NVP-BEZ235 inhibited PI3K-AKT-mTORC1 activation and downregulated cyclin D1/cyclin B1 expressions, while increasing MEK/Erk phosphorylation in osteosarcoma cells. MEK/Erk inhibitors PD98059 and MEK-162 increased NVP-BEZ235 activity on osteosarcoma cells. In vivo, oral NVP-BEZ235 inhibited U2OS xenograft in SCID mice, and its anti-tumor efficiency was further enhanced by MEK-162 co-administration. Taken together, our findings indicate that dual inhibition of PI3K and mTOR with NVP-BEZ235, either alone or in combination with MEK/Erk inhibitors, may be an efficient treatment for osteosarcoma.

Bufotalin-induced apoptosis in osteoblastoma cells is associated with endoplasmic reticulum stress activation

The search for novel and more efficient chemo-agents against malignant osteoblastoma is important. In this study, we examined the potential anti-osteoblastoma function of bufotalin, and studied the underlying mechanisms. Our results showed that bufotalin induced osteoblastoma cell death and apoptosis in dose- and time-dependent manners. Further, bufotalin induced endoplasmic reticulum (ER) stress activation in osteoblastoma cells, the latter was detected by the induction of C/EBP homologous protein (CHOP), phosphorylation of inositol-requiring enzyme 1 (IRE1) and PKR-like endoplasmic reticulum kinase (PERK), as well as caspase-12 activation. Conversely, the ER stress inhibitor salubrinal, the caspase-12 inhibitor z-ATAD-fmk as well as CHOP depletion by shRNA significantly inhibited bufotalin-induced osteoblastoma cell death and apoptosis. Finally, by using a mice xenograft model, we demonstrated that bufotalin inhibited U2OS osteoblastoma cell growth in vivo. In summary, our results suggest that ER stress contributes to bufotalin-induced apoptosis in osteoblastoma cells. Bufotalin might be investigated as a novel anti-osteoblastoma agent.

Salinomycin activates AMP-activated protein kinase-dependent autophagy in cultured osteoblastoma cells: a negative regulator against cell apoptosis

Background

The malignant osteoblastoma has poor prognosis, thus the search for novel and more efficient chemo-agents against this disease is urgent. Salinomycin induces broad anti-cancer effects both invivo and invitro, however, its role in osteoblastoma is still not clear.

Key Findings

Salinomycin induced both apoptosis and autophagy in cultured U2OS and MG-63 osteoblastoma cells. Inhibition of autophagy by 3-methyladenine (3-MA), or by RNA interference (RNAi) of light chain 3B (LC3B), enhanced salinomycin-induced cytotoxicity and apoptosis. Salinomycin induced a profound AMP-activated protein kinase (AMPK) activation, which was required for autophagy induction. AMPK inhibition by compound C, or by AMPKα RNAi prevented salinomycin-induced autophagy activation, while facilitating cancer cell death and apoptosis. On the other hand, the AMPK agonist AICAR promoted autophagy activation in U2OS cells. Salinomycin-induced AMPK activation was dependent on reactive oxygen species (ROS) production in osteoblastoma cells. Antioxidant n-acetyl cysteine (NAC) significantly inhibited salinomycin-induced AMPK activation and autophagy induction.

Conclusions

Salinomycin activates AMPK-dependent autophagy in osteoblastoma cells, which serves as a negative regulator against cell apoptosis. AMPK-autophagy inhibition might be a novel strategy to sensitize salinomycin’s effect in cancer cells.

MACC1 is involved in the regulation of proliferation, colony formation, invasion ability, cell cycle distribution, apoptosis and tumorigenicity by altering Akt signaling pathway in human osteosarcoma

There is mounting evidence that metastasis-associated in colon cancer-1 (MACC1) plays pivotal roles in development and progression of many tumors, particularly in osteosarcoma (OS). However, its precise roles and molecular mechanisms remain to be delineated in OS. In the current study, we found that the levels of MACC1 mRNA and protein in four OS cell lines (MG-63, HOS, SaOS-2 and U2OS) were significantly higher than that in hFOB1.19 osteoblast (P < 0.05). The vector pcDNA-MACC1 contributed to the increase of MACC1 level in MG-63 cells, whereas MACC1 siRNA evoked the decrease of MACC1 level in U2OS cells. In addition, MACC1 downregualtion caused the inhibition of cell proliferation in vitro, colony formation, invasion and tumor growth in vivo, arrested cell cycle in G0/G1 phase and induced cell apoptosis in U2OS cells, and reversed effects were observed in MG-63 cells by MACC1 upregulation. Most notably, MACC1 depletion markedly inactivated Akt signaling pathway in U2OS cells, conversely, MACC1 upregulation evidently activated Akt signaling pathway in MG-63 cells. Collectively, our data presented herein suggest that biological implications triggered by MACC1 may be tightly associated with the status of Akt signaling pathway in OS.

Role of integrin-linked kinase in osteosarcoma progression

Although integrin-linked kinase (ILK) has been suggested to play a role in the tumorigenesis of a number of human epithelial carcinomas, little is known of its role in musculoskeletal sarcoma. The authors studied ILK expression by immunohistochemistry using osteosarcoma prechemotherapy specimens from 56 patients, and investigated the prognostic implications of the findings obtained. It was found that ILK overexpression was significantly correlated with the presence of distant metastasis (p = 0.008) and that it was an independent prognostic factor for both poor overall survival and poor event-free survival (p = 0.015 and 0.010, respectively). During a transfection experiment conducted by transfecting osteosarcoma cells with ILK siRNA, VEGF concentrations were measured using an ELISA kit, and then compared with those of untransfected controls to evaluate its angiogenic effects. In addition, apoptotic percentages were measured by Annexin-V flow cytometry, and invasive properties were evaluated by measuring the numbers of non-migrating cells in a Boyden chamber. It was found that ILK downregulation significantly decreased angiogenesis, increased apoptosis, and decreased invasiveness of osteosarcoma cells. These results show that ILK is a promising prognostic factor in osteosarcoma and a novel potential therapeutic target for the treatment of osteosarcoma.

High expression of MACC1 predicts poor prognosis in patients with osteosarcoma

Increasing evidence has demonstrated that high metastasis-associated in colon cancer-1 (MACC1) level is tightly associated with the development, progression, and poor prognosis of a variety of tumors. However, the relationship between MACC1 and the occurrence, development, and progression of osteosarcoma (OS) remains to be clarified. To facilitate and deepen the understanding of the associations of MACC1 with the development and progression of OS, in the current study, we detected the expressions of MACC1 mRNA and protein, and investigated the relationship between MACC1 expression and prognosis of the patients with OS. Our findings demonstrated that expressions of MACC1 mRNA and protein in OS tissues were significantly higher than those in paired normal bone tissues (P < 0.05). Additionally, the level of MACC1 mRNA in the patients with higher clinical stage and distant metastasis was markedly higher than those with lower clinical stage and without metastasis (P < 0.05). Furthermore, high MACC1 level was closely correlated with clinical stage and distant metastasis (P < 0.05), but not related to the patients' age, gender, tumor size, and anatomical location (P > 0.05). Stepwise investigation revealed that survival time of the patients with high MACC1 level was obviously lower than that with low MACC1 level (P < 0.05). Collectively, our data suggest that MACC1 may play important roles in the development and progression of OS, and thus may be considered as a novel molecular target for therapy of the patients with OS.

Perifosine induces cell apoptosis in human osteosarcoma cells: new implication for osteosarcoma therapy?

Despite the advances of adjuvant chemotherapy and significant improvement of survival, the prognosis for patients with osteosarcoma is generally poor. The search for more effective anti-osteosarcoma agents is necessary and urgent. Here we report that perifosine induces cell apoptosis and growth inhibition in cultured human osteosarcoma cells. Perifosine blocks Akt/mTOR complex 1 (mTORC1) signaling, while promoting caspase-3, c-Jun N-terminal kinases (JNK), and p53 activation. Further, perifosine inhibits survivin expression probably by disrupting its association with heat shock protein-90 (HSP-90). These signaling changes together were responsible for a marked increase of osteosarcoma cell apoptosis and growth inhibition. Finally, we found that a low dose of perifosine enhanced etoposide- or doxorubicin-induced anti-OS cells activity. The results together suggest that perifosine might be used as a novel and effective anti-osteosarcoma agent.

Knockdown of AXL receptor tyrosine kinase in osteosarcoma cells leads to decreased proliferation and increased apoptosis

Dysregulation of the Axl receptor tyrosine kinase (RTK) has been implicated in the development and progression of a variety of malignancies. Axl is known to activate strong anti-apoptotic signaling pathways that promote oncogenesis. However, the role of Axl plays in osteosarcoma (OS) remains elusive. The present study aimed to investigate the clinical significance and function of Axl in human OS. Forty cases of OS and corresponding adjacent non-cancerous tissues (ANCT) were collected. The expression of Axl was assessed using immunohistochemical assay through tissue microarray procedure. A loss-of-function experiment was performed to investigate the effects of small hairpin RNA (shRNA)-mediated knockdown of Axl on the expression of p-AKT, poly ADP-ribose polymerase (PARP) and Ki-67, the proliferative activities, indicated by MTT assay, and the apoptotic index in OS MG-63 cells. As a result, the expression of Axl was found in OS tissues with higher strong reactivity rate, compared with the ANCT (75.0 percent vs 20.0 percent, P=0.000), but it did not associate with the age, gender, tumor size, TNM staging and distant metastases (each Pgreater than0.05). Furthermore, knockdown of Axl inhibited the proliferative activities and induced apoptosis in MG-63 cells with decreased expression of p-AKT, and Ki-67 and increased expression of PARP. In conclusion, our findings suggest that Axl is highly expressed in most of the OS tissues compared with the ANCT, and knockdown of Axl inhibits proliferation and induces apoptosis of OS cells possibly through downregulation of the AKT pathway, suggesting that our findings may provide new insights into the potential therapeutic target for cancer.

CD133 expression predicts lung metastasis and poor prognosis in osteosarcoma patients: A clinical and experimental study

Identifying prognostic factors for osteosarcoma (OS) aids in the selection of patients who require more aggressive management. CD133 has been found to be a prognostic factor of certain tumor types. However, the association between CD133 expression and the prognosis of OS remains unknown. In this study, we analyzed the association of CD133 expression in OS with clinical factors and overall survival, and further investigated its potential role in metastasis in vitro. We found CD133 expression in 65.7% (46/70) of OS samples using immunohistochemistry, and it was positively correlated with lung metastasis analyzed by Chi-square test (P=0.002) and shorter overall survival time using the Kaplan-Meier method compared by log-rank test (P=0.000). Multivariate analysis showed that CD133 expression was an independent prognostic factor of patients with OS. To test for direct participation of CD133, we separated CD133⁺ and CD133⁻ cells in the MG63 cell line using magnetic-activated cell sorting and found that CD133⁺ cells were more active in migration by scratch wound-healing assay and invasion by Matrigel invasion assay compared with CD133⁻ cells. Elevated mRNA expression of the stemness gene octamer-binding transcription factor 4 (Oct-4) and NANOG, and the metastasis-related receptor C-X-C chemokine receptor type 4 (CXCR4) were also found in CD133⁺ cells by reverse transcription-polymerase chain reaction. Thus, expression of CD133 was correlated with lung metastasis and poor prognosis in OS patients. CD133⁺ cells may be a type of cancer stem cell with high expression of self-renewal capacity and metastasis-related genes.

High serum alkaline phosphatase cooperating with MMP-9 predicts metastasis and poor prognosis in patients with primary osteosarcoma in Southern China

Background

Osteosarcoma is a malignant tumor with high ability to form invasion and metastasis. Identifying prognostic factor in osteosarcoma is helpful to select those patients for more aggressive management. Our study evaluated serum alkaline phosphatase (ALP) cooperating with matrix metalloproteinase-9 (MMP-9) as an important prognostic predictor for local recurrence and distant metastasis of osteosarcoma.

Methods

177 cases were included from the osteosarcoma patients treated at 1st Affiliated Hospital of Sun Yat-sen University (1999-2008). Pre-chemotherapy serum ALP (pre-ALP) were studied and correlated with tumor recurrence, lung metastasis and patient survival. MMP-9 protein in tumor tissues was detected by immunohistochemistry and correlated with pre-ALP level.

Results

Pre-ALP were partitioned into normal, high, and very high groups, in each group the incidence of metastases was 12.2%, 21.2% and 34.6%, respectively (p = 0.007). In the three groups the mean disease-free survival (DFS) was 57 ± 3.15, 28 ± 3.57 and 14 ± 3.35 months, respectively (p < 0.001); overall survival (OS) was 92 ± 26.89, 39 ± 8.61 and 17 ± 5.07 months, respectively (p < 0.001). By multivariate analysis, elevated serum pre-ALP were associated with shorter DFS (p = 0.018) and OS (p = 0.031). If elevated ALP levels decreased after clinical treatment, the incidence of lung metastasis rate decreased (p = 0.028); DFS and OS were both prolonged (p < 0.001). Pre-ALP was also positively correlated with MMP-9 expression (p = 0.015) in tumor tissue.

Conclusions

Pre-ALP was an independent prognostic factor for the survival of osteosarcoma patients in south China, and correlated with MMP-9 expression and lung metastasis. ALP can also serve as a prognostic marker for treatment, and merit large-scale validation studies.

Antitumor effects of telomerase inhibitor TMPyP4 in osteosarcoma cell lines

Telomere studies in carcinomas have been extensively reported for prognostic utility and effective methods for targeting telomerase therapy has been described, but efficacy of telomerase inhibitor remained unknown in sarcoma cells. In this study, we investigated the effects of telomerase inhibitor cationic porphyrin TMPyP4 on telomerase activity, telomere length, cell growth, and apoptosis in osteosarcoma cell lines. TMPyP4 significantly inhibited telomerase activity in telomerase positive HOS and Saos-2, but not in MG-63. TMPyP4 significantly induced telomere shortening, and inhibition of the cell growth in HOS and Saos-2 with over 17% apoptosis rates. In terms of MG-63, TMPyP4 did not induce inhibition of both telomerase activity and cell growth, although it induced significant telomere shortening. Telomere length after treatment was 5.60 kb in HOS, 4.00 kb in Saos-2, and 9.89 kb in MG-63. These results may suggest that both telomerase activity loss and sufficient telomere shortening are necessary to inhibit cell growth in telomerase positive osteosarcoma cells. TMPyP4 did not induced telomere shortening but significantly inhibited the growth with 22.6% apoptosis rate in telomerase negative with extremely longer telomere-U2OS, may indicating the antitumor effect of TMPyP4 may be related to DNA damage including telomere dysfunction through G-quadruplex stabilization, independent on telomere length.

Expressions of p53, c-MYC, BCL-2 and apoptotic index in human osteosarcoma and their correlations with prognosis of patients

BACKGROUND

Nowadays it remains a controversial issue whether a correlation exists between the apoptosis rate of tumor tissue and the prognosis of the patients. The aim of the study is to investigate the relationships of apoptotic genes and apoptotic index of osteosarcoma tissue to prognosis of the patients, meanwhile to explore the valid prognostic biomarkers of osteosarcoma that will enhance efficacy of clinical treatments for osteosarcoma.

METHODS

In our studies, the immunohistochemical ABC and terminal DNA breakpoints in situ 3-hydroxy end labeling (TUNEL) techniques were used to detect the expressions of p53, c-MYC, BCL-2 and apoptotic index in 56 osteosarcoma specimens. The relationships between apoptotic genes expression and apoptotic index in osteosarcoma tissue and their correlations with pathologic classification and prognosis of osteosarcoma cases were analyzed.

RESULTS

We found that the expressions of p53, c-MYC, and BCL-2 were negatively correlated with apoptotic index of osteosarcoma tissue, were not correlated with pathological types of osteosarcoma, and were closely related to prognosis of the patients. Moreover, apoptotic index of osteosarcoma tissue was positively correlated with the long term survival of the patients.

CONCLUSION

We concluded that the expressions of p53, c-MYC, BCL-2 protein and apoptotic index could be used as potential biomarks for predicting the progression and prognosis of osteosarcoma, and for optimizing clinical treatments.

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.

Clinical Outcomes of 54 Pelvic Osteosarcomas Registered by Japanese Musculoskeletal Oncology Group

BACKGROUND

To determine the clinical outcomes in patients with pelvic osteosarcoma, we reviewed the experience with 54 pelvic osteosarcoma patients.

METHODS

Thirty-five patients underwent surgical treatment with 30 undergoing limb salvage procedures and 5 requiring hemipelvectomies.

RESULTS

Oncological outcome was continuously disease free in 12 cases, no evidence of disease in 3, alive with disease in 3, died of disease in 34 and died of other causes in 2. The 5-year survival rate was 29.5%. For the patients who underwent surgery, statistically significant prognostic factors were chemotherapy, surgical margin, tumor location in sacrum, efficacy of chemotherapy, local recurrence, metastasis and treatment for metastases. With univariate analysis, local recurrence, surgical margin and tumors resected from the sacrum were significant prognostic factors for metastasis. Surgical margin, tumor resected from sacrum and metastasis were significant prognostic factors for local recurrence. With regard to postoperative functional mobility, patients with tumors resected from the sacrum exhibited poorer functional mobility when compared with other sites.

CONCLUSIONS

Patients with tumors located in the sacrum had worse prognosis, and significant prognostic factor for local recurrence and metastasis. Treatment of pelvic osteosarcoma especially located in the sacrum requires new approaches and further improvements in order to ensure successful outcomes.

Treatment effects in pediatric soft tissue and bone tumors: practical considerations for the pathologist

Dramatic improvements in survival for children with cancer have led to increased numbers of posttreatment pathologic specimens, particularly in bone and soft tissue sarcomas. Current therapeutic protocols in North America require specific pathologic classification and stratify patients based on clinical, biologic, and pathologic features. For osteosarcoma, the pathologic response to therapy predicts prognosis and modifies the treatment regimen. Ongoing studies aim to assess the response to therapy and outcome in other types of soft tissue and bone tumors. The pathologic evaluation of pretreatment and posttreatment specimens is critical for therapeutic decisions and prognostic assessment. A standardized approach to posttherapy pathologic specimens, with attention to appropriate use of ancillary tests, and assessment of clinical and biologic significance of therapy-induced pathologic changes has significance for patient management and treatment protocols.

Metastatic osteosarcoma causing intussusception

Osteosarcoma is the most common malignant bone neoplasm. It has a very high metastatic potential, and lungs are the most common site of metastasis followed by bones. Multiagent chemotherapy has been reported to alter the biological behavior of the disease so that the tumor metastasizes to more rare sites such as brain, bowel, and soft tissues. The authors report a case of jejuno-jejunal intussusception caused by metastases from osteosarcoma.

Osteosarcoma of the pelvis--oncological results of 40 patients registered by The Netherlands Committee on Bone Tumours

AIM AND METHODS

We reviewed the oncological outcome in 40 consecutive patients with an osteosarcoma of the pelvic region, registered in the files of the Netherlands Committee on Bone Tumours (NCBT) between 1978 and 1995.

RESULTS

Six patients had distant metastases at initial presentation (Enneking stage IIIB), 33 patients had stage IIB osteosarcoma and one patient stage IB osteosarcoma. Patients with metastases were treated with chemotherapy (four) or palliative procedures (two). Patients with non-metastatic osteosarcoma were treated with surgical procedures with (14) or without (four) neoadjuvant chemotherapy, chemotherapy without surgical resection (nine), or palliative procedures (seven). The median survival of stage IIB and IIIB osteosarcoma was 14 months (2-175) and 7.5 months (2-16), respectively. Survival in patients with stage IIB osteosarcoma treated with curative procedures was significantly better (P<0.0006) compared with stage IIB patients treated with palliative intent. Two and 5-year survival for patients with curatively treated stage IIB osteosarcoma was 35% and 26%, respectively; distant metastases had developed in 65% of these patients. On univariate analysis, positive prognostic factors for patients with stage IIB osteosarcoma were complaints of 3 months or less before initial presentation, tumour size of 8 cm or less, osteoblastic subtype, surgical resection of the primary tumour and limb salvage procedures.

CONCLUSION

In conclusion, the prognosis of pelvic osteosarcoma remained poor despite modern multimodality treatment regimens, including neoadjuvant chemotherapy.